Dynamic Thermal Simulation & Systems Sizing Report

Transcription

1 Dynamic Simulation & Systems Sizing Report Hillside Cottage Sevenmarks Hampshire Project Number: GRL Revision: Draft/For Comment Date: Richard Tibenham Consulting All rights reserved.

2 2 This report has been produced by: Richard Tibenham (Director) Greenlite Assessors 11 Yarborough Terrace, Lincoln. LN1 1HN T: E: For: Ian de-peyrecave Perry+Bell Ltd 21 Woodstock Street London W1C 2AP

3 3 Contents: Executive Summary 1.0 Introduction Simulated Parameters Location/weather file Geometry Construction Fabric Construction Detailing Air tightness HVAC Systems; Overview MVHR Unit & Earth Tube Modelling DHW Heating System Internal Gains; Occupants, Lighting & Equipment Humidity Gains and CO2 levels Control of Windows and Doors Simulation Results Study into Local Space Heating Demand Study into Internal Temperatures Study into performance of Earth Tube and MVHR unit Study of Suitable Sizing of the Store Investigation into the relationship of Store Capacity and 63 Auxiliary Inputs based on Solar Inputs Alone 4.2 Investigation into the Effect of Additional Insulation to the Store Investigation into the Inclusion of Photovoltaic Array Inputs via Immersion 71 Heaters 4.4 Investigation into the Effect of a Dual Store System Conclusions & recommendations r Conclusions Recommendations 80

4 4 Schedule of Revisions: Revision: Date Notes: Assembled by: Draft/for Comment Based on documentation provided by client. Suitable assumptions made where information is not yet available and described within report. RT Prepared by: Richard Tibenham... Director

5 5 Executive Summary This report has been commissioned by Ian de-peyrecave to aid in the design of Hillside Cottage, Four Marks, Hampshire. The building is designed around the philosophy of very low energy demand, of which, a substantial proportion is to be generated using on site active solar thermal systems. This philosophy shall be achieved through the reduction of energy demand using Passivhaus design and construction principles; namely very high levels of thermal insulation, thermal bridge free junction detailing, very high levels of air tightness, predominantly south orientated glazing and a mechanical ventilation system with heat recovery and an earth tube frost protection supply routing. Heating to the dwelling shall be achieved through the use of a low temperature hot water radiator circuit, utilising over-sized low temperature radiators operating at 45 C. An array of evacuated tube solar thermal collectors shall be located on the roof of the building, to provide for domestic hot water, and supplement to some degree energy for space heating. The principle purpose of this report is to investigate appropriate sizing of this active solar thermal system in the context of the building s space heating and domestic hot water loads. A detailed dynamic thermal simulation has been conducted using IES Virtual Environment software, in order to establish the buildings space heating demand and in order to investigate further a range of aspects of the design, including space heating system design & sizing and overheating analysis. Further detailed modelling of the solar thermal system has been conducted using Valentin T*Sol simulation software, owing to the approximations for solar thermal systems modelling applied within the IES software. It is concluded that where a 1500ltr thermal store is included, approximately 50% of the building s domestic hot water and space heating demands shall be met through local renewable solar systems. In addition, energy equal to approximately 25% of the domestic hot water and space heating demand is likely to be available for export to the electrical grid during the summer, resulting in a net energy provision from renewable technologies of around 75% of the annual space heating and domestic hot water energy demand.

6 6 1.0 Introduction Hillside Cottage, located within the village of Four Marks, Hampshire is the proposed dwelling for owner/builder, architect and client, Ian de-peyrecave. The dwelling is built into a hillside over three floors and includes four bedrooms, two reception rooms, four en-suite bathrooms and two kitchens (main kitchen and utility). The building is located with the longitudinal axis of the building running directly east-west, with the front elevation of the building orientated due south. The roof, at a 30 pitch, features a vertical element at the top for the locating of winter sun optimised solar thermal collectors. The design intent of the building is to operate with a very low energy demand, and to provide for much of this demand through onsite renewable energy. It is designed with the intent of potential future off-grid operation. The building is built using Passivhaus design principles, featuring very high efficiency thermal insulation, very high levels of air tightness, thermal bridge free detailing, triple glazing, a mechanical ventilation system with earth tube and predominantly south facing glazing. It is intended that the building shall provide for as much of the energy demand as is feasibly possible through onsite solar technologies. Solar thermal collectors shall be located on the vertical element of the roof in order to optimise winter time gains. A solar PV array shall be present on the 30 pitched roof for supplementing hot water and space heating all year round, but shall produce the highest yield during the summer months. Both systems shall supply heat to one or more thermal stores, from which a low temperature hot water (LTHW ) circuit shall run, feeding over-sized low temperature (45 C) radiators. Domestic hot water (DHW) shall also run from the same thermal store(s). This report investigates the design of the building through the investigation of the heating demand likely from such a specification and a detailed study of the available solar energy at the site. Conclusions are drawn concerning the specification of plant required to yield as much solar energy as is feasibly possible. A full description of this process is laid out across the following sections of the report.

7 7 2.0 Simulated Parameters 2.1 Location/weather file; Fig 1. Location map Obscured for client confidentiality The proposed site of the building is located at Four Marks, Hampshire, approximately fourteen miles east of Winchester and twenty-four miles north east of Southampton. As such, the CIBSE Southampton TRY05 weather file has been selected for this simulation. The TRY (Typical Reference Year) file adopts typical weather data for this location. A minimum temperature of -5.7 C is utilised within the heating simulation. For overheating risk analysis, the CIBSE Southampton DSY05 weather file has been selected, accounting for Design Summer Year weather data, which accounts for higher summer time temperatures.

8 8 2.2 Geometry The building has been modelled using the IES native modelling program ModelIT and accounts for all shading surfaces to the building and local shading objects which will have an effect on solar gains to the building. Note that trees directly to the south of the property are accounted to be removed. Modelling of the building fabric is based upon architectural drawings provided by the client, with the addition of a speculative airing cupboard in the space beneath the lower ground floor stairs. The building is modelled as indicated on architectural drawings, with the front elevation of the building orientated due south. Construction Geometry used within the simulations is shown below: Fig 2. Aerial View

9 Fig 3. South Elevation Fig 4. North Elevation 9 Fig 5. West Elevation Fig East Elevation Fig South East Aerial View Fig South West Aerial View Fig 9. North West Aerial View Fig 10. North East Aerial

10 10 Geometric Modelling Notes; The architectural information submitted does not confirm the build-up of certain areas of the construction. All roofs are accounted to be warm roof constructions, including those above the Utility Kitchen and Study/Office. Fig 11.. Utility Kitchen Roof Fig 12.. Study Roof Warm Roof Warm Roof

11 Construction Fabric Construction fabric used within the calculation is based upon architectural information provided by the client and amended where necessary to create a thermal envelope achieving a U-Value of 0.1 W/m².k ¹ to the floor, roof and walls. Glazing information is based upon architectural window schedules and information provided by the proposed glazing manufacturer, Gaulhofer (via EcoWin). When detailed construction build-ups have been confirmed, accurate U-Value calculations can be made and used to update the simulation if necessary. The following construction fabric has been used within this assessment. Note the descriptions provide only an approximate description of the actual build-up; necessary in order to account for thermal bridging and incontinuities in the fabric. The design U-values and thermal mass figures are of principle importance; Opaque Construction Fabric Fig 13.. Table of Opaque Construction Elements Element Description Composition U-Value (W/m².K) External Walls Mass KJ/(m².K) External walls (Lower GF) External walls (Upper GF + FF) Retaining Wall Floors Lower Ground Floor Construction Ground Floor Construction Roof Warm Roof Construction -100mm Outer Brick leaf -306mm Drittherm 32 Mineral wool or similar -25mm Gpypsum Plasterboard -10mm Timberboard -308mm Drittherm 32 Minerla wool or similar -25mm Gpypsum Plasterboard -220mm Concrete -304mm Dritherm 32 Mineral wool or similar -25mm Gypsum Plasterboard - 160mm PUR Rigid foam Insulation - 100mm Cast Concrete -50mm Screed -170mm PUR Rigid Foam Insulation -100mm Cast Concrete -50mm Screed - Tiles and felt -313mm Dritherm 32 Mineral Wool or similar -12.5mm Gypsum Plasterboard

12 12 Internal Partitions Lightweight Partition Insulated Plant Room Partition (Advised)* Internal Floors Plasterboard Ceilings Timber Intermediate Floor Doors - 3mm plaster skim -25mm Gypsum Plasterboard -70mm Void -25mm Gypsum Plasterboard - 3mm plaster skim -12.5mm Gypsum plaster board -200mm Dritherm 32 or similar -100mm Brickwork -3mm Plaster skim -12.5mm Gypsum Plasteboard -10mm Synthetic Carpet -18mm Chipbaord External doors -12mm Oak Veneer -28mm PUR foam -12mm Oak Veneer 0.63 (estimate) Internal doors -8mm Oak veneer -30mm Chipboard -8mm Oak veneer *It is recommended to install an insulated partition between occupied areas and the plant room in order to avoid summer time heat gains which may result from high temperatures within thermal stores.

13 Glazing: Glazing parameters have been input based on architectural window schedule drawings and information provided by EcoWin. Certain aspects of the parameters input into the simulation have been estimated due to information not being available. In order to fully account for the windows as specified, the following information should also be provided; Total external dimensions Glazed area only Frame material U-values The following information has been input into the assessment; Fig 14.. Table of Glazing Elements Glazing U-Value (W/m².K) Frame Factor Glazing Frame Total g-value LT-value A1 (A) % A2 (B) % A3 (C) % A4 (D) % A5 (E) % A6 (F) % A7 (G) % A8 (H) % A9 (I) % A10 (J) % A11 (K) % A12 (L) % A13 (M) % A14 (N) % A15 (O) % A16 (P) %

14 Construction Detailing Fabric junctions are not accounted for within the IES software. As such, any additional heat leakage via fabric junctions should be accounted for as an addition to the fabric U-Values in which the junctions are present. The simulation described within this report accounts for thermal bridge free detailing to all construction junctions, as would be necessary for Passivhaus design. When construction junctions are fully defined, should these not achieve thermal bridge free detailing, these can be assessed in order to establish a Psi-Value for the junction (W/m) and subsequently incorporated into the IES simulation. 2.5 Ait Tightness Air permeability has been modelled into all areas at a rate of 0.01ACH. This equates to the Passivhaus standard of air tightness of 0.6ACH@50Pa +/-, corrected for normal operating pressures. A reduction factor of 1/60 has been applied in accordance with the guidance of CIBSE TM23 Testing Buildings for Air Leakage.

15 HVAC Systems; Overview HVAC systems have been modelled into the simulation using the IES Apache HVAC System Simulation Interface, which allows much greater control of HVAC systems than modelling within the IES Apache Simulation alone. The system accounts for a thermal store, heated using solar thermal collector inputs and supplementary heat inputs from a gas fired boiler. The thermal store is used for the provision of space heating, via LTHW over-sized radiators, operating at a 45 C flow temperature. DHW services are also drawn from the same single thermal store. Mechanical ventilation is assigned based upon the PAUL Novus MVHR unit, though this is purely indicative units providing similar levels of heat recovery may be used without detriment to the simulated thermal outcomes. The supply routing to the MVHR unit accounts for an earth tube subsurface frost protection pipe raising the flow temperature during the winter and reducing it during the summer. The ventilation system is assigned with controls to modulate the flow rate dependent upon temperature, moisture and CO2 concentrations allowing automated control of the flow rate to maintain suitable internal conditions, with no need to disable the unit when windows are opened. A summer-time by-pass damper is modelled within the unit. Solar collectors are modelled upon the roof of the building initially at the vertical inclination described on the clients drawings, however the performance at pitched orientations are also investigated.

16 Space Heating Parameters After investigation of the thermal behaviour of the building, wet radiators are accounted for in the following rooms; -01 Reception -01 Bedroom 4-01 Bedroom 3-01 Airing Cupboard (beneath stair, speculative) 00 Main Reception 00 Study Office 00 Utility Kitchen 00 Guest Room 00 Lobby 00 Master Bedroom These are rooms which have either mechanical supply, or are on an air transition path, thus allowing warm air created via the radiators to be drawn to locations with mechanical extract. Where radiators are located within rooms with mechanical extract, this warm air is removed directly. A proportion of heat will be recovered via the heat recovery unit, however where local heating via radiators is not including within a room, space heating is purely via the ventilation system, for which the flow rate may be reduced due to low CO2 or moisture levels. Heating via air only is therefore considered less controllable than that of heating using radiators. Radiators are assigned to become active dependent upon two thermostats, located within; 00 Lobby (adj. Utility Kitchen) -01 Circulation/Stair When either of these thermostats registers a temperature <18 C, the LTHW radiator circuit turns ON. The circuit turns OFF when the zone reaches 20 C. Note that it is important to locate the ground floor thermostat within the Lobby area; this is identified to be one of the coldest areas in the house due to the high external fabric to volume ratio. All radiators are assigned to be equipped with TRVs to modulate the flow rate to the radiators locally. These are assigned to provide full flow <18 C and zero flow >20 C. The flow temperature to radiators is assigned to be 45 C. It is recommended to provide a thermostatic blending valve to the LTHW radiator circuit to blend the flow temperature to 45 C. This shall prevent excessive draw-off from the thermal store. One such valve is; Full listings of the calculated capacity of radiators is located within fig. 55 of the report.

17 MVHR Unit & Earth Tube Modelling Mechanical ventilation parameters are based around the PAUL Novus 300 MVHR unit, though this only provides an indication of the possible performance of an MVHR unit and is not prescriptive. Supply and extract locations are based on those shown within the clients drawings. Supply and extract rates have been assigned based on the minimum flow rates as recommended for Passivhaus design (30m³/hr/person = 8.33l/s/person), though these are assign to regulate dependent upon the system sensor inputs detailed below. The following flow rates have been assigned; Fig 15.. Table Mechanical Supply and Extract Rates Supply Extract Supply Zones Min. Rate (l/s) Design Rate (l/s) Rate Max. (l/s) Extract Zones Min. Rate (l/s) Desig n Rate (l/s) Rate Max. (l/s) Reception Airing Cup'd Bedroom Bedroom 4 En-suite Bedroom Bedroom 3 En-suite Main Reception Kitchen Dining Guest En-suite Study/Office Utility Kitchen Guest Bedroom Master En-suite Master Bedroom Void Above Entrance Hall TOTAL The system accounts for controls via; Internal Temperature Relative Humidity CO2 sensors Assigning such controls allows the system to automatically modulate the flow rate dependent upon internal environmental conditions, with little need for user interaction. During the transition months, where windows are opened, the system will automatically reduce the flow rate, or turn off completely, if there is no need for mechanical ventilation.

18 Internal temperature sensors -for space heating; The MVHR unit is assigned to regulate the air flow rate dependent upon internal temperature, in order to provide maximum heating via the ventilation system when required and no flow when not required. The flow rate is regulated via a thermostat located within the Lobby adjacent the Utility Kitchen. The signal is ON until the thermostat within the Lobby registers >18 C. The control provides a signal to provide full ventilation at <16 C, tending towards zero ventilation at >18 C, as shown below: Fig 16.. Space Heating Thermostat Settings Internal temperature sensors -for space cooling; A separate thermostatic control has also been located within the Main Reception to register high internal temperatures. The signal is assigned to be ON when the internal temperature within the Main Reception is >22 C. The flow rate is assigned to be zero where the internal temperature is <22 C, tending towards full capacity when the internal temperature is >26 C, allowing cooling via ventilation when necessary.

19 Humidity sensors; Humidity sensors are assigned within all en-suite bathrooms and the airing cupboard. Controls may wish to be extended also to Kitchen areas, or these may want to use a manual control. Such a measure allows the ventilation system to react automatically to changes in humidity levels through showering etc, without the need to manually increase the ventilation rate. The humidity controls increase the flow rate where the relative humidity within these zones increases. The signal is assigned to turn ON when the relative humidity within any zone is >45%. The flow rate is assigned to be zero where the relative humidity is <45% tending to full flow rate where the relative humidity is >65%, as follows: Fig 17.. Humidity Sensor Settings

20 CO2 Sensors A single CO2 sensor is allocated with the Entrance Hall area. This sensor regulates the flow rate dependent upon CO2 levels in the building. Such controls allow the MVHR unit to regulate the flow rate automatically dependent upon CO2 levels eg where there is a high occupancy rate at a party for example, the ventilation rate will increase to prevent the room from feeling stuffy. The signal is ON where CO2 levels exceed 1000ppm. The sensor regulates the flow rate from zero where CO2 levels are <1000ppm, tending to full ventilation where CO2 levels are >1500ppm, as follows: Fig 18.. CO2 Sensor Settings

21 Duct Mounted Heater Battery Control; A duct mounted heater battery is accounted for within the simulation. The heater battery is assigned to be regulated using a duct thermostat located within extract duct, at the point of entering the MVHR unit. The thermostat signal is ON when the internal temperature is <18 C, with a 2 degree dead band. The heater battery is assigned to provide full heating output at <18 C, tending to zero where the temperature within the duct is >20 C. The heater battery is sized to raise the incoming air temperature to a maximum of 24 C, as follows; Fig 19.. Duct Mounted Heater Battery Thermostatic Settings

22 Earth Tube Frost Protection Duct An earth tube has been accounted for within the simulation to model the frost protection aspects of the earth tube and the ability to condition air temperatures closer to room set-point temperatures through the year. The duct is modelled as a series of 200mm dia. 1m long sub-surface modular pipes, as shown below; An adjacent temperature condition has been assigned to the surface of the pipe using a temperature profile based on estimated soil temperatures at a 1m depth at the site, as shown below; Fig 20.. Air tube External Adjacency Temperature Profile Soil Temperature at 1m Depth Temp. (oc) Soil Temperature at 1m Depth Week

23 Within the Apache HVAC systems simulation interface, these ten sections of pipe are modelled as ten separate rooms through which the air supply to the MVHR unit must flow. As the air moves through the pipe at the flow rate required by the MVHR system, heat is extracted from the soil and into the supply air, raising or reducing the air supply temperature accordingly. The ten rooms running into the MVHR unit, as modelled within Apache HVAC are shown below: 23 Fig 21.. Air tube modelling within Apache HVAC

24 MVHR Summertime By-pass Damper Control A summer-time bypass damper is present within The PAUL Novus 300 MVHR unit. It is advised that whichever unit is selected, a by-pass damper should be present. The heat recovery matrix is assigned to provide a heat recovery efficiency of 93% when active. The heat recovery matrix by-pass damper is assigned to be regulated dependent upon the extract air temperature. Where the extract air is <22oC, the heat recovery unit is assigned to be active. The control gradually by-passes the heat recovery matrix as the temperature within the extract duct tends to 24 C; providing full by-pass for temperatures >24 C, as follows; Fig 22.. Summer-time heat Recovery By-pass Settings Note: The ventilation system description within this element of the report is intended to aid in the design of the system, but should not be considered a substitute for a complete system design. It is advised that an appropriate ventilation systems designer is appointed to undertake detailed design of the system, which may be used to inform future updates to the thermal simulation.

25 DHW Heating System DHW Demand Calculations The domestic hot water system is assigned to draw-off hot water from the thermal store located within the plant room (via a heat exchanger) at 60 C, serving taps within the en-suite bathrooms and kitchens. A secondary circulation circuit is not accounted for, owing to the additional thermal losses from such a system. For showers and hand basins, water is likely to be blended down to approx. 45 C at point of use. For washing-up and for baths a flow temperature of up to 65 C may be desired. The following estimations of hot water use have been used within the simulation; Showers; Baths; 8.5 lts/min - 5 minutes per shower 42.5ltrs per 45 C 29.75lts per C 165 ltrs (Max.) bath at 66.6% capacity 110ltrs in C 60 C Hand basins/sinks; 60 C over three periods during the day

26 26 The profile of hot water use is assigned as follows; Master Bedroom En-suite; Fig 23.. Tally of Showers/Baths in Master Bedroom Ensuite Day Number Showers Number Baths Mon 1 1 Tues 2 0 Weds 2 0 Thurs 1 1 Fri 1 1 Sat 2 0 Sun 1 1 Fig 24.. Master Ensuite Shower Day Profile Fig 25.. Master Ensuite Bath Day Profile

27 27 Bedroom 4 En-suite; Fig 26.. Tally of Showers/Baths in Bedroom 4 Ensuite Day Number Showers Number Baths Mon 2 0 Tues 2 0 Weds 2 0 Thurs 2 0 Fri 2 0 Sat 2 0 Sun 2 0 ; Fig 27.. Ensuite 4 Shower Day Profile

28 28 Bedroom 3 En-suite; Fig 28.. Tally of Showers/Baths in Bedroom 3 Ensuite Day Number Showers Number Baths Mon 1 0 Tues 1 0 Weds 1 0 Thurs 1 0 Fri 1 0 Sat 1 0 Sun 1 0 Hot water consumption within the Bedroom 3 en-suite is only assigned to be active outside of university term time, as follows; Fig 29.. Schedule of Occupied Periods in Bedroom 3 Ensuite Fig Fig Ensuite 3 Shower 3 Day Day Profile Profile Period Status Jan 1 Jan 4 Active Jan 4 Mar 27 Inactive Mar 27 Apr 26 Active Apr 26- Jun 17 Inactive Jun 17-Sept 28 Active Sept 28 Dec 12 Inactive Dec 12-Dec 31 Active

29 29 Guest Bedroom En-suite; Fig 31. Tally of Showers/Baths in Guest Bedroom Ensuite Day Number Showers Number Baths Mon 1 0 Tues 1 0 Weds 1 0 Thurs 1 0 Fri 1 0 Sat 1 0 Sun 1 0 Hot water consumption within the Guest Bedroom en-suite is only assigned to be active, during speculative periods, as follows; Fig 32.. Schedule of Occupied Periods in Guest Ensuite Fig 33.. Guest Ensuite Shower Day Profile Period Jan 1 Apr 15 Apr 15- Apr 18 Apr 18 Jul 20 Jul 20 Jul 25 Jul 25- Dec 23 Dec 23-Dec 28 Dec 28-Dec 31 Status Inactive Active Inactive Active Inactive Active Inactive

30 30 Hand basins/sinks; Hand basins and sinks have been assigned to use 16 ltrs of 60 C hot water at three separate intervals through each day. Depending on the amount that manual washing up etc is carried out, this speculative figure could be high or low and should be validated. Draw off is assigned at 09:00, 13:00 & 19:00. Fig 34.. Schedule of Hand basin/sink usage Totals; The total hot water consumption at 60 C sums 64,240 ltrs per year, or 176 ltrs per day on average. Hot water usage depends highly on the occupant s behaviour. Reduction in the number of baths taken, and/or water consumed by hand basins etc could reduce this figure. It may be considered to undertake a detailed audit of hot water consumption in order to more accurately access this figure. However, regardless of the figure arrived at, consumption will vary dependent upon occupancy numbers present; therefore any figure is only theoretical. The figures used within this report probably account for the upper end of expected DHW consumption. If Bedroom 4 is more regularly occupied however and more frequent use of the Guest Bedroom occurs, consumption may be greater.

31 DHW/Space Heating Plant The design intent for the heating system is to provide energy inputs from a roof mounted solar thermal array into a high capacity thermal store located in the plant room. The thermal store will receive supplementary inputs from an additional heat source to cover winter time demand. This additional heat source is at present understood to be a gas fired boiler, though this may be subject to change. From the thermal store, a LTHW radiator circuit shall serve radiators identified section of the report. It is suggested that this operates via a thermostatic blending valve to regulate the flow temperature to 45 C as discussed within Section of the report. Domestic hot water shall enter a heat exchanger at the top of the thermal store, extracting energy from the highest temperature water, before exiting the heat exchanger via a thermostatic blending valve set to C. The system assembly shall be similar to that pictured below (as modelled within T*Sol software); Fig 35. Schematic of single Store Solar System

32 Domestic hot water plant has been modelled within the IES Apache HVAC systems simulation interface. Doing so allows modelling to take place where by the solar thermal collectors are able to be accounted for within the space heating system, as required. The system assembly is shown below; 32 Fig 36.. Schematic of Heating System with ApacheHVAC The solar thermal collectors are modelled using the following parameters; Fig 37.. ApacheHVAC Solar Parameters

33 33 Of particular importance are; The collector area (modelled as 11.52m²) Azimuth (modelled at 180 ; due south) Tilt (modelled at 90 ) The conversion efficiency at ambient temperature (modelled at 65%) Panels should be selected with the highest conversion efficiency as available. The thermal store is assigned at 500ltrs capacity (though other capacities are assessed later within the report). Typical thermal losses from a store of this size have been accounted for. The system as modelled within the software does not completely mirror the assembly of the system in practice. Stratification is not modelled with the thermal store the store is calculated as a volume at a single temperature. In practice, this would not occur higher temperature water will migrate to the top of the cylinder and displace colder water to the bottom, a process known as stratification. Further, the system is modelled such that the tank is heated via the solar thermal system (at a single temperature stratification is not modelled). The DHW is taken from the cylinder (required at 60 C) and if of an insufficiently temperature, shall be heated via the gas boiler. As the average thermal store temperature sits around 45 C, the simulation accounts for top-up to 60 C through much of the year. This is not likely to occur in practice, as the top of the thermal store, from which DHW is extracted (via a heat exchanger), is likely to be up to 60 C via solar thermal heating inputs for much of the year. For this reason, the IES model has been used for space heating loads and a variety of further analysis which are independent from energy, however further analysis using T*Sol software, which does account for tank stratification, has been used for interrogation of the solar thermal system.

34 Internal Gains; Occupants, Lighting & Equipment Internal gains resulting from occupants, lighting and equipment have been modelled based on information provided by the client. As the principle purpose of this assessment is to assess the heating plant sizing for the building, equipment gains have not been accounted for, as these will displace heating demand. The following peak gains are associated with each room; Fig 38.. Peak Occupancy and Lighting Gains Room Lighting Equipment Occupants Power Schedule Power (W) Schedule (Nr) Schedule (W) -01 Reception 56 A 0-2 A -01 Bedroom 3 42 B 0-1 B -01 Bedroom 3 En-suite 21 C 0-1 C -01 Bedroom 4 42 D 0-2 D -01 Bedroom 4 En-suite 21 E 0-1 E -01 Corridor/Stair Airing Cup d Linen Cup d Plant Room Lobby 14 F Guest En-suite 21 G 0-1 G 00 Utility Kitchen 42 H 0-1 H 00 Study/Office 68 I 0-1 I 00 Cup d Guest Bedroom 42 J 0-2 J 00 Larder/Riser Cup d/riser Entrance Hall 42 F Kitchen 56 H 0-3* K 00 Dining 28 H 0-3* K 00 Main Reception 104 H 0-3* K 00 Entrance Lobby Master Bedroom 42 D 0-2 D 01 Master En-suite 21 E 0-1 E

35 Lighting Schedules The following variation profiles have been applied to lighting within each room (as indicated within fig.36 above). Lighting takes account of lesser use within the summer, using separate profiles for winter, spring/autumn &summer. Fig 39.. Lighting Schedules A; Reception Lighting Yr; Operation Annual Winter Autumn/Spring Summer B; Bedroom 3 Lighting Yr; Operation Restricted to Occupied Periods Only Winter Autumn/Spring Summer C; Bedroom 3 En-suite Lighting Yr; Operation Restricted to Occupied Periods Only Winter Autumn/Spring Summer

36 36 D; Master Bedroom/Bedroom 4 Lighting Yr; Operation Annual Winter Autumn/Spring Summer E; Master Bedroom En-suite/Bedroom 4 En-suite Lighting Yr; Operation Annual Winter Autumn/Spring Summer F-Circulation Areas Lighting; Operation Annual Winter Autumn/Spring Summer G- Guest En-suite Lighting Yr; Operation Restricted to Occupied Periods Winter Autumn/Spring Summer

37 37 H-Kitchen/Dining/Main Reception Lighting Yr; Operation Annual Winter Autumn/Spring Summer I- Study Lighting Yr; Operation Restricted to Mon, Tue, Weds, Fri Only Winter Autumn/Spring Summer J-Guest Bedroom Lighting Yr; Operation Restricted to Occupied Periods Winter Autumn/Spring Winter

38 Occupancy Schedules The following variation profiles have been applied to occupancy gains. These profiles tie-in with the profiles also used for lighting and DHW consumption, as follows; Fig 40.. Occupancy Schedules A; Reception Occ Yr; Occupation Annual Weekdays & Weekends - B; Bedroom 3 Occ Yr; Restricted to Occupied periods Defined in Fig. 29 Weekdays & Weekends - C; Bedroom 3 En-suite Occ Yr; Restricted to Occupied Periods Defined in Fig. 29 Weekdays & Weekends -

39 39 D; Master Bedroom/Bedroom 4 Occ Yr; Occupation Annual Weekdays & Weekends - E; Master Bedroom En-suite/Bedroom En-suite 4 Occ Yr; Occupation Annual Weekdays & Weekends - G-Guest En suite Occ Yr; Restricted to Occupied Periods Defined in Fig. 32 Weekdays & Weekends - H-Kitchen/Dining/Main Reception Occ Occupation Annual Weekdays & Weekends -

40 40 I- Study Occ Yr; Operation Restricted to Mon, Tue, Weds, Fri Only Mon, Tues, Weds, Fri Thurs, Sat, Sun Not Occupied J- Guest Bedroom Occ yr; Restricted to Occupied Periods Defined in Fig. 32 Weekdays & Weekends - K-Kitchen/Dining/Main Reception Occ Yr Days within periods defined within table X. Other days

41 Humidity Gains and CO2 Levels Humidity gains In order to simulate the effect of humidity gains as the consequence of showing, bathing and cooking, humidity gains have been added within the simulation based upon CIBSE Guide A guidance. Showering is accounted to add 0.001kg/s up to 100% humidity based upon DHW demand profiles within en-suites. Cooking accounts for the same levels of humidity based upon the Kitchen DHW use profile. Humidity gains do not represent a cooling effect through evaporation Vapour gains The effect of drying clothes within the airing cupboard has been accounted for. It is assumed that 3.Nr 24hr periods of clothes drying will occur per week, where external temperatures are <10 C kg/s of vapour are produced, based upon CIBSE Guide A data. Vapour gains do represent a cooling effect through evaporation.

42 Control of Windows & Doors Control of Windows; Windows which are identified to be opening windows are assigned to be opened to 10 when the external air temperature is >17 C. Windows are assigned to open gradually, being fully open when the external air temperature is >19 C. When the external air temperature exceeds 22 C windows are assigned to be shut. By automating MVHR controls, the ventilation system will automatically reduce the flow rate when windows are opened, unless windows remain open and the internal temperature rises. The cooling philosophy for the building is to shut windows when external temperatures exceed 22 C and provide cooler ventilation air via the earth tube. As such, it would be prudent to provide an indicator inside the house which indicates whether it is suitable to open or close windows. Internal doors are assigned to remain shut in most cases and remain open in the case of the utility kitchen and lobby. External doors are assigned to remain shut. All internal doors account for an air gap equal to 0.5% of the door area to allow the flow of ventilation between rooms. It is of high importance that this air gap is included. Louvered doors are accounted for on the speculative airing cupboard.

43 Simulation Results The building has been simulated based upon the parameters detailed within Section 2 of this report. It should be observed that occupancy templates used for DHW demand may be subject to change through variations in the building s occupancy levels and these results only provide an indicative impression of the actual scenarios. This initial assessment is based upon vertically orientated solar collectors covering 11.52m², with a 1500ltr thermal store. Further investigations into the performance of the building through changes to the specification are described with Section 4 of the report.

44 Study into Available Solar The design philosophy of the building is to utilise solar energy via evacuated tube solar thermal collectors and bank this energy using a thermal store, for use when required. As such, the solar energy which falls upon the roof of the build is of great importance, as this governs the quota of energy which is available for providing for space heating and DHW demand. Unless the thermal store is very large, where solar gains are less than space heating and DHW demand for weeks or months at a time, it is not possible to yield sufficient energy from the solar system to provide for demand. At such times, supplementary heating is necessary. A study has been conducted into the solar energy falling on the roof of the building, and that absorbed through the vertically inclined collectors. The solar energy on the roof is of interest as these calculations are independent from the calculations carried out to model the solar thermal system itself which within IES may not be fully representative. Section 3.02 assesses this energy in comparison to the space heating and DHW demand. The following images display solar gains on the building in terms of total energy yield for both clear sky days and diffuse sky (cloud cover) days;

45 45 Fig 41. Calculated solar gains on building exterior; Annual Clear Sky (kwh/m²) Fig. 42 Calculated solar gains on building exterior; Annual Diffuse Sky (kwh/m²) Fig.43 Calculated solar gains on building exterior; January Clear Sky (kwh/m²)

46 46 Fig. 44 Calculated solar gains on building exterior; January Diffuse Sky (kwh/m²) Fig. 45 Calculated solar gains on building exterior; July Clear Sky (kwh/m²) Fig. 46 Calculated solar gains on building exterior; July Diffuse Sky (kwh/m²)

47 Radiation flux upon the roof (W/m²) is shown in the table below. Note the distinctively different flux profiles through the year. The main roof receives lower radiation during Nov, Dec, Jan & Feb, but significantly higher yields through the rest of the year. The radiation flux on the vertical section of the roof achieves its highest peaks during the spring and autumn, with the summer flux achieving the lowest peaks through the year. This is due to the vertical plane being orientated more directly at the sun during the winter. 47 Fig 47.. Radiation Flux upon Roof Radiation flux upon the roof: Annual Radiation flux upon main roof (W/m²) Radiation flux (W/m²) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Date: Mon 01/Jan to Mon 31/Dec Radiation flux upon vertical element of (W/m²) Radiation flux (W/m²) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Date: Mon 01/Jan to Mon 31/Dec

48 The table and graph below display the available solar energy upon separate elements of the south facing roof; Fig 48. Table of Assessed Solar upon Roof Month Solar on Roof; Cloud Cover Mix -Based on Weather Template Solar & Power Solar & Power Solar & Power Upon South Facing Main Upon Vertical Element of Upon Entire South Roof South Facing Roof Facing Roof Solar Peak Solar gain (kw) Solar Peak Solar gain (kw) Solar Peak Solar gain (kw) Jan 2, , Feb 3, March , April 8, , May 9, , June 10, , July 9, , August 8, , September 7, , October 4, , November 2, , December 2, , Total 75,251.4 n/a 7,102.3 n/a 82,353.7 n/a 48 Fig 49.. Graph of Assessed Solar upon Roof 12, Available Solar on Roof 10, , , , , Vertical Roof Solar Main Roof Solar 0.00 Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec

49 Study into the Assessed Space Heating & DHW Demand The simulation has been used to assess the space heating loads within the building. The following results have been produced; Fig 50.. Table of Assessed Space Heating Demand Ventilation System Heating Total Rads Coil Date kwh kw peak kw mean kwh kw peak kw mean kwh kw peak kw mean Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec Annual Total The simulation has been used to assess the DHW loads within the building. The following results have been produced; Fig 51.. Table of Assessed DHW Demand DHW Demand Date kwh kw peak kw mean Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec Annual Total

50 50 The following results are achieved when both space heating demand and DHW demand are combined; Fig 52.. Table of Assessed Combined Space Heating and DHW Demand Space Heating Demand DHW Demand Space Heating and DHW Combined Demand Date kwh kwh kwh Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec Annual Total Fig 53.. Table of Assessed Combined Space Heating and DHW Demand 1600 Assessed Space Heating and DHW Demand 1400 kwh DHW Demand Space Heating Demand 0 Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec Month Conclusions: Aggregated across the year, when based on the modelled parameters, DHW represents an energy demand approximately 45% more than that of space heating. During the heating season, space heating demand reaches a maximum demand within a single month approximately 54% greater than the DHW demand.

51 3.3 Study into the relationship between Demand and Available Generation From section 3.01 and 3.02 of the report, we can conclude the following; 51 Fig 54.. Comparison of Combined Space and DHW Demand with Available Solar Gains on South Roof Conclusions: Space Heating and DHW Combined Demand Solar Upon Entire South Facing Roof Date Jan ,074.5 Feb Mar ,860 Apr ,164.7 May ,035.1 Jun ,823.4 Jul ,936 Aug ,714.8 Sept ,112.8 Oct ,586 Nov ,249.1 Dec ,780.4 Annual Total ,353.7 Sufficient solar energy falls upon the roof of the building within any single month to supply the energy demands calculated within the simulation. However, the efficiency of converting this energy into useful heat shall govern the ability of the building to operate using solar energy alone.

52 Assessing the Generation Available from Solar Technologies Due to the aforementioned limitations with solar thermal calculations conducted within IES, Valentin T*Sol software has been selected for detailed analysis of the solar thermal system. A system has been modelled accounting for 4Nr. IVT 18 CPC evacuated tube panels (as previously specified), at a vertical inclination, in combination with a 500ltr thermal store. The available yield from a PV array, measuring 5m x 10.6m has been calculated within IES, using the following parameters for the PV panel specification. Note that the array area indicated is for the total active area of the collectors; a reduction in the area should be applied where the panel frame reduces the collector area; Fig 55.. Parameters for PV Array Input into IES Simulation It is assumed that via the PV array will be fed into the thermal store via immersion heaters at 100% efficiency. The following results are calculated; Fig 56.. Total Generation through Solar Technologies as Calculated within IES of Solar System (calculated in T*Sol) of Solar PV System (calculated in IES) Total through Solar Technologies Date Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec Annual Total 3, , ,328.73

53 Assessing the Ability of Solar Technologies to Meet Assessed Heating Demands From sections 3.02 and 3.04 we can deduce that; Fig 57.. Total Generation through Solar Technologies as Calculated within IES Space Heating and DHW Combined Demand Total through Solar Technologies deficit/surplus Required by Supplement ary heat Source Date Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec Annual Total , , , Conclusions: Based on the parameters input into the assessments, it can be expected that based upon the proposed specification, the building shall be self-sufficient for space heating and DHW from April to October. This accounts for 4Nr IVT 18 CPC collectors, orientated vertically, a 1500ltr thermal store and 53m² of PV panels at a 30 inclination. Supplementary energy inputs will be required between November and March. The solar PV system will operate at a surplus during April-October, thus allowing export to the grid. The energy from both the solar technologies is calculated to provide 72% of the total annual space heating and DHW energy demand.

54 Study into Local Space Heating Demand The thermal simulation is assembled in order to provide a minimum internal temperature of +18 C. Based on simulation inputs described within Section 2 of the report, the following radiator and ventilation system heater battery peak heating loads have been calculated. It would be prudent to apply an over sizing factor (circa 20%) to these calculations. Also note that it is intended that the LTHW circuit shall run as 45 C, therefore all radiators should be oversized accordingly. Fig 58. Peak and Mean Space Heating Loads by Room as Calculated within IES Room Max. Output (kw) Max. Output Time Mean Output (kw) 00 Lobby :51,10/Jan Utility Kitchen :27,24/Oct Study/Office :09,11/Jan Guest Room :57,11/Jan Master Bedroom :21,11/Jan Bedroom :27,08/Jan Bedroom :45,02/Dec Reception :03,07/Jan Main Reception :33,09/Jan Ventilation System Heater Battery , 09/Jan 0.110

55 Study into Internal Temperatures Internal temperatures have been assessed within the simulation. The graph below indicates the internal temperatures within the building when simulated using the CIBSE Southampton Typical Reference Year 05 weather file. Fig Graph of Internal Temperatures using Southampton TRY weather file Temperature ( C) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Date: Mon 01/Jan to Mon 31/Dec Air temperature: 00 Lobby (HILLSIDE Vertical Panel Only U= ltr store.aps) Air temperature: 00 Guest Ensuite (HILLSIDE Vertical Panel Only U= ltr store.aps) Air temperature: 00 Utility Kitchen (HILLSIDE Vertical Panel Only U= ltr store.aps) Air temperature: 00 Study/Office (HILLSIDE Vertical Panel Only U= ltr store.aps) Air temperature: 00 Guest Room (HILLSIDE Vertical Panel Only U= ltr store.aps) Air temperature: 01 Master Bedroom (HILLSIDE Vertical Panel Only U= ltr store.aps) Air temperature: 00 Entrance Hall (HILLSIDE Vertical Panel Only U= ltr store.aps) Air temperature: 01 Master Ensuite (HILLSIDE Vertical Panel Only U= ltr store.aps) Air temperature: -01 Bedroom 3 (HILLSIDE Vertical Panel Only U= ltr store.aps) Air temperature: -01 Bedroom 3 Ensuite (HILLSIDE Vertical Panel Only U= ltr store.aps) Air temperature: -01 Bedroom 4 Ensuite (HILLSIDE Vertical Panel Only U= ltr store.aps) Air temperature: -01 Bedroom 4 (HILLSIDE Vertical Panel Only U= ltr store.aps) Air temperature: -01 Reception (HILLSIDE Vertical Panel Only U= ltr store.aps) Air temperature: -01 Corridor/Stair (HILLSIDE Vertical Panel Only U= ltr store.aps) Air temperature: 00 Kitchen (HILLSIDE Vertical Panel Only U= ltr store.aps) Air temperature: 00 Dining (HILLSIDE Vertical Panel Only U= ltr store.aps) Air temperature: 00 Main Reception (HILLSIDE Vertical Panel Only U= ltr store.aps) A second simulation has been run using the CIBSE Southampton Design Summer Year 05 weather file, which accounts for higher summer time temperatures. The following results are achieved; Fig Graph of Internal Temperatures using Southampton DSY weather file Temperature ( C) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Date: Mon 01/Jan to Mon 31/Dec Air temperature: 00 Lobby (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Air temperature: 00 Guest Ensuite (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Air temperature: 00 Utility Kitchen (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Air temperature: 00 Study/Office (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Air temperature: 00 Guest Room (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Air temperature: 01 Master Bedroom (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Air temperature: 00 Entrance Hall (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Air temperature: 01 Master Ensuite (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Air temperature: -01 Bedroom 3 (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Air temperature: -01 Bedroom 3 Ensuite (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Air temperature: -01 Bedroom 4 Ensuite (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Air temperature: -01 Bedroom 4 (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Air temperature: -01 Reception (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Air temperature: -01 Corridor/Stair (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Air temperature: 00 Kitchen (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Air temperature: 00 Dining (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Air temperature: 00 Main Reception (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Jan

56 56 Fig 61.. Table of Internal Temperatures using Southampton TRY weather file Room Occupied time <18 C (%) Occupied time >26 C (%) Occupied time >28 C (%) CIBSE Guide A compliant? 00 Lobby YES 00 Guest En-suite YES 00 Utility Kitchen YES 00 Study/Office YES 00 Guest Room YES 01 Master Bedroom YES 00 Entrance Hall YES 01 Master En-suite YES -01 Bedroom YES -01 Bedroom 3 En-suite YES -01 Bedroom 4 En-suite YES -01 Bedroom YES -01 Reception YES -01 Corridor/Stair YES 00 Kitchen YES 00 Dining YES 00 Main Reception YES Fig 62. Table of Internal Temperatures using Southampton DSY weather file Room Occupied time <18 C (%) Occupied time >26 C (%) Occupied time >28 C (%) CIBSE Guide A compliant? 00 Lobby YES 00 Guest En-suite YES 00 Utility Kitchen YES 00 Study/Office YES 00 Guest Room YES 01 Master Bedroom YES 00 Entrance Hall YES 01 Master En-suite YES -01 Bedroom YES -01 Bedroom 3 En-suite YES -01 Bedroom 4 En-suite YES -01 Bedroom YES -01 Reception YES -01 Corridor/Stair YES 00 Kitchen YES 00 Dining YES 00 Main Reception YES Conclusions: Based on the parameters input into the assessments, all areas will remain above 18 C for >99.5% of occupied time. So long as windows and doors are shut during periods where external air temperatures are >22 C, over heating is highly unlikely.

57 Study into the Performance of the Earth Tube and MVHR unit The PAUL Novus 300 MVHR will tolerate supply air temperatures of -8 C. Other MVHR units may not tolerate such conditions. The function of the earth tube is to provide frost protection to the MVHR unit, to avoid the risk of drawing air into the system which is too cold. It also provides the role of heating the incoming air supply to reduce heating demand, and also cooling the incoming air supply to provide space cooling via the ventilation system during the summer. The earth tube has been modelled as 10Nr 200mm dia. Chambers, through which the air supply to the MVHR unit is drawn. The graph below displays the air temperature as it passes through the duct, with the green line indicating the entry temperature and the blue line showing the exit temperature as it passes into the MVHR unit. Fig 63.. Graph of Entry and Exit Air Temperatures to Earth Tube (using DSY weather file) Temperature ( C) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Date: Mon 01/Jan to Mon 31/Dec Air temperature: ET Chamber 1 (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Air temperature: ET Chamber 10 (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Conclusions: An earth tube of 10m in length with a dia. Of 200mm will be sufficient to raise the incoming air temperature to not less than 3 C. A longer earth tube will be necessary if the MVHR unit cannot tolerate temperatures <3 C.

58 58 The flow rate through the MVHR unit is shown in the graph below; Fig 64.. Graph of Annual Mechanical Ventilation Flow Rates Volume flow (l/s) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Date: Mon 01/Jan to Mon 31/Dec Volume flow: layer 0/56 (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) The unit is assessed to utilise its full capacity throughout the year.

59 59 C02 levels within the building have been assessed. The following results are achieved; Fig 65.. Graph of Annual CO2 Levels by Room CO2 concentration (ppm) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Date: Mon 01/Jan to Mon 31/Dec Room CO2 concentration: 00 Lobby (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Room CO2 concentration: 00 Utility Kitchen (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Room CO2 concentration: 00 Guest Room (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Room CO2 concentration: 00 Entrance Hall (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Room CO2 concentration: -01 Bedroom 3 (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Room CO2 concentration: -01 Bedroom 4 Ensuite (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Room CO2 concentration: -01 Reception (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Room CO2 concentration: 00 Kitchen (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Room CO2 concentration: 00 Main Reception (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Room CO2 concentration: 00 Guest Ensuite (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Room CO2 concentration: 00 Study/Office (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Room CO2 concentration: 01 Master Bedroom (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Room CO2 concentration: 01 Master Ensuite (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Room CO2 concentration: -01 Bedroom 3 Ensuite (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Room CO2 concentration: -01 Bedroom 4 (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Room CO2 concentration: -01 Corridor/Stair (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Room CO2 concentration: 00 Dining (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) The following results are achieved within the Entrance Hall, in which the CO2 sensor is located; Fig 66.. Graph of Annual CO2 Levels within Entrance Hall CO2 concentration (ppm) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Date: Mon 01/Jan to Mon 31/Dec Room CO2 concentration: 00 Entrance Hall (HILLSIDE DSY Vertical Panel Only U= ltr store.aps)

60 60 Relative humidity has been assessed within the building. The following results are achieved; Fig 67.. Graph of Annual Relative Humidity Levels by Room Percentage (%) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Date: Mon 01/Jan to Mon 31/Dec Relative humidity: 00 Lobby (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Relative humidity: 00 Utility Kitchen (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Relative humidity: 00 Guest Room (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Relative humidity: 00 Entrance Hall (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Relative humidity: -01 Bedroom 3 (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Relative humidity: -01 Bedroom 4 Ensuite (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Relative humidity: -01 Reception (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Relative humidity: 00 Kitchen (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Relative humidity: 00 Main Reception (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Relative humidity: 00 Guest Ensuite (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Relative humidity: 00 Study/Office (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Relative humidity: 01 Master Bedroom (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Relative humidity: 01 Master Ensuite (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Relative humidity: -01 Bedroom 3 Ensuite (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Relative humidity: -01 Bedroom 4 (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Relative humidity: -01 Corridor/Stair (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Relative humidity: 00 Dining (HILLSIDE DSY Vertical Panel Only U= ltr store.aps) Results for both CO2 and relative humidity are tabulated below; Fig 68.. Table of Relative Humidity and CO2 Levels beyond Acceptable Limits Room Relative Humidity C02 Concentration Percentage of occupied time >65% Relative Humidity Percentage of occupied time >75% Relative Humidity Percentage of occupied time >1000ppm C02 Concentration Percentage of occupied time >1500ppm C02 Concentration 00 Lobby Guest En-suite Utility Kitchen Study/Office Guest Room Master Bedroom Entrance Hall Master En-suite Bedroom Bedroom 3 En-suite Bedroom 4 En-suite Bedroom Reception Corridor/Stair Kitchen Dining Reception

61 61 Conclusions: CO2 levels are shown to peak at periods where the house is fully occupied (6 people + 3 evening guests in Reception/Dining/Kitchen), however CO2 concentrations remain acceptable. High relative humidity levels occur within occupied areas such as the office/study and utility kitchen. The specification at present accounts for humidity sensors only within the en-suites and main kitchen. It is recommended that these are extended to include other occupied areas including the office/study, utility kitchen and lower ground floor reception. Of course, the ventilation system could run at a fixed rate with manual boost for periods of post showering/high occupancy, but this would result in higher thermal losses through the ventilation system, leading to higher heating demands.

62 Study into Suitable Sizing of the Store A principal element of the thermal simulation is to establish suitable sizing of the thermal store, used as part of the active solar heating system. The design philosophy is to utilise a thermal store, located within the plant room, to provide DHW at 60 + and to provide for space heating via a LTHW circuit at 45 C. In order to generate heat, 4Nr evacuated tube solar thermal collectors (specification TBC) shall be located on the roof of the building at a vertical inclination. These panels are optimised for winter time gains, with peak gains occurring within April and September as shown with Fig. 46. In addition, 53m² (TBC) of photovoltaic panels shall also be available for providing electrical power which can be used to operate immersion heaters located within the thermal stores. The efficiency of PV panels will be around 15-18%, compared to the solar thermal panels at around 65%. Therefore, the energy via PV, although significantly larger in area, is around the same as that of the solar thermal collectors. However, the PV collectors have the added benefit of exported excess energy to the national grid via a two way metre. The added benefit of utilising a large quota of PV generated energy within the heating system means that both the feed-in-tariff (FiT) and abundant local renewable can be made viable. In such an arrangement, the solar thermal system is design to be optimised for winter-time, but will continue to feed into the system annually. The PV system shall also contribute a substantial quota of energy inputs into the thermal store, but will be able to export energy to the grid during the summer months where there is limited demand. The two systems have different characteristics. The solar thermal system can efficiently produce low temperature water in volume. The immersion heaters, powered by the PV array are more ideally suited to creating high temperature water, ideal for DHW consumption. Recommendations are given in this regard at the end of this section of the report. In respect of the capacity of the thermal store specified, this is a factor of the DHW and space heating demands and the capacity and profile available. Higher capacity thermal stores contain a high thermal mass, which takes longer to heat and longer to cool, allowing fluctuations in demand and profiles to be more easily ironed out. The additional thermal capacity also allows energy inputs to be input into the store for a higher proportion of the year, since there is more capacity available. However, with additional capacity comes higher thermal losses, and lower temperatures, which may be too low for DHW use. As such, an optimum sized store is calculable based upon the demand and profiles. This section of the report utilises system modelling within T*Sol software, gleaning DHW and space heating demand profiles from the IES model previously described.

63 Investigation into the Relationship of Store Capacity and Auxiliary Inputs Based on Solar Inputs Alone The tables below show initial investigations into the relationship between the thermal store capacity and the auxiliary energy inputs necessary, on a month-by-month basis. This simulation accounts for 4Nr IVT 18 CPC evacuated tube collectors, inclined vertically and orientated due south. Space heating and DHW demand is inherited from the IES simulation. Auxiliary inputs are added via a Worcester Bosch Greenstar 12kW gas boiler.

64 64 The outcomes for various sizes of thermal store with 50mm insulation are shown below; Fig 69. Table of Solar Inputs and Auxiliary Heat Supply Generation for Stores with 50mm PUR Foam Insulation, Accounting Only for Solar Inputs (1) Store with 50mm PUR Insulation 100ltr store 200ltr store 300ltr store 400ltr store of Solar System of auxiliary energy supply of Solar System of auxiliary energy supply of Solar System of auxiliary energy supply of Solar System of auxiliary energy supply Date Jan , Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec Annual Total Fig 70.. Table of Solar Inputs and Auxiliary Heat Supply Generation for Stores with 50mm PUR Foam Insulation, Accounting Only for Solar Inputs (2) Store with 50mm PUR Insulation 500ltr store 750ltr store 500ltr store 1500ltr store of Solar System of auxiliary energy supply of Solar System of auxiliary energy supply of Solar System of auxiliary energy supply of Solar System of auxiliary energy supply Date Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec , , , ,064.9 Annual Total

65 65 Results are shown below for thermal stores with 50mm PUR insulation in graphical format; Fig 71.. Graphical Representation of Fig 64 & 65 Data by Month Solar and Auxiliary Inputs into Various Sizes of Store w/50mm PUR Insulation ltr Solar 100ltr Aux 200ltr Solar 200ltr Aux Input ltr Solar 300ltr Aux 400ltr Solar 400ltr Aux 500ltr Solar 500ltr Aux 750ltr Solar 0 Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec Month 750ltr Aux Fig 72.. Graphical Representation of Fig 64 & 65 using Annual Data Solar and Auxiliary Inputs into Store w/50mm PUR Insulation Input (Kwh)

66 66 Conclusions The graphs above demonstrate that an optimum thermal store capacity exists based upon the and demand profiles of the building. Where the thermal store is too small, higher auxiliary inputs are required, since the insufficient thermal mass of the store is unable to ride out fluctuations in demand and. Where the thermal store is too large however, thermal losses from the store and the lower temperatures inside the store also result in additional auxiliary inputs being required. When accounting only for the solar thermal system (not accounting for PV inputs), an optimum size of store with 50mm polyurethane insulation around 500ltrs.

67 Investigation into the Effect of Additional Insulation to the Store The same simulation has been run as described within Section 4.1 of the report, however rather than accounting for just 50mm of polyurethane insulation, this simulation accounts for 100mm polyurethane insulation, plus 200mm of retro-fitted Knauf DriTherm 32 insulation.

68 The outcomes for various sizes of thermal store which have been super-insulated with 100mm PUR foam + 200mm DriTherm 32 insulation are shown below; 68 Fig 73. Table of Solar Inputs and Auxiliary Heat Supply Generation for Stores with 100mm PUR Foam + 200mm DriTherm Insulation, Accounting Only for Solar Inputs (1) Store with 100mm PUR Insulation + 200mm Dritherm ltr store 200ltr store 300ltr store 400ltr store of Solar System of auxiliary energy supply of Solar System of auxiliary energy supply of Solar System of auxiliary energy supply of Solar System of auxiliary energy supply Date Jan , Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec Annual Total Fig 74. Table of Solar Inputs and Auxiliary Heat Supply Generation for Stores with 100mm PUR Foam + 200mm DriTherm Insulation, Accounting Only for Solar Inputs (2) Store with 100mm PUR Insulation + 200mm Dritherm ltr store 750ltr store 1000ltr store 1500ltr store of Solar System of auxiliary energy supply of Solar System of auxiliary energy supply of Solar System of auxiliary energy supply of Solar System of auxiliary energy supply Date Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec Annual Total

69 Results are shown below for thermal stores with 100mm PUR insulation + 200mm DriTherm 32 in graphical format; Fig 75.. Graphical Representation of Fig 68 & 69 Data by Month Solar and Auxiliary Inputs into Various Sizes of Store w/100mm PUR insulation +200mm Dritherm 32 (Kwh) 69 Input Month 100ltr Solar 100ltr Aux 200ltr Solar 200ltr Aux 300ltr Solar 300ltr Aux 400ltr Solar 400ltr Aux 500ltr Solar 500ltr Aux 750ltr Solar 750ltr Aux 1000ltr Solar 1000ltr Aux 1500ltr Solar 1500ltr Aux Fig 76.. Graphical Representation of Fig 68 & 69 using Annual Data Solar and Auxiliary Inputs into Store w/100mm PUR Insulation + 200mm DriTherm 32 Input (Kwh)

70 70 Conclusions The graphs above demonstrate that where a well insulated thermal store with 100mm PUR foam insulation is super-insulated using Knauf DriTherm 32 (or similar), further reductions in auxiliary inputs can be made. When accounting only for the solar thermal system (not accounting for PV inputs), an optimum size of store with 100mm polyurethane insulation + 200mm retro-fitted Knauf DriTherm 32 is around 750ltrs. The auxiliary energy inputs may be reduced by approximately 8% where additional insulation is included.

71 4.3 Investigation into the Inclusion of Photovoltaic Array Inputs via Immersion Heaters The vertically orientated solar thermal collectors are of course not the only energy inputs into the thermal store. In addition, contributions from the PV array are also made via immersion heaters located in the thermal store. The T*Sol simulation software is intended for the modelling of solar thermal systems only, and does not have the capacity to account for such a mechanism. As such, additional inputs via the PV array have been modelled as a solar thermal array of 53m², accounting for an efficiency of only 18% (as per the PV collector efficiency). This array is inclined at 30 and orientated due south. Through this approach, the simulated data is more approximate than previous simulations described within the report. The diagram below displays the system layout accounted for, with two collector loops being accounted for; 71 Fig 77. System Schematic of two Collector Array System within T*Sol Software

72 72 The outcomes for various sizes of thermal store with 50mm insulation are shown below; Fig 78.. Table of Solar Inputs and Auxiliary Heat Supply Generation for Stores with 50mm PUR Foam Insulation, Accounting for both Solar and Estimated Solar PV Inputs (1) 100ltr store of Solar of auxiliary energy System supply Store with 50mm PUR Insulation 200ltr store 300ltr store of Solar System of auxiliary energy supply of Solar System of auxiliary energy supply 400ltr store of Solar of auxiliary energy System supply Date Annual Total Fig 79.. Table of Solar Inputs and Auxiliary Heat Supply Generation for Stores with 50mm PUR Foam Insulation, Accounting for both Solar and Estimated Solar PV Inputs (2) Store with 50mm PUR Insulation 500ltr store 750ltr store 1000ltr store 1500ltr store of Solar System of auxiliary energy supply of Solar System of auxiliary energy supply of Solar System of auxiliary energy supply of Solar System of auxiliary energy supply Date Annual Total Fig 80.. Table of Solar Inputs and Auxiliary Heat Supply Generation for Stores with 50mm PUR Foam Insulation, Accounting for both Solar and Estimated Solar PV Inputs (3) 2000ltr store of Solar of auxiliary energy System supply Store with 50mm PUR Insulation 2500ltr store 3000ltr store of Solar System of auxiliary energy supply of Solar System of auxiliary energy supply 4000ltr store of Solar of auxiliary energy System supply Date Annual Total

73 73 Fig 81.. Graphical Representation of Fig 73, 74 & 65 using Annual Data 6000 Solar and Auxiliary Inputs into Store w/50mm PUR Insulation, Accounting for Both Solar & Solar PV Inputs 5000 Input (Kwh) mm 100ltr solar 50mm 100ltr Aux 50mm 200ltr solar 50mm 200ltr Aux 50mm 300ltr solar 50mm 300ltr Aux 50mm 400ltr solar 50mm 400ltr Aux 50mm 500ltr solar 50mm 500ltr Aux 50mm 750ltr solar 50mm 750ltr Aux 50mm 1000ltr solar 50mm 1000ltr Aux 50mm 1500ltr solar 50mm 1500ltr Aux 50mm 2000ltr solar 50mm 2000ltr Aux 50mm 2500ltr solar 50mm 2500ltr Aux 50mm 3000ltr solar 50mm 3000ltr Aux 50mm 4000ltr solar 50mm 4000ltr Aux

74 The outcomes for various sizes of thermal store which have been super-insulated with 100mm PUR foam + 200mm DriTherm 32 insulation are shown below; Fig 82.. Table of Solar Inputs and Auxiliary Heat Supply Generation for Stores with 100mm PUR Foam +200mm DriTherm Insulation, Accounting for both Solar and Estimated Solar PV Inputs (1) 74 Store with 100mm PUR Insulation + 200mm Dritherm ltr store 200ltr store 300ltr store 400ltr store of Solar System of auxiliary energy supply of Solar System of auxiliary energy supply of Solar System of auxiliary energy supply of Solar System of auxiliary energy supply Date Annual Total Fig 83.. Table of Solar Inputs and Auxiliary Heat Supply Generation for Stores with 100mm PUR Foam +200mm DriTherm Insulation, Accounting for both Solar and Estimated Solar PV Inputs (2) Store with 100mm PUR Insulation + 200mm Dritherm ltr store 750ltr store 1000ltr store 1500ltr store of Solar System of auxiliary energy supply of Solar System of auxiliary energy supply of Solar System of auxiliary energy supply of Solar System of auxiliary energy supply Date Annual Total Fig 84.. Table of Solar Inputs and Auxiliary Heat Supply Generation for Stores with 100mm PUR Foam +200mm DriTherm Insulation, Accounting for both Solar and Estimated Solar PV Inputs (3) Store with 100mm PUR Insulation + 200mm Dritherm ltr store 2500ltr store 3000ltr store 4000ltr store of Solar System of auxiliary energy supply of Solar System of auxiliary energy supply of Solar System of auxiliary energy supply of Solar System of auxiliary energy supply Date Annual Total

75 75 Fig 85.. Graphical Representation of Fig 77, 78 & 79 using Annual Data Input (Kwh) Solar and Auxiliary Inputs into Store w/100mm PUR Insulation + 200mm DriTherm 32, Accounting for Both Solar & Solar PV Inputs 300mm 100ltr solar 300mm 100ltr Aux 300mm 200ltr solar 300mm 200ltr Aux 300mm 300ltr solar 300mm 300ltr Aux 300mm 400ltr solar 300mm 400ltr Aux 300mm 500ltr solar 300mm 500ltr Aux 300mm 750ltr solar 300mm 750ltr Aux 300m 1000ltr solar 300mm 1000ltr Aux 300mm 1500ltr solar 300mm 1500ltr Aux 300mm 2000ltr solar 300mm 2000ltr Aux 300mm 2500ltr solar 300mm 2500ltr Aux 300m 3000ltr solar 300mm 3000ltr Aux 300mm 4000ltr solar 300mm 4000ltr Aux Results are shown graphically below for in order of performance for all system configurations; Fig 86.. Graphical of Auxiliary Inputs for all Store Combinations Auxiliary Inputs Store/Annum Auxiliary Inputs into Store for Various Capacities of Store and Insulation Thickness 50mm 100ltr Aux 300mm 100ltr Aux 50mm 200ltr Aux 300mm 200ltr Aux 50mm 300ltr Aux 300mm 300ltr Aux 50mm 400ltr Aux 50mm 500ltr Aux 300mm 400ltr Aux 50mm 4000ltr Aux 50mm 750ltr Aux 300mm 500ltr Aux 50mm 3000ltr Aux 50mm 1000ltr Aux 50mm 1500ltr Aux 50mm 2000ltr Aux 50mm 2500ltr Aux 300mm 750ltr Aux 300mm 1000ltr Aux 300mm 1500ltr Aux 300mm 2000ltr Aux 300mm 2500ltr Aux 300mm 3000ltr Aux 300mm 4000ltr Aux Insulation Thickness & Store Capacity Auxiliary Inputs into Store for Various Capacities of Store and Insulation Thickness

76 76 Conclusions The graphs and tables above demonstrate that for the space heating and DHW demand profiles present, and the profiles available from the solar collectors proposed, the optimum store will be a super-insulated store with retro-fitted insulation of 4000ltrs in capacity. However, only negligible impact will be had upon the auxiliary energy demand where a store of 1500ltrs or 2000ltrs is specified. If a thermal store with only 50mm insulation is selected, the optimum size will be around ltrs. Based on approximation, a thermal store with 100mm polyurethane insulation alone will be around ltrs. In broad terms, the most suitable selection will be a store with 100mm factory fitted polyurethane insulation of 1500ltrs in capacity; eg the Akvaterm 1500ltr solar store; Through the addition of further insulation, additional efficiency savings can be made.

77 Investigation into the Effect of a Dual Store System Hot water is required for two distinctly different purposes. LTHW for the space heating circuit is required in abundance at around 45 C, though temperatures above or below this temperature are tolerable. DHW on the other hand is required at C, and any temperature below this level will result in additional energy inputs from an auxiliary system. During the winter months, on certain days the system may struggle to reach 60 C, and instead the system will consist of a large volume of low temperature water (circa 45 C), which is suitable for space heating but not for DHW heating. One option to avoid this dilemma is to specify a dual cylinder system, where by a low capacity cylinder is provided for DHW and high capacity thermal store is provided for space heating storage/buffering. The beauty of this arrangement is that the two thermal stores used for separate purposes are kept completely isolated. The low capacity, low thermal mass cylinder for DHW provision reaches a high temperature quickly, whilst the high capacity, high thermal mass thermal store rides out fluctuations in space heating demand and, maintaining suitably low temperatures. The system has been modelled within T*Sol, as shown below; Fig 87. Schematic of Dual Cylinder System within T*Sol