Zeroth Energy System. Presenter. Date

Transcription

1 Zeroth Energy System Presenter Date

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3 Overview Review of overheating in UK homes Review of heat network performance Introduction to the Zeroth concept Key benefits

4 What is a heat pump? Heat Pump - Noun (Google) A device that transfers heat from a colder area to a hotter area by using mechanical energy, as in a refrigerator. Five key refrigeration components make up a vapour compression cycle: Refrigerant Evaporator energy collector (Cooling) Compressor increases pressure Condenser energy delivery (Heating) Expansion valve reduces pressure Types of Heat Pump Air Source Ground Source Water-Water

5 Building Overheating - Review Recognising overheating as a problem Identifying the causes of overheating Assessing and defining overheating

6 Reducing the risk UK location Occupant density Outdoor temperature Factors Affecting Overheating Time of day GLA Cooling Hierarchy 1. Minimise internal heat generation 2. Reduce summer heat entering the building (solar) 3. Use thermal mass 4. Passive Ventilation 5. Mechanical Ventilation 6. Mechanical cooling from the lowest carbon options Ventilation strategy Floor area Direction of glazing Ventilation strategy Internal Heat Gains Cooking People Lighting Household equipment Building Services

7 kwh per dwelling First Principles Analysis Heat Networks Network Losses Heat Consumed Efficiency 90% 80% 70% % % 40% % % 10% Part L NZEB Energy Neutral Efficiency of Buildings Boiler/CHP system with power KW losses of 10% actually have a theoretical maximum energy efficiency of 60%. 50% for NZEB 0%

8 Real Performance of Heat Networks with HIU s 3 kwh produced for every 1 kwh consumed at the apartment. i.e 33% network efficiency 1/2 kwh consumed NZEB Part L 2/3 kwh consumed Data from measured sites with Heat Networks Published by BRE SAP consultation 2016

9 Linking heat networks with overheating One Brighton post occupancy study suggests 300W per apartment Technology Strategy Board, 2014) (Source: HIU manufactures quote between W ISO Calculates heat loss from pipework suggests Watts per apartment at 70/40 or 80/70 For 40/60mm insulation on 880m network with 55 apartments But this assumes a perfect installation, no exposed valve bodies, no pipe clips, no gaps etc. So 300W is probably a fair representation We can eliminate this risk factor using a different type of distribution

10 The Zeroth Energy System Heat/Cool emitters with end user controls

11 Design Flexibility Emitter Options Radiator UFH Heating only (35-55⁰C) Smart Rad (Fan Convector) Fan Coil Heating and Cooling (7-18⁰C)

12 The Zeroth Energy System Heat Pump and Cylinder in each apartment

13 Apartment Heat Pump Cold water in Hot water out Water Loop Flow Water Loop Return Cylinder T&P valve Space Heating/Cooling Flow Space Heating/Cooling Return User Controls Adjustable Feet Servicing from the front Pre-plumbed and pre-wired

14 The Zeroth Energy System Heat Pump and Cylinder in each commercial space 3 5

15 Design Flexibility Emitter Options Chilled Beams UFH Heating only (35-55⁰C) Smart Rad (Fan Convector) Fan Coil Heating and Cooling (7-18⁰C)

16 The Zeroth Energy System Energy loop within building circulated at C 5

17 The Zeroth Energy System Heating and Cooling plant

18 The Zeroth Energy System Heat/Cool emitters with end user controls 2. Heat Pump and Cylinder in each apartment Heat Pump and Cylinder in each commercial space 3 4. Energy loop within building circulated at C 5 5. Heating and Cooling plant

19 Heat Network Performance Heat loss from pipework reduced by 90% with Zeroth

20 Summer Overheating Analysis - Corridors CHP/Boiler Summer No ventilation CHP/Boiler Summer Standard ventilation CHP/Boiler Summer Purge ventilation Zeroth No Ventilation

21 Energy Sharing Opportunities Winter DHW and Heating Summer DHW and Cooling Shoulder Months DHW, Heating and Cooling Where heating and cooling loads appear simultaneously, opportunities exist to save energy. But it is only possible with heat pump technology. GLA Cooling Hierarchy 1. Minimise internal heat generation 2. Reduce summer heat entering the building (solar) 3. Use thermal mass 4. Passive Ventilation 5. Mechanical Ventilation 6. Mechanical cooling from the lowest carbon options

22 DHW and cooling energy recovery 1. Compressor 2. DHW Condenser 3. DHW Cylinder 4. Reversing Valve 5. Condenser Heat Rejection 6. Expansion Valve 7. Evaporator 8. Apartment Emitters Cooling Heating

23 Project Analysis Example Exercise 125 apartments (32 x studio, 45 x 1 bed, 45 x 2 bed, 3 x 3 bed) London location Small amount of commercial space Heating and Cooling to each apartment Heat Interface Units and Chilled Water Interface Units Boiler, CHP and Air Cooled Chiller NZEB build specification (35% below Part L) Basement Plantroom SAP kwh s Typical riser: LTHW CHW MCWS

24 Project Analysis Example Exercise Stats Carbon tax of 109,106 or 873 per apartment ESCO cost per kwh thermal produced Tenant Running Cost per annum Carbon Tax Gas bought by ESCO Electric bought by ESCO ESCO sold heat ESCO sold Cold Standing Charge ESCO Modelling Assumptions 1800 per tonne CO per kwh 0.10 per kwh 0.07 per kwh 0.12 per kwh 0.50 per day

25 Changes Swap out HIU s for ZHP s Typical Apartment Services Soil Stack MVHR Heat Pump and Cylinder Combi 550 x 550mm footprint allows installation into a standard kitchen cabinet Electricals Washing Machine 1650 x 840 x 2400mm external dimension

26 Typical Plant Services Changes Reversible Heat Pumps with SCOP of 340% Zeroth System Efficiency of 300% Change from 4 pipe to 2 pipe network Heat Pump plant located outside the building Revised insulation specification Typical Zeroth riser: Loop MCWS

27 Project Analysis Example Exercise Zeroth Previous Design % Reduction Cost per kwh thermal % Tenant running cost per annum % Carbon Tax Payment 475 per apartment 873 per apartment Riser space increased Yes No 40-50% Plantroom space decreased Yes No Approx 50% Capex Saving 2085 per apartment 45% 0 N/A

28 Holistic Cost Considerations Carbon Tax Saving +ve Cost Saving +ve Cost Addition -ve Product cost -ve Additional Benefits +ve Zeroth Solution

29 Building Performance with Zeroth The key benefits of adopting Zeroth are: Significantly reduced overheating risk of apartments Significantly reduced corridor temperatures Significantly improved energy performance, lower resident bills Improved building services coordination Greater design flexibility for plant Opportunities to increase usable space Carbon tax saving opportunities Cost saving opportunities

30 Zeroth Product Specifications 4 and 6 kw Heating only 4 and 6 kw Heating and Cooling 180L unvented cylinder, up to 300L option available 550 x 550 x 2000mm (W/D/H) Available from Oct 2017

31 Zeroth Energy System Thank you for coming