A Guide to Commercial Hot Water from Hamworthy. Introducing Hamworthy s Product Ranges for Hot Water Generation:

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1 A Guide to Commercial Hot Water from Hamworthy Introducing Hamworthy s Product Ranges for Hot Water Generation: Dorchester Direct-Fired Water Heaters Powerstock Indirect-Fired Calorifiers and Tanks Solar Hot Water Systems With guidance on hot water issues for a successful system implementation

2 A Guide to Hot Water from Hamworthy Contents Overview Talk to Hamworthy Direct and Indirect Solutions Dorchester Water Heaters Introduction Dorchester Specification Dorchester DR-FC Evo Dorchester DR-TC Dorchester DR-LA/LP Dorchester DR-RS Dorchester DR-PF Dorchester DR-SA/SE Dorchester Options Range & Model Comparisons Powerstock Calorifiers & Tanks.. 15 Introduction Powerstock Calorifiers Powerstock Storage Tanks Powerstock Options Trigon Solar & Dorchester DR-TC. 18 Solar Hot Water Solutions Solar Systems Block Diagram Hot Water Information General Information Regulatory Information Sizing and Hamworthy Services Overview Hamworthy offer a comprehensive range of Natural gas, LPG, Oil, and solar powered solutions for the safe production of domestic hot water in commercial applications. These include Dorchester direct-fired water heaters, Powerstock calorifiers, and Dorchester DR-TC and Trigon solar hot water solutions. This guide presents an overview of Hamworthy products for DHW (Domestic Hot Water) generation, covering single units with maximum power ranging from 18kW to 144kW, and maximum continuous output ranging from 370 litres/hour to 3250 litres/hour. The guide also highlights some important issues associated with the production of potable domestic hot water that should be considered when specifying a commercial hot water system. For more detailed technical information, refer to the sales brochure specific to each range which is available to download from: or on request from your area sales representative. Contact Hamworthy sales Tel: sales@hamworthy-heating.com Talk to Hamworthy With such a wide choice of products available from Hamworthy, and with more than one potential solution to your DHW application, we always recommend that you discuss your requirements with our sales engineers. With their extensive experience of commercial DHW systems and in-depth knowledge of Hamworthy products, they will be able to help you focus in on solutions that best fit your requirements; ultimately guiding you to the most appropriate solution, whatever your selection criteria and application needs. Let Hamworthy help you make the right choice. Dorchester DR-FC Evo Fully Automatic Condensing, Direct- Fired Water Heaters The most versatile water heater from Hamworthy offering superior controls, excellent seasonal efficiencies up to 107% net and a wide range of room sealed and open flue options. 7 models Continuous outputs l/h Reduced energy costs Low noise Can be installed close to the point of use Dorchester DR-TC Solar Fully Automatic Solar Water Heaters with Integral Direct-Fired Condensing Gas Burner The innovative Dorchester DR-TC combines the use of solar energy with condensing gas fired capability using an intelligent control system. 2 heater models 2 solar transfer stations Continuous outputs l/h Saves space Prioritises solar energy over gas Dorchester DR-LA/LP Fully Automatic Multi-Tube Direct-Fired Water Heaters A natural replacement for existing water heaters, the Dorchester DR-LA is compatible with most existing flue designs and comes with a choice of flue connection positions. 13 models Continuous outputs l/h Permanent pilot option (DR-LP) Simplifies installation in replacement projects Horizontal or vertical flue connection Dorchester DR-RS Room Sealed, Fully Automatic Direct-Fired Water Heaters Dedicated room sealed water heater range with multi-tube heat exchanger. 5 models Continuous outputs l/h Ideal for plant rooms with restricted ventilation or locations without a plant room 2

3 Direct and Indirect Solutions Direct-Fired and Indirect-Fired Dorchester water heaters are direct-fired units, meaning each has an integral gas or oil burner that directly heats the water in its storage cylinder by supplying hot gases through one or more heat exchanger fire tubes within the cylinder which then transfers heat to the surrounding water. Conversely, Powerstock calorifiers, which have no integral burner, are indirect-fired units. Essentially they are storage water cylinders with single or twin heat exchanger coils. Each heat exchanger coil is then connected in a closed circuit with an external heating source such as a boiler, or solar collectors in solar circuit. The fluid is heated by the external source and pumped through the calorifier heat exchanger where it gives up heat to the stored water. As the stored water in calorifiers is indirectly heated by the external energy source (via the liquid heated directly by that source) calorifiers are referred to indirect-fired units. Dorchester Direct-Fired Solutions There are significant efficiencies to be gained by using a correctly sized, self-contained, direct-fired DHW system which is independent of the main building heating system, particularly if the application allows the heating boilers to be switched off during the summer months. Similarly, energy can be saved by installing a direct fired water heater close to the point of use, reducing the energy that is wasted over a long pipe run from a distant heat source. Hamworthy offer an impressive 37 Dorchester directfired water heaters across 8 different ranges and 3 fuel types to cover the varied needs and priorities of specifiers and contractors, whatever their project s DHW demand profile and product selection criteria. Powerstock Indirect-Fired Solutions Preference may be to have a DHW system powered via the boiler heating system and/or via solar circuit, and not to have an additional gas-fired appliance at all. In this case, Hamworthy can offer a range of 7 Powerstock calorifiers for an indirect-fired hot water storage solution. Powerstock calorifiers are the obvious choice if the direct-fired solution is not a feasible option e.g. flue cannot be installed in the proposed building. Powerstock calorifiers are available with single or twin coil heat exchangers. Twin-coil calorifiers allow the use of two independent heating sources, such as two gas boilers, or a gas boiler together with a biomass boiler or solar circuit. This adds both versatility and options for security of fuel supply, as well as the potential to introduce a proportion of heating via renewable means with the associated environmental and financial benefits. In addition all Powerstock calorifiers can also be directly electrically heated if fitted with an optional immersion heater. Extending Storage Capacity with Powerstock Tanks Hot water storage volumes for both direct-fired and indirectfired solutions can be augmented efficiently by the use of one or more highly insulated Powerstock storage tanks. There are 4 Powerstock storage tank models available ranging in capacity from 300 litres to 990 litres. Trigon and Dorchester DR-TC Renewable Solutions Hamworthy also offer the Trigon solar thermal hot water system product range in addition to the Dorchester DR-TC solar water heater for fully integrated renewable solutions to hot water generation. Dorchester DR-PF Power Flame, Gas or Oil, Direct-Fired Water Heaters Featuring a power flame burner the Dorchester DR-PF offers the highest outputs and is the only water heater that can use oil, natural gas or LPG. 6 models Continuous outputs l/h Greater flexibility with smaller flue diameter requirements Choice of fuel supply Dorchester DR-SA/SE Fully Automatic Single- Tube Direct-Fired Water Heaters The lowest output water heaters in the Dorchester range, these are ideal for smaller applications. 4 models Continuous outputs l/h Permanent pilot option (DR-SE) Ultra quiet operation DR-SE can operate without an electrical supply Powerstock Indirect-Fired Heating and Hot Water Storage Offering a flexible approach to indirect heating and storage. Powerstock calorifiers and storage tanks can be easily coupled to any heating boiler or renewable energy source to provide highly efficient hot water generation. Calorifiers 7 models Continuous outputs l/h Capacities l Trigon Solar Solar Thermal Hot Water System A complete package, which delivers everything required for an integrated solar hot water solution. Vertical or horizontal collectors On-roof or A-frame installation Standard or advanced controls Integrates with Dorchester water heaters or Powerstock calorifiers Storage Tanks 4 models Capacities l 3

4 Dorchester Water Heaters Introduction Dorchester products range from 18.9kW to 144.1kW and offer continuous outputs from 370 litres/hour to 3250 litres/hour respectively, with operating efficiencies up to 107% net. Dorchester direct-fired water heaters are designed to operate typically at up to 80 C and at pressures up to 8. The Dorchester range extends from traditional atmospheric direct-fired water heaters with relatively simple on/off thermostat controls right through to advanced timer-controlled high-efficiency (107% gross) condensing water heaters such as the Dorchester DR-FC Evo and the Dorchester DR-TC. The Dorchester DR-TC is a combined solar and gas-fired solution which can take advantage of nominally free solar energy in place of gas heating whenever the temperature at its solar collectors is just a few degrees above that of its stored water. It comes with integrated solar controls and a solar transfer station with solar pump. All Dorchester models require an appropriate flue and so the flue specification can be a key factor in deciding which Dorchester range is the most suitable for a particular application. If no flueing solution is feasible, then alternative solutions such as indirect-fired Powerstock calorifiers must be considered. Hot water strategies and application constraints can result in the need for a modular approach where there may be more than one Dorchester water heater, and a complete system may include Powerstock calorifiers, additional storage tanks and solar thermal or other heating systems. Having more than one heating source allows for easier maintenance without loss of service. Alternatively, the load profile might be such that additional or alternative heating sources are only brought into service at certain times to satisfy peak load requirements. There are many benefits to be gained by the incorporation of renewable energy systems into commercial hot water systems. The Dorchester DR-TC water heater addresses this directly with its integrated solar function. Similarly, Dorchester direct-fired water heaters can be supplied with a solar pre-heated cold water feed, using a Hamworthy Trigon solar system. Renewable solutions attract a range of financial incentives to encourage their take-up, as well as offering immediate savings in fossil fuel usage. A modular approach is used in the example below, in which the DHW system combines a indirect-fired solution with a direct-fired solution, with additional buffering at both stages. A combined Powerstock calorifier and Powerstock tank is heated by an external heat source (typically by a solar circuit, but in this case by an air sourced heat pump), and act together as a thermal store to provide a preheated cold water feed to the Dorchester DR-FC Evo direct-fired condensing water heaters. These water heaters are sequenced to operate alternately. Each water heater is fitted with an optional top-to-bottom recirculation kit, and also an optional unvented kit (with re-sized expansion vessel and a safety pressure-and-temperature relief valve). The water heaters are also coupled to another storage tank (not shown) to increase the overall DHW volume to meet the demand requirements of the application. A commercial Domestic Hot Water (DHW) plant featuring a Powerstock calorifier (left) with adjacent Powerstock storage tank providing preheated water for input to two Dorchester DR-FC Evo 25 water heaters each fitted with top-to-bottom recirculation kit and unvented kit options. 4

5 Dorchester Water Heaters Specification Construction All Dorchester ranges are built to last using high quality steel tanks and heat exchangers. For the safe production of potable hot water, a high quality vitreous enamel glaze is baked on to all tank interior and heat exchanger surfaces, creating a hygienic surface finish which gives excellent protection against corrosion. Additional corrosion protection is provided by either electrical anode protection or sacrificial magnesium anode systems, depending on the range type, and options selected. Access doors are provided for inspection and cleaning of internal surfaces, and all units are supplied fully insulated with CFC-free foam to minimise standing losses. Burners The Dorchester atmospheric water heater ranges: DR-LA/LP, DR- SA/SE, DR-RS, and Dorchester power flame DR-PF range, have burners at the base of the hot water cylinder and are up-firing. The Dorchester condensing water heater ranges: DR-FC Evo and DR-TC, have fan-blown down-firing pre-mix burners mounted at the top of the hot water cylinder. Heat Exchangers In the down-firing condensing water heater ranges (Dorchester DR-FC Evo and DR-TC), the single heat exchanger has a lengthy fire tube which first descends then rises and then descends again as a spiral coil before exiting the tank via a rising flue at the side of the tank. As the flue gases pass through the fire tube, they give up heat to the surrounding water, and consequently cool down as they pass through the tube to the flue. This type of heat exchanger is designed to maximise heat transfer but also to encourage the flue gases to cool sufficiently to cause some gases to condense, and so change state from a gas to a liquid. This change of state releases energy (latent heat) in the process which further heats the stored water, maximising the energy transferred and raising the overall efficiency of the water heater. Any condensate formed in this process is released via a condensate trap. This design of heat exchanger inhibits problems with scale as any build up will fall away to the base of the unit and not affect heat transfer or create hot spots. In the Dorchester DR-RS, DR-LA/LP and DR-PF up-firing burner ranges, multiple vertical fire tubes are arranged through the centre of the cylinder in the. Each fire tube is fitted with a flue baffle to maximise heat transfer and increase operational efficiency. The up-firing Dorchester DR-SA/SE ranges use a baffled single vertical fire tube flue. Designed for Safety Dorchester water heaters conform to HSC Approved Code of Practice and Guidance Document L8 for minimising the risk of Legionella, with design features such as: Good access for cleaning Generous flow and return connections Adequately sized drain Base designed to avoid sludge traps Anodes to inhibit metal corrosion Number of tappings correctly positioned to facilitate recirculation, destratification and to obviate stagnation areas Designed to meet unvented supply requirements In the DR-FC Evo and DR-TC models, specific anti-legionella cycles can be programmed to run automatically. For more information on Legionella and its prevention, please refer to page 20. Gas safety is integral to the design of Dorchester water heaters, and as such all burners are protected with automatic flame detection systems which will shut off the gas supply in the case of a burner flame being extinguished. Other safety systems include over-temperature protection (with lockout and manual reset) and over pressure protection on unvented systems. Frost protection is set to operate the water heater if the stored water temperature falls below 5 C is also available on all models except DR-SA/SE and DR-LP. The DR-FC Evo and DR-TC ranges have advanced electronic control and monitoring capabilities, with diagnostics for effective maintenance, as well as an alert when a service is due based on hours run. In addition to the temperature sensors and electronic controls supplied with the Dorchester DR-TC solar water heater for the safe monitoring and control of its solar circuit, there is additional solar safety equipment in the dedicated solar transfer station supplied with the water heater, including safety valves, temperature and pressure gauges and connections for a solar expansion vessel. Cover Hot water outlet Controller Pressure switch Control panel Top store temperature sensor Anode Combustion chamber Heat exchanger Mid store temperature sensor Tank Clean out door Drain valve Cold water inlet Burner assembly Air supply hose Flue gas test point Electrical connector block Plate heat exchanger supply (not used) Recirculation connection Concentric flue pipe Plate heat exchanger return (not used) Condensate trap Solar coil inlet Solar heat exchanger Solar coil temperature sensor Base Solar coil outlet Insulation layer Cutaway of a Dorchester DR-TC showing a down-firing pre-mix burner and condensing heat exchanger, with solar coil below. Dorchester Water Heaters 5

6 Dorchester DR-FC Evo Fully Automatic, Condensing Direct-Fired Water Heater The most versatile water heater from Hamworthy offering superior controls, excellent seasonal efficiencies up to 107% net and a wide range of room sealed and open flue options. 7 models Continuous outputs l/h Reduced energy costs Low noise Can be installed close W to the point of use D H Features Modulating premix burner Condensing heat exchanger Natural Gas or LPG Hamworthy flue terminals Room sealed or open flue options Flue schemes: B23, C13, C33 and C53 For open vented or unvented* water supplies Ultra-Quiet <45dBa 98% Electronic controls: ON/OFF or programmable multi-period 7 day timer with programmable extra period, hysteresis, external pump timer, anti-legionella cycle and frost protection. Remote enable. Control, limit and safety thermostats. Remote data monitor option. Corrosion protection: electrical anode Clean out door Gas Water Energy Dimensions NG LPG Specification DR-FC Evo 25 DR-FC Evo 30 Dorchester DR-FC Evo Model DR-FC Evo 45 DR-FC Evo 60 DR-FC Evo 80 DR-FC Evo 95 DR-FC Evo 120 Continuous output with 44 C T l/h Continuous output with 50 C T l/h Storage capacity l open vented water supply 8 unvented water supply 3.5 (=cold feed pressure reducing valve preset in unvented kit option) Maximum water temperature C 80 Input power, gross maximum kw Output power maximum kw Heating up time, T = 44 C min Heating up time, T = 50 C min Standby losses kw/24h Gas G20 inlet pressure nominal m 20 Gas G20 flow rate m and 15 C m 3 /h LPG G31 inlet pressure nominal m 37 LPG G31 flow rate m and 15 C kg/h Width (W) mm Depth (D) mm Height (H) mm Flue spigot diameter mm 100/ /200 Gas inlet connection type/diameter inch Rp ¾" Hot water outlet type/diameter inch R 1½" Cold water inlet type/diameter inch R 1½" Weight when empty kg Power consumption-maximum W Electrical supply V AC 230 V 1Ph 50Hz Notes: All data is based on Natural Gas G20 usage unless otherwise stated. *For unvented water supplies use optional unvented kit. For C13 and C33 flues, dedicated Dorchester flue terminals (supplied separately, and CE-approved for use with the appliance), must be used. B23 and C53 terminal and other flue components are also available. Allow clearances of 1000mm above the water heater, 1000mm around the controls and clean-out doors, and 500mm around all other sides. For full technical details, including flues, refer to the Dorchester DR-FC Evo technical brochure

7 Dorchester DR-TC Fully Automatic Solar Water Heaters with Integral Direct-Fired Condensing Gas Burner Combines the use of solar energy with a condensing gas fired water heater using an intelligent control system. 2 models 2 Transfer stations Continuous outputs l/h Saves space Prioritises solar energy over gas W D H Features Modulating premix burner Solar Transfer station with modulating solar pump Condensing heat exchanger + solar heat exchanger Solar operation with Natural Gas or LPG back-up Hamworthy flue terminals Room sealed or open flue options Flue schemes: B23, C13, C33 and C53 For open vented or unvented* water supplies Up to 30kW of solar heating 98% Electronic controls: as per DR-FC Evo, plus an integrated solar circuit control system with solar priority, and optional dummy sensor for gas-only "solar ready" operation prior to fitting any solar collectors Corrosion protection: electrical anode Clean out door Compatible with Hamworthy Trigon collectors Dorchester Water Heaters Gas Water Energy Solar Dimensions NG LPG Dorchester DR-TC Model Specification DR-TC 40 DR-TC 60 Continuous output with 44 C T l/h Continuous output with 50 C T l/h Storage capacity l 388 open vented water supply 8 unvented water supply 3.5 (=cold feed pressure reducing valve preset in unvented kit option) Maximum water temperature C 80 Input power, gross maximum kw Output power maximum kw Heating up time, T = 44 C min Heating up time, T = 50 C min Standby losses kw/24h 5.3 Gas G20 inlet pressure nominal m 20 Gas G20 flow rate m and 15 C m 3 /h LPG G31 inlet pressure nominal m 37 LPG G31 flow rate m and 15 C kg/h Maximum pressure, solar circuit kpa/() 600 (6) Transfer Station TX1 flow rate l/min 0.5 to 15 (for 2 to 15 Trigon collectors) Transfer Station TX2 flow rate l/min 4 to 22 (for 6 to 20 Trigon collectors) Width (W) mm 850 Depth (D) mm 925 Height (H) mm 2055 Flue spigot diameter mm 100/150 Gas inlet connection type/diameter inch Rp ¾" Hot/cold water connections type/diameter inch R 1½" Solar coil supply/return type/diameter inch Rp 1" Weight when empty kg 245 Power consumption-maximum W 60 + solar control (max 700) solar control (max 700) Electrical supply V AC 230 V 1Ph 50Hz Notes: All data is based on Natural Gas G20 usage, and excludes solar, unless otherwise stated. *For unvented water supplies use optional unvented kit. For C13 and C33 flues, dedicated Dorchester flue terminals (supplied separately, and CE-approved for use with the appliance), must be used. B23 and C53 terminal and other flue components are also available. Allow clearances of 1000mm above the water heater, 1000mm around the controls and clean-out doors, and 500mm around all other sides. For full technical details, including flues, refer to the Dorchester DR-TC technical brochure

8 Dorchester DR-LA/DR-LP Fully Automatic Multiple-Tube Direct-Fired Water Heaters A natural replacement for existing water heaters, the Dorchester DR-LA (or permanent pilot option DR-LP) is compatible with most existing flue designs. 13 models Continuous outputs l/h Simplifies installation in replacement projects Horizontal or vertical flue connection W D H Features Atmospheric burner Ignition: Fully automatic with flame detection(dr-la) or permanent pilot with thermocouple (DR-LP) Natural Gas or LPG Draught diverter with 45 or horizontal flue connection For B23 flue schemes or fan dilution systems* For open vented or unvented** water supplies Easy fit replacement water heater for open flued applications Exceeds Minimum Requirements Controls: ON/OFF, thermostat (control, limit and safety), power indicator, lockout and reset, volt free-contacts. Frost protection (on DR-LA only) Combustion products safety discharge device Corrosion protection: Magnesium sacrificial anode or optional electrical anode Clean out door Gas Water Energy Dimensions NG LPG Specification DR-LA/LP 30 DR-LA/LP 40 Dorchester DR-LA/LP Model DR-LA/LP 45 DR-LA/LP 60 DR-LA/LP 75 DR-LA/LP 95 DR-LA 110 Continuous output with 44 C T l/h Continuous output with 50 C T l/h Storage capacity l open vented water supply 8 unvented water supply 3.5 (=cold feed pressure reducing valve preset in unvented kit option) Maximum water temperature C 73 Input power, gross maximum kw Output power maximum kw Heating up time, T = 44 C min Heating up time, T = 50 C min Standby losses kw/24h Gas G20 inlet pressure nominal m 20 Gas G20 flow rate m and 15 C m 3 /h LPG G31 inlet pressure nominal m 37 LPG G31 flow rate m and 15 C kg/h Width (W) (with 45 draft diverter) mm Depth (D) (with 45 draft diverter) mm 800 Height (H) (with 45 draft diverter) mm Flue spigot diameter mm Gas inlet connection type/diameter inch Rp ¾" Rp 1" Hot water outlet type/diameter inch Rp 1 ½" Cold water inlet type/diameter inch R 1 ½" Weight when empty kg Power consumption W Electrical supply V AC 230 V 1Ph 50Hz Notes: All data is based on Natural Gas G20 usage, unless otherwise stated. *Flue design and terminals are not HH supply. **For unvented water supplies use optional unvented kit. Allow clearances of 1000mm above the water heater, 1000mm around the controls and clean-out doors, and 500mm around all other sides. For full technical details, refer to the Dorchester DR-LA/LP technical brochure

9 Dorchester DR-RS Room Sealed, Fully Automatic Direct-Fired Water Heaters Dedicated room sealed water heater range with multi-tube heat exchanger. 5 models Continuous outputs l/h Ideal for plant rooms with restricted ventilation or locations without a plant room D W H Features Atmospheric burner Fully automatic ignition with flame detection Natural Gas or LPG Hamworthy flue terminals For room sealed flue schemes: C13, C33 and C53* For open vented or unvented** water supplies Easy fit replacement water heater for room sealed applications Exceeds Minimum Requirements Controls: ON/OFF, thermostat (control, limit and safety), power indicator, lockout and reset, volt free-contacts Corrosion protection: Magnesium sacrificial anode or optional electrical anode Clean out door Dorchester Water Heaters Gas Water Energy Dimensions NG LPG Dorchester DR-RS Model Specification DR-RS 25 DR-RS 40 DR-RS 65 DR-RS 85 DR-RS 105 Continuous output with 44 C T l/h Continuous output with 50 C T l/h Storage capacity l open vented water supply 8 unvented water supply 3.5 (=cold feed pressure reducing valve preset in unvented kit option) Maximum water temperature C 73 Input power, gross maximum kw Output power maximum kw Heating up time, T = 44 C min Heating up time, T = 50 C min Standby losses kw/24h Gas G20 inlet pressure nominal m 20 Gas G20 flow rate m and 15 C m 3 /h LPG G31 inlet pressure nominal m 37 No LPG variant, Natural gas LPG G31 flow rate maximum m and 15 C kg/h Width (W) mm 755 Depth (D) mm 1000 Height (H) mm Flue spigot diameter mm 80/ / /200 2 x 130 (twin duct) Gas inlet connection type/diameter inch Rp ¾" Rp 1 Hot water outlet type/diameter inch Rp 1½" Cold water inlet type/diameter inch Rp 1½" Weight when empty kg Power consumption W Electrical supply V AC 230 V 1Ph 50Hz Notes: All data is based on Natural Gas G20 usage, unless otherwise stated. *Flue design and terminals are not HH supply.**for unvented water supplies use optional unvented kit. For C13 and C33 flues, dedicated Dorchester flue terminals (supplied separately, and CE-approved for use with the appliance), must be used; other flue components are also available. Allow clearances of 1000mm above the water heater, 1000mm around the controls and clean-out doors, and 500mm around all other sides. For full technical details, refer to the Dorchester DR-RS technical brochure

10 Dorchester DR-PF Power flame, Gas or Oil, Direct-Fired Fully Automatic Water Heaters Featuring a power flame burner the Dorchester DR-PF offers the highest outputs and is the only water heater that can use oil, natural gas or LPG. 6 models Continuous outputs l/h Greater flexibility with smaller flue diameter requirements Choice of fuel supply H Features Power flame Riello burner Fully automatic ignition with flame detection Natural Gas, LPG or Oil For B23 open flue schemes* For open vented or unvented** water supplies Controls: ON/OFF, thermostat (control, limit and safety), power indicator, lockout and Rapid recovery: Only 6 mins for DR-PF 145 Exceeds Minimum Requirements reset. Air and gas proving switches Combustion products safety discharge device Corrosion protection: Magnesium sacrificial anode or optional electrical anode Clean out door D W Gas and Oil 10 Water Energy Dimensions NG LPG Oil Specification Dorchester DR-PF Model DR-PF 55 DR-PF 65 DR-PF 75 DR-PF 95 DR-PF 115 DR-PF 145 Continuous output with 44 C T l/h Continuous output with 50 C T l/h Storage capacity l open vented water supply 8 unvented water supply 3.5 (=cold feed pressure reducing valve preset in unvented kit option) Maximum water temperature C 80 Input power, gross maximum kw Output power maximum kw Heating up time, T = 44 C min Heating up time, T = 50 C min Standby losses kw/24h Gas G20 inlet pressure nominal m 20 Gas G20 flow rate m and 15 C m 3 /h LPG G31 inlet pressure nominal m 37 LPG G31 flow rate m and 15 C Oil flow rate maximum, with maximum viscosity@20 C=6mm 2 /s kg/h kg/h Width (W) mm 705 Depth (D) (excluding burner) mm 725 Height (H) mm Flue spigot dia. (without adaptors) mm 150*** *** Gas inlet connection type/diameter inch Rp ¾" Hot water outlet type/diameter inch Rp 1½" Cold water inlet type/diameter inch Rp 1½" Weight when empty kg Power consumption W Electrical supply V AC 230 V 1Ph 50Hz Notes: All data is based on Natural Gas G20 usage, unless otherwise stated. *Flue design and terminals are not HH supply.**for unvented water supplies use optional unvented kit.***diameter after fitting flue reducer. Allow clearances of 1000mm above the water heater, 1000mm around the controls and clean-out doors, 600mm in front of burner and 500mm around all other sides. For full technical details, refer to the Dorchester DR-PF technical brochure

11 Dorchester DR-SA/DR-SE Fully Automatic Single-Tube Direct-Fired Water Heaters The lowest output water heaters in the Dorchester range, these are ideal for smaller applications. 4 models Continuous outputs l/h Permanent pilot option (DR-SE) Ultra quiet operation DR-SE can operate without an electrical supply D W H Features Atmospheric burner Ignition: Fully automatic with flame detection (DR- SA) or permanent pilot with thermocouple (DR-SE) Natural Gas or LPG For B23 open flue schemes or fan dilution systems* Draught diverter For open vented or unvented** water supplies DR-SE Needs no power supply Exceeds Minimum Requirements Controls: ON/OFF, thermostat (control and safety), lockout and reset. Power indicator (DR-SE only) Combustion products safety discharge device Corrosion protection: Magnesium sacrificial anode or optional electrical anode Clean out door Dorchester Water Heaters Gas Water Energy Dimensions NG LPG Dorchester DR-SA/SE Model Specification DR-SA/SE 16 DR-SA/SE 19 Continuous output with 44 C T l/h Continuous output with 50 C T l/h Storage capacity l open vented water supply 8 unvented water supply 3.5 (=cold feed pressure reducing valve preset in unvented kit option) Maximum water temperature C Input power, gross maximum kw Output power maximum kw Heating up time, T = 44 C min Heating up time, T = 50 C min Standby losses kw/24h 11.3 N/A Gas G20 inlet pressure nominal m 20 Gas G20 flow rate m and 15 C m 3 /h LPG G31 inlet pressure nominal m 37 LPG G31 flow rate m and 15 C kg/h Width (W) mm Depth (D) mm Height (H) mm Flue spigot diameter mm 130 Gas inlet connection type/diameter inch Rp ½" Hot water outlet type/diameter inch Male NPT 1" (11.5 t.p.i.) Male NPT 1 ¼" (11.5 t.p.i.) Cold water inlet type/diameter inch Male NPT 1" (11.5 t.p.i.) Male NPT 1 ¼" (11.5 t.p.i.) Weight when empty DR-SA (DR-SE) kg 117 (122) 144 (149) Power consumption DR-SA (DR-SE) W 30 (0) 30 (0) Electrical supply V AC 230 V 1Ph 50Hz 230 V 1Ph 50Hz*** Notes: All data is based on Natural Gas G20 usage, unless otherwise stated. *Flue design and terminals are not HH supply. **For unvented water supplies use optional unvented kit. *** Basic DR-SE requires no power supply 230V mains supply only required if any electrical options are to be used. Allow clearances of 1000mm above the water heater, 1000mm around the controls and clean-out doors, and 500mm around all other sides. For full technical details, refer to the Dorchester DR-SA/SE technical brochure

12 Dorchester Options *Equivalent Powerstock Options also Available Fuel Options All models can be supplied to operate with Natural Gas (G20) or LPG (G31); in addition the Dorchester DR-PF can also be supplied to operate with 35 sec oil. Changeover from one fuel type to another will require components to be changed, and any changeover must be carried out by suitably qualified and certified personnel. Unvented Supply Kit* For applications fed by unvented mains cold water supplies, Hamworthy offer an unvented supply kit which is a purpose designed and sized kit of components, supplied loose, and comprises: Strainer Pressure reducing valve 3.5 Non return valve Expansion relief valve, 6 Expansion vessel connection Expansion vessel, sized for 3.5 charge pressure Temperature and Pressure relief valve 7 at 95 C Tundish Corrosion Protection Options* All Dorchester and Powerstock models are "glass-lined". This means that a vitreous enamel coating has been applied to all internal water-side surfaces of the steel tanks, fire tubes and/or coils to ensure hygienic potable water storage and to protect from corrosion. To provide additional corrosion protection, one of two electrochemical systems are also used in all Dorchester and Powerstock models. Both systems are inherently safe and do not affect the taste of the water. These are: Electrical anode protection, or ICCP (Impressed Current Cathodic Protection) supplied as standard in DR-TC, DR-FC Evo, Magnesium sacrificial anode protection (Cathodic Protection) supplied in all other models as standard, but all models have the option to be supplied instead with an electrical anode protection system. Electrical Anode Protection* Electrical anode protection, or ICCP (Impressed Current Cathodic Protection) works by applying a 12 controlled DC protection current, via an electrical anode inserted in the tank, to maintain the tank metal within a passive electrode potential zone where corrosion is inhibited. The anode (positive) in this system is a powered titanium electrode and the tank steel is the cathode (negative). The storage water acts as an electrolyte creating an electrical circuit between anode and cathode should any tank metal come into direct contact with water. A potentiostat circuit continuously monitors the potential and automatically adjusts the anode current to maintain the tank metal at the correct potential to inhibit corrosion. For effective protection the electric anode system must always be switched on. Therefore it is essential that an uninterrupted power supply is used to ensure power is always supplied to any water heater using this system. Electrical anode protection offers excellent corrosion protection with water supplies having electrical conductivity as low as 125uS. In addition there is no sacrificial anode to replace periodically, so less maintenance is needed. Magnesium Sacrificial Anode Protection* Magnesium sacrificial anode protection, or Cathodic Protection, takes advantage of the fact that a less noble (relative position in the galvanic series) material such as magnesium will corrode in preference to a more noble material such as steel when electrically connected together and immersed in an electrolyte. In practice, the steel cylinder and internals are electrically connected to a magnesium sacrificial anode rod fitted inside the cylinder. Should for any reason damage occur to the enamelling such that the steel is allowed to come into direct contact with the stored water (the electrolyte), then an electrochemical circuit is formed, with the steel becoming the negative cathode and the magnesium rod the positive anode. The magnesium anode will then be sacrificed and corrode in preference to the steel, thus protecting the cylinder and internals from corrosion. This system has the advantage of requiring no external electrical supply, and operates with water supplies having electrical conductivity as low as 250uS. However, as part of routine maintenance, the magnesium anode will need to be checked and eventually need replacing as it will gradually dissolve over time. To assist replacement, Hamworthy can offer flexible sausage-link easy-fit replacement magnesium anodes which are particularly useful if maintenance access is restricted. Please note, electrical anode protection can, as an option, be fitted on all Dorchester water heaters that are normally fitted with magnesium sacrificial anode protection, in place of that protection. It is not possible to use both systems together in the same water heater because one system would work against the other and could potentially damage the cylinder. Also note magnesium sacrificial anodes cannot be fitted to the Dorchester DR-FC Evo or DR-TC. Top-to-Bottom Recirculation Kit* In order to prevent stratification within the heater, thus creating a zone of lower temperature water that can possibly lead to the proliferation of Legionella bacteria, an optional top to bottom re-circulation kit should be specified. By constantly returning water from the flow back into the base of the heater, a uniform temperature is maintained. The kit includes a pump, isolation valves, non-return valve and pipework for fitting on site. Typical top-to-bottom recirculation kit

13 Dorchester Options Including DR-TC Solar Options Close Temperature Control Kit (DR-LA and DR-RS only) For applications requiring above average temperature control, an optional electronic thermostat kit can be fitted. This will provide close control of the flow temperature within ±2.5 C, dependant on the operating conditions. rugged, highly efficient collectors are designed to BS EN They feature a one-piece aluminium casing and tempered glass cover housing a specially coated absorber. The Dorchester DR-TC solar system can be sized up to 40m 2 collector area using a maximum of 20 Hamworthy Trigon vertical (2.3 V) or horizontal (2.3H) flat plate collectors, in a single field of collectors (i.e. powered by a single pump transfer station), and organised in any array combination. It is recommended to use Tyfocor L as the solar fluid (40% propylene glycol) in the sealed solar circuit. This offers corrosion protection and antifreeze protection to -18 C. dedicated transfer stations for use with only the Dorchester DR-TC and not with Trigon systems. Similarly Trigon solar transfer stations cannot be used with the DR-TC control system. Dorchester Water Heaters Close temperature control kit Time Clock Control (DR-SE only) Where there is a requirement for the heater to be controlled by an external signal, such as a time clock or safety interlocks, then an optional control kit can be fitted. The kit comprises a solenoid valve that fits between the control valve and the burner. This kit will require a 230 volt, 50Hz single phase power supply. Remote Monitor/BMS Interface (DR-FC Evo/DR-TC only) A remote monitoring unit (BMS Interface) is available which acts as a bus-connection interface between the water heater controller and a Building Management System (BMS), allowing water heater data to be displayed at the BMS. Solar Options (DR-TC only) Solar Collector Field To take advantage of nominally free solar energy in place of gas heating, the Dorchester DR-TC requires a solar collector field. An appropriately sized collector field can be built quickly and easily from the Hamworthy Trigon solar products range, including vertical or horizontal collectors and associated roof or floor mounting equipment and ancillaries. Hamworthy recommend its Trigon flat-plate solar collectors for use with the Dorchester DR-TC system. These An array of two Trigon 2.3V solar collectors Dorchester Solar Transfer Stations A solar station is supplied with each Dorchester DR-TC and connects the solar collector field to the water heater solar coil. Hamworthy offer a choice of two similarly equipped solar transfer stations, TX1 and TX2. Each features a modulating pump and safety equipment such as supply and return temperature gauges, visual flowmeter, non-return valve, isolation and 6 safety pressure relief valves, and a connection for a solar expansion vessel. The TX1 is for use with systems with 0.5 to 15 l/min. solar circuit flow capacity, and for use with 4 to 30m 2 of total collector area (e.g. for 2 to 15 Trigon collectors). The TX2 is for use with systems with 4 to 22 l/min solar circuit flow capacity, and for use with 12 to 40m 2 of total collector area (e.g. for 6 to 20 Trigon collectors). Please note that TX1 and TX2 are Dorchester TX1 solar transfer station For more information on Trigon collectors and mounting equipment, transfer stations and ancillaries, please refer to the Trigon brochure Heat Meter/RHI Heat Meter Heat metering is integrated into the Dorchester DR-TC controller (requires an optional Q/T sensor). An optional Renewable Heat Incentive (RHI) compliant heat meter, with an optional RS232 Interface for this meter is also available. Remote Display A wall-mounted display unit is available which shows in real time the solar contribution of the system. Remote display Dummy Sensor A dummy sensor option allows the Dorchester DR-TC to be installed as a Solar Ready water heater, so that it can operate in a gas-burner only mode without an attached solar circuit. This is a useful option if it is intended to use the water heater ahead of completing the solar circuit. 13

14 Dorchester Water Heaters Range & Model Comparisons Key to Tables Dorchester DR-SA/SE Dorchester DR-TC Dorchester DR-PF Dorchester DR-LA/LP Dorchester DR-FC Evo Dorchester DR-RS Table 1. Dorchester Water Heaters in Order of Increasing Maximum Output Power (kw) Max. Output Power / kw Dorchester Models Table 2. Dorchester Water Heaters in Order of Increasing Maximum Continuous Outputs (Litres/Hour) Max. Continuous Output / Litre/hour Dorchester Models Table 3. Dorchester Water Heaters in Order of Increasing Recovery Time (Minutes) Max. Recovery Time / Minutes Dorchester Models Table 4. Dorchester Water Heaters in Order of Increasing Maximum Storage Volume 600 Max. Storage Volume / Litre Dorchester Models 14

15 Powerstock Calorifiers and Tanks Introduction The efficient generation of hot water for use in commercial buildings can be achieved using direct or indirect-fired heating solutions. The Hamworthy range of Powerstock calorifiers offers a flexible approach to indirect heating and storage of hot water, using a choice of energy sources. High efficiency gas fired boilers are commonly used with calorifiers as the primary energy source, but with the trend towards incorporating renewable energy into DHW systems, alternative technologies can also be used, such as solar thermal and biomass, as either the primary source, or as the primary or secondary energy source in a combined system using a twin coil calorifier. There are 7 models in the Powerstock calorifier range with continuous outputs from 569 litres/hour to 1858 litres/hour based on a temperature rise T across the calorifier of 44 C. Storage capacities are from 160 litres to 958 litres. All but the smallest models have twin coil heat exchangers which can be connected in series if using a single heat source, or connected separately when using two heat sources. Powerstock storage tanks range from 300 litres to 990 litres capacity and can be used in a variety of applications either to maximise energy efficiency or increase system security. Powerstock calorifiers and storage tanks are all approved by the Water Regulations Advisory Service (WRAS) to comply with the requirements of the UK Water Supply (Water Fittings) Regulations and Scottish Water Byelaws, when correctly installed. The Hamworthy Powerstock range of calorifiers and storage tanks provide plenty of choice in meeting hot water demands for a wide variety of commercial applications. Powerstock products are manufactured to the highest standards using the latest production technology to ensure a high quality long lasting finish in every unit. Compliance is assured with stringent controls in accordance with the European Standards for CE marking, and all models are Water Regulations Advisory Scheme (WRAS) approved. Cylinders are constructed from high grade steel with a high quality vitreous enamel lining, and the five largest units in the Powerstock calorifier range incorporate a twin coil arrangement where two separate heat sources can be used. Alternatively the coils can be linked in series to maximise the output when connecting to single heat source. Twin coil construction allows the designer to choose the configuration in which to connect the coils, to best suit the application, either in series or in parallel. This allows greater control of the heat input and gives the ability to utilise alternative energy sources such as a solar collector array. All Powerstock models are supplied as standard with a prewired control panel having a temperature control thermostat and a limit thermostat; and each model is equipped with a magnesium sacrificial anode and clean out door as standard, insulated with CFC-free PU foam for low standing losses and finished in a smart insulated PVC factory-fitted jacket. Options are available including an unvented supply kit, top-tobottom pump recirculation kit, electrical anode protection and an electric immersion heater. Powerstock Calorifiers and Tanks Seven models available in the Powerstock range of calorifiers Twin coils in Powerstock calorifiers enable two independent energy sources to be used to heat a common store. 15

16 Powerstock Calorifiers Indirect-Fired Heating and Hot Water Storage Exceeds Minimum Requirements Offering a flexible approach to indirect heating and storage, Powerstock calorifiers can be easily coupled to any heating boiler or renewable energy source to provide highly efficient hot water generation. 7 models Continuous outputs l/h Capacities l W D H Features No burner Heat exchanger coils supplied by external heat source(s) heat the stored water Twin coils for independent external heat sources For open vented or unvented* water supplies Controls: control and limit stats to control DHW flow temp via a three-port valve (not HHL supply) Corrosion protection: Magnesium sacrificial anode or optional electrical anode Clean out door Kit to connect twin coils in series Immersion heater kit options Water Energy Dimensions Specification PS160 Single coil PS200 Single coil Powerstock Calorifier PS Model PS300 Twin coil PS400 Twin coil PS500 Twin coil PS750 Twin coil PS1000 Twin coil Continuous output with 44 C T l/h Continuous output with 50 C T l/h Storage capacity l open vented water supply 10 unvented water supply 3.5 (as per preset pressure reducing valve setting in unvented kit) Maximum water temperature C 110 C (primary coil), 70 C (stored water) Input power gross-maximum** (from coil s heat source eg. boiler/solar) kw Output power maximum approx. kw min Peak Output, T = 50 C min Heating up time, T = 50 C min Standby losses kw/24h Heating up time, T = 50 C, with only optional immersion heater 9kW/(4kW) min (139) (174) (261) (348) (435) (653) (871) Width (W) mm Depth (D) mm Height (H) mm Hot water outlet type/diameter inch R ¾ R 1" R 1¼" Cold water inlet type/diameter inch R ¾ R 1" R 1¼" Coil supply/return type/diameter inch R 1" Weight empty kg Power consumption W Electrical supply V AC 230 V 1Ph 50Hz Notes: Calorifier performance is based on a DHW flow temperature of 60 C, with a cold water inlet temperature of 10 C ( T=50 C across the water heater), and a coil inlet temperature of 80 C. Input power, flow rate through coil, and coil pressure loss, are given at a coil outlet temp of 69 C (coil T =11 C). Coil data on twin coil calorifiers is for top and bottom coils together in series. *For unvented water supplies use optional unvented kit. **May need to add up to 10% on to Input Power value to account for pipework losses if heat source is non-adjacent. Allow clearances of 350mm above the water heater if unvented kit is fitted (On PS750 and PS1000 allow 1300mm for anode removal from top), 1000mm around the controls, 1000mm around the clean-out doors and in front of side-mounted anodes, and 500mm around all other sides. For full details, including top only or bottom only coil performance, refer to the Powerstock technical brochure

17 Powerstock Tanks Hot Water Storage Exceeds Minimum Requirements Powerstock tanks can be easily coupled to any indirect or directfired water heater system to augment hot water storage volumes to suit large demand applications. 4 models Capacities l Water/Energy Dimensions W D H Features For open vented or unvented* water supplies Controls: control and limit stats to control DHW loading pump (not HHL supply) Low standing losses Corrosion protection: Magnesium sacrificial anode or optional electrical anode Clean out door Fully insulated Immersion heater kit options Powerstock Tank ST Model Specification ST300 ST500 ST750 ST1000 Storage capacity l open vented water supply 10 Typically 3.5 (as per primary appliance s pressure reducing valve setting in associated unvented water supply unvented kit) Maximum water temperature C 95 C Standby losses kw/24h Width (W) mm Depth (D) mm Height (H) mm Hot water outlet (To DHW outlet) type/diameter inch R 1½" R 2 Cold water inlet type/diameter inch R 1" n/a Tank Charging Outlet (to calorifier) type/diameter inch R 1½" R 2 Tank charging inlet (from calorifier) type/diameter inch R 1½" R 2 Weight empty kg Power consumption W n/a Electrical supply V AC n/a Powerstock Calorifiers and Tanks Notes: On ST300 and ST500 tanks, allow clearance of 1300mm above the tank for anode removal/ On ST750 and ST1000 allow clearance of 1300mm in front of side-mounted anodes on ST750 an ST1000. Otherwise allow clearances of 1000mm above water heater, 1000mm around the controls and clean-out doors, and 500mm around all other sides. *For unvented water supplies use optional unvented kit. or full details, refer to the Powerstock technical brochure Powerstock Options The following options are available for Powerstock calorifiers and tanks. Immersion heaters Unvented supply kit Top-to-bottom recirculation kit Electrical anode protection With the exception of the immersion heaters, these options are similar to the equivalent options described for the Dorchesters on page 12, but will be specific to Powerstocks. Immersion Heater Option Hamworthy can supply an electrical immersion heater as an option for all Powerstock calorifiers and tanks comprising a replacement stainless steel clean out door and either a 4kW or 9kW immersion heater. As the immersion heater cannot provide the same power as a calorifier coil, heat up times will be extended when relying on the immersion heater alone (See table on page 16). Please note that with calorifier models PS160 and PS200, it is not possible to have an immersion heater at the same time as using an unvented supply kit, because the anode is relocated to the clean out door position. The immersion heater can be wired for single phase 230V or three phase 415V. 17

18 Trigon Solar and Dorchester DR-TC Solar Hot Water Solutions Trigon Solar A complete package, which delivers everything required for an integrated solar hot water solution. Vertical or horizontal collectors On-roof or A-frame installation Standard or advanced controls Integrates with Dorchester water heaters and/or Powerstock calorifiers Trigon Solar and Dorchester DR-TC Hamworthy offer two distinct solar systems, the Trigon solar system and Dorchester DR-TC solar system, and together these offer several choices to building services engineers who are integrating solar energy into commercial hot water systems. The Trigon system includes a full range of products to create and control a solar circuit. These include: Vertical and horizontal orientation high-efficiency collectors which can be connected together in arrays to quickly form a solar collector field, Modular mounting equipment and fixing kits for rapidly mounting collector arrays on different roof types or on adjustable A-frames for ground mounting, Choice of three solar transfer stations with highly efficient pumps, expansion vessels, safety equipment and ancillaries, Choice of basic or advanced electronic solar controllers, and optional monitoring and metering equipment. In addition, Hamworthy support nine pre-defined Trigon design schemes for rapid design implementation. A Trigon solar circuit is completed by connecting to a coil or coils in one or more Powerstock or equivalent calorifiers. In contrast, the Dorchester DR-TC system (see page 7 and page 13) is a solar and gas hybrid solution comprising a self-contained solar and gas powered water heater and water storage system with a dedicated solar and gas control system. A solar coil is included in each water heater, and each water heater is supplied with its own dedicated solar transfer station (choice of two) with solar pump and safety equipment. A Dorchester DR-TC system requires a solar collector field, expansion vessel and some ancillary equipment to complete its solar circuit, all of which may be selected from the Trigon range of solar products. Trigon solutions are available for single field* or dual field (e.g. an East-West roof system) collector arrangements, in any array combination up to 60m 2 area (up to 30 Trigon collectors), whereas the Dorchester DR-TC is for a single field of collectors, in any array combination up to 40m 2 (up to 20 Trigon collectors). Trigon Solar In Trigon systems solar thermal energy is commonly used via calorifiers, such as Powerstocks, with high efficiency coils to transfer the heat into stored water for distribution around a building. The solar energy can be supplemented through heat from a boiler system, or using an electric immersion heater. Alternatively, solar thermal energy may be used to pre-heat storage tanks which are used to feed the water supply to conventional direct-fired storage water heaters. This retains the seasonal efficiency benefits of separating the hot water generation from the heating system, and often enables the hot water generation to be located closer to the point of use, further reducing heat losses associated with hot water distribution systems. Trigon solar hot water systems are designed for integration with the Hamworthy Powerstock twin-coil calorifiers, to provide solar duty domestic hot water (DHW) in systems where one coil in a Powerstock calorifier is fed by the solar circuit and one is fed by hot water from a boiler. Alternatively, it can be used in two stage DHW systems where, in the first stage, the solar circuit feeds both calorifier coils (with both coils linked in series) to produce the solar pre-heated cold water feed for input to a second stage of DHW heaters. These can be either Dorchester water heaters or further Powerstock calorifiers which subsequently generate the duty DHW output. Trigon solar systems are an attractive proposition as they profit from free solar energy whenever feasible. The more the calorifier is heated by solar energy, the less energy from other means is required to satisfy the heat demand at the DHW output, and so the greater the saving in fossil fuel, and the greater the carbon reduction. Trigon systems become even more attractive when combined with Hamworthy high efficiency gas, oil or biomass boilers for top-up, night time and anti-legionella purge cycle heating; creating highly cost effective, energy efficient, low carbon emission systems. Dorchester DR-TC Solar System Solar thermal energy can also be deployed using the Hamworthy Dorchester DR-TC system which is a hybrid system combining solar heating and condensing direct gas fired heating within a single storage water heater. The Dorchester DR-TC offers a compact, close to point-of-use solution as an alternative to a full Trigon system. Its built-in solar coil, solar transfer station and integrated solar controls work together with a Trigon, or equivalent, field of collectors, to provide solar heating whenever the collector temperature rises to a few degrees above the temperature of the stored water. With solar heating prioritised whenever feasible, gas consumption is minimised and carbon emissions are reduced, making a highly efficient hot water solution. For more detailed information on the Dorchester DR-TC refer to the Hamworthy Dorchester DR-TC brochure: For more detailed information on the Trigon system refer to the Hamworthy Trigon brochure: A block diagram comparing the two systems key components is shown on the next page. Note *A solar field is defined here as an arrangement of one or more collectors, grouped in single or multiple arrays that belong to the same closed solar circuit, and with solar fluid flowing through it controlled by a single pump. 18