RENEW 2104 EFFICIENT HOT WATER BUYERS GUIDE

Transcription

1 Table 1. Solar hot water systems Apricus Australia ph: Chromagen Pty Ltd ph: ECOSOLAR ph: 0800 ECOSOLAR (NZ) or info@ecosolar.co.nz Type ( Tank 1 ReNew Issue 129 renew.org.au Collector Glass type Boosting RRP AE-250-TS-MID Evacuated Stainess steel Polyurethane tubes Copper header on a steel Borosilcate $ years on manifold tubes, tube system foam backing glass (twin heat pipes and frame, 10 AE-315-TS-MID $5185 glass) years on tank, 1 year on AE POA pump and controller AE-315-GL-BOT Vitreous enamel 4.35 $ years on manifold tubes, heat pipes and frame, 5 AE-315-GL-MID $4485 years on tank, 1 year on AE-250-GL-BOT tubes $3905 pump and controller AE-250-GL-MID tubes $3905 AE-400-GL-MID $4825 AE-400-GL-BOT tubes $5575 AE-400-GL-MID tubes $5575 AC-315-TS-26N Stainless steel 4.35 Gas $ years on manifold tubes, heat pipes and frame, 10 years on tank, 1 year on pump and controller AC-315-GL-26N Vitreous enamel 4.35 $ years on manifold tubes, AC-400-GL-26N heat pipes and frame, tubes $5660 years on tank, 1 year on pump and controller Chromagen SmartLine 200 Integrated Gas Open Loop Chromagen SplitLine 200 Open Loop Chromagen SplitLine 200 Closed Loop Chromagen SplitLine 300 Open Loop Chromagen SplitLine 300 Closed Loop Chromagen SplitLine 400 Open Loop Chromagen Roofline 200 Open Loop Chromagen Roofline 300 Open Loop Chromagen Roofline 300 Closed Loop 200 Split system with integrated Split system Vitreous enamel Polyurethane foam 2.6 to to Ultra-selective blue sputtered coating or selective black paint. Dependent on individual application. Low-iron, tempered glass 200 Close-coupled Gas Gas / electric EC180DB 2.8ST 180 Closed loop drainback, Duplex grade Glasswool Copper plate, copper split system, flat-plate stainless steel pipes EC330DB 4.6ST EC330DB 5.6ST EC425DB 6.9ST EC180OL 2.8ST 180 Open loop, split system, EC330OL 4.6ST 330 flat-plate EC330OL 5.6ST EC425OL 6.9ST Commercial DB As per design Closed loop drainback, split system, flat-plate 4.3 As per design As per design Prismatic low-iron safety glass Gas Gas / electric POA Both flate plate and evacuated tube available. Collector type is determined by roof orientation and/or climate. Visit chromagen.com.au for a solar hot water guide including more detail and other system options. 5 years tank cylinder and with 3 years labour. All other, 1 year parts and labour POA - 5 years on and tank and 1 year on pump Commercial systems designed to suit application

2 Edson Pty Ltd ph: Endless Solar ph: Genersys Solar Australia Pty Ltd, distributed By SolarArk ph: ph: Type ( Tank ES Evacuated tube system Stainless steel Polyurethane tubes Copper header on an ES foam 4.63 anodised aluminium backing ES tubes ES ES tubes ES ES tubes Collector Glass type Boosting RRP Borosilcate glass (twin glass) ES LP tubes LPG ES LP tubes ES LP ES LP ES LP tubes ES LP tubes ES LP ES LP ES LP tubes ES LP ES LP tubes ES NG tubes Natural ES NG tubes ES NG ES NG ES NG tubes ES NG tubes ES NG ES NG ES NG tubes ES NG ES NG tubes ES-E Modular split system. Australian-made Polyurethane tubes Anodised aluminium High ES-E High efficiency marine-grade tubes manifold with copper impactresistance 3.6 kw). Mid (bottom evacuated tube stainless steel. heat exchanger, ES-E Naturally No sacrificial 4.6 evacuated tubes with borosilicate element also ES-E frost tolerant (no anode required tubes centralised copper heat glass tubes. available ES-G N glycol required). Mains Highly insulated tubes pipes, and stainless steel Complies Natural or pressure mounting frame with ES-G N LPG Australian ES-G N-40 Commercial models 315 As tubes Standard 2712:2007 required Industrial models 1450 Vacuum Flat Plate 200 upwards Mains pressure, closed circuit heat exchanger, flat-plate Stainless steel Glasswool/ polyurethane POA Includes all valves and fittings POA Australian designed and proven in the Australian climate for over 10 years. Frost tolerant to -15 C (does not require glycol). Very effective in winter and colder climates. Australian Standards approved and Watermarked. As required As required As required Custom designed and computer modelled to suit application (actual collecting surface area) (actual collecting surface area) - Vacuum design, aluminium (AlMg) one-piece construction, aluminium oxide highly selective surface Aluminium (AlMg) one-piece construction, aluminium oxide highly selective surface Safety solar ESG white glass 4mm Gas, condensing heat pump, biomass POA High-end domestic, commercial, industrial and swimming pool use. 10 panels connected in series. Available as horizontal mounted panel, model H. High-end domestic & commercial use. 10 panels in series 15 years on manifold tubes, heat pipes and frame, 20 years on tank, 1 year on pump and controller, 5 years on valves 15 years on major components 5 years on major components 15 years on, 15 years on stainless tank 2 ReNew Issue 129 renew.org.au

3 Rheem Australia Pty Ltd ph: Type ( Tank Collector Glass type Boosting RRP 52H180K/1S-G 180 Premier Hiline roof Stainless steel Polyurethane 2 1 Mild steel Low-iron Gas POA Space-saving design. 52H300K/2S-G 300 mounted, close-coupled. tempered Low-maintenance, no Suitable for frost-prone pump required 52H180/1S 52H300K/2S areas & areas with poorer water quality C180/1NPT-G 180 Premier Hiline roof Vitreous enamel 2 1 Aluminium Gas Space-saving design. Lowmaintenance, 52C300/2NPT-G 300 no pump mounted, close-coupled. Suitable for frost-prone required. 52C180/1NPT 52C300/2NPT areas & areas with poorer water quality S160/1NPT-G 160 Hiline roof mounted Vitreous enamel 2 1 Aluminium Gas Space-saving design. 52S300/2NPT-G S160/1NPT S300/2NPT 300 Low-maintenance, no pump required. Suitable for warmer climates 596/2S Premier Loline split Vitreous enamel Mild steel Gas Split design reduces the 596/3S system. Suitable for structural load on the roof 6 3 frost-prone areas and 590/2S-G areas with poorer water 590/3S-G quality /2S 591/3S /1TBT26-G 160 Loline split system Vitreous enamel Copper Gas Suitable for cooler climates /2NPT-G Aluminium Split design reduces the /2NPT-G 325 structural load on the roof. Suitable for warmer /3NPT-G climates /2NPT /2NPT /3NPT L Mains pressure closecoupled. Stainless steel Polyurethane 2 1 Copper/aluminium Low-iron L Suitable for (Australis, Australis 10 tempered non-frost areas ) or titanium L11 GS L32 GS coated copper absorber (Titan ) Gas POA Australis : aluminium with copper tubing. Titan : titanium coated copper with copper tubing LX Mains pressure closecoupled. 2 1 *Australis - LX Heat-exchange aluminium with copper frost protection tubing. *Titan LX11 GS LX32 GS Gas - Titanium coated copper with copper tubing. 7 years cylinder, 5 year solar, 1 year labour on cylinder, 1 year parts inc labour. Applies to domestic installations only. 5 years cylinder, heat exchanger and solar, 3 year labour on cylinder and heat exchanger, 1 year parts inc labour. Applies to domestic installations only. 7 or 10 years on cylinder depending on system 7 or 10 years on cylinder depending on system 3 ReNew Issue 129 renew.org.au

4 Rinnai Solar ph: Type ( Tank SS180H1EXT 180 Close-coupled Stainless Glass wool/ 2 1 Aluminium / copper SS330H2EXT 330 steel Polyurethane TiNOX absorber CCSE2001A 200 Vitreous enamel 2 1 Aluminium / copper CCSE3302A 330 SS180H1EXTRG 180 Stainless 2 1 Aluminium / copper SS330H2EXTRG 330 steel TiNOX absorber CCSG2001A 200 Vitreous enamel 2 1 Aluminium / copper CCSG3302A 330 MSS250H2EXT 250 Split system Stainless Aluminium / copper MSS315H2EXT 315 steel TiNOX absorber SM250SL2A 250 Vitreous enamel Aluminium / copper SM315SL2A 315 SS2502EXTRG 250 Stainless Aluminium / Copper SS3152EXTRG 315 steel TiNOX absorber SG1751A 175 Vitreous enamel 2 1 Aluminium / copper SG1751L SG2152A 215 SGSL2A MSS250HEVT25A 250 Stainless tubes Aluminium header and MSS315HEVT30A 315 steel frame assembly with 4.9 copper heat pipes SM250SLEVT25A 250 Vitreous enamel tubes SM315SLEVT30A Collector Glass type Boosting RRP Low-iron tempered Borosilicate glass 2.4 kw or 3.6 kw S20 or S26 Rinnai continuous flow 2.4 kw or 3.6 kw S20 or S26 Rinnai continuous flow 2.4 kw or 3.6 kw SS250EVT25ARG 250 Vitreous enamel tubes S20 or S26 Rinnai SS315EVT30ARG continuous SG175EVT20A tubes flow SG175EVT25A tubes SG215EVT25A tubes SGSLEVT30A 4.9 Commercial systems Varies Stainless steel and vitreous enamel lined mild steel POA Australian-made using high-performance selective surface. Australian-made stainless steel tanks. Frost-tolerant available for temperatures as low as -6 C. Dedicated continuous flow booster, same technology as the Rinnai Infinity. High STCs awarded due to high performance of the system Australian-made stainless steel tanks. Frost protection for temperatures as low as -12 C. Dedicated continuous flow booster, same technology as the Rinnai Infinity. High STCs awarded due to high performance of the system Varies Varies Varies Varies Heavy duty Contact Rinnai with your project and a system can be tailor-made to maximise your return on investment 5 years on vitreous enamel lined tanks, 10 years on stainless steel tanks 7 years on flat-plate, 15 years on evacuated tube 12 years on booster heat exchanger 5 years on stainless steel tanks, 5 years on heavy duty continuous flow heat exchanger 4 ReNew Issue 129 renew.org.au

5 Run On Sun Australia Pty Ltd ph: (02) Type ( Tank Collector Glass type Boosting RRP ROSAHP150EL 160 Close-coupled 316 L marine Polyurethane tubes Selective surface, Borosilcate 2-Kw $3160 Includes all valves required, ROSAHP200EL 220 evacuated tubes with grade stainless foam Sydney tubes with 2 mm glass (twin pipe insulation, spare tubes 2-Kw $3830 copper heat pipes steel thick glass plus copper glass) 2 mm tubes, 2 mm stainless steel ROSAHP250EL ROSAHP150G tubes heat pipes thick 2-Kw Gas Bosch 21e $4265 $4132 frame, cyclone mount kit and free freight ROSAHP200G tubes Gas Bosch 21e $4800 ROSAHP250G 4.8 Gas Bosch 21e $5265 SPLIT250-24EL Split system with Vitreous enamel Polyurethane tubes AIN/AIN-SS/CU surface, Borosilcate mid $3390 Includes Grundfos pump evacuated tube foam Sydney tubes with 2 mm glass (twin station that can attach to SPLIT315-30EL mid $3690 thick glass plus copper glass) 2 mm the tank. -boosted SPLIT400-48EL tubes heat pipes. Stainless thick mid $4490 models with mid-element steel manifold housing boost. Optional cost-price SPLIT250-24G tubes Gas Rinnai S21 $4090 valve kit and brassware SPLIT315-30G Gas Rinnai S21 $4350 with insulation gloves SPLIT400-48G tubes Gas Rinnai S21 $5090 SPLIT315-30G Gas Rinnai S26 $4550 SPLIT400-48G tubes $5290 Retrofit evacuated tube NA Evacuated tube NA Rockwool tubes 18 tubes AIN/AIN-SS/CU surface, Sydney tubes with 2 mm Borosilcate glass (twin Existing tank $720 $1010 Includes evacuated tube with a 2 mm tubes thick glass plus copper glass) 2 mm $1340 thick stainless steel frame. heat pipes. Stainless thick Optional pump, controller, 4.8 steel manifold housing $1550 air/steam eliminator and a one-way valve $350. AC or DC pump available 7 years on the tank 14 years on the evacuated tubes 14 years on the frame and mounting kit. 10 years on the tank 14 years on the evacuated tubes 14 years on the frame and mounting kit 5 years on the pump and controller 14 years on the evacuated tubes 14 years on the frame 5 years on the pump and controller Solahart ph: (02) Jg or KFg 180 Mains pressure closecoupled. Closed circuit J = non-selective surface Vitreous enamel Polyurethane 2 1 Mild steel 222Jg or KFg 220 heat exchanger. Suitable KF = selective surface 302Jg or KFg 300 for frost and/or poor chrome black 443Jg or KFg 440 water areas J or KF J or KF J or KF J or KF Lg 180 Mains pressure 2 1 Aluminium 222Lg 220 close-coupled system. L = non-selective surface Suitable for non-frost LCS = selective surface 302Lg or LCSDg 300 and good water areas. 443Lg Low iron Gas Ask your local dealer for a free 181Lg Lg L or LSCD Lg MLVg Mains pressure split Aluminium Gas 322MLVg 320 system. Suitable for L = non-selective surface non-frost and good 412MLVg 410 water areas. Limited 413MLVg 410 frost protection MLV 322MLV MLV MLV Gas onsite quote 300 litre range also available in a Free Heat version with an extended warranty 300 litre range also available in a Free Heat version with an extended warranty Models with a selective surface are available for southern areas For single family domestic dwellings, standard thermosiphon series is 5/5/5: 5 years supply tank and, 5 years labour tank and, 5 years components supply and labour, Free Heat series is 10/5/5: 10 years supply tank and, 5 years labour tank and, 5 years components supply and labour For single family domestic dwellings, split series is 5/3/2: 5 years supply tank and, 3 years labour tank and, 2 years components supply and labour 5 ReNew Issue 129 renew.org.au

6 SolarArk Pty Ltd ph: Type ( Tank 6 ReNew Issue 129 renew.org.au SA-M-20-VE250 SA-M-30-VE250 SA-M-20-VE315 SA-M-30-VE315 SA-M-40-VE315 SA-M-30-VE400 SA-M-40-VE Split system Vitreous enamel Polyurethane tubes 20 tubes 40 tubes 40 tubes Aluminium manifold with SolarArk copper heat exchanger, Tri Target evacuated tube with copper heat pipe, and stainless steel mounting frame SA-M-30-VE SA-M-30-VE SA-M-40-VE tubes SA-M-60-VE tubes SAC-M-60-VE tubes SA-M-20-SS Stainless steel tubes SA-M-30-SS SA-M-20-SS tubes SA-M-30-SS SA-M-40-SS tubes SA-M-30-SS SA-M-40-SS tubes SA-M-30-SS SA-M-40-SS tubes SA-M-60-SS tubes SAC-M-60-SS tubes SAC-M-90-SS tubes SA-R-20-VE-G250-20N/LPG 250 Vitreous enamel SA-R-20-VE-G250-26N/LPG tubes SA-R-20-VE-G315-20N/LPG tubes SA-R-20-VE-G315-26N/LPG tubes SA-R-30-VE-G315-20N/LPG SA-R-30-VE-G315-26N/LPG SA-R-40-VE-G315-26N/LPG tubes SA-R-40-VE-G315-32N/LPG tubes SA-R-30-VE-G400-26N/LPG SA-R-40-VE-G400-26N/LPG tubes SA-R-40-VE-G400-32N/LPG tubes SAC-G-60-VE-G945-32N tubes SAC-G-90-VE-G945-32N tubes SA-G-20-SS250-G-20N/LPG 250 Stainless steel tubes SA-G-20-SS250-G-26N/LPG tubes SA-G-30-SS250-G-20N/LPG SA-G-30-SS250-G-26N/LPG SA-G-20-SS315-G-20N/LPG tubes SA-G-20-SS315-G-26N/LPG tubes SA-G-30-SS315-G-20N/LPG SA-G-30-SS315-G-26N/LPG SA-G-30-SS315-G-32N/LPG SA-G-40-SS315-G-26N/LPG tubes SA-G-40-SS315-G-32N/LPG SA-G-30-SS400-G-20N/LPG SA-G-30-SS400-G-26N/LPG SA-G-40-SS400-G-26N/LPG tubes SA-G-40-SS400-G-32N/LPG tubes SA-G-40-SS500-G-26N/LPG tubes SA-G-40-SS500-G-32N/LPG tubes SA-G-40-SS630-G-26N/LPG tubes SA-G-40-SS630-G-32N/LPG tubes SAC-G-60-SS945-32N tubes Collector Glass type Boosting RRP 2 mm thick borosilicate glass tubes Rinnai Solar instantaneous POA Australian designed and owned. Meets all Australian standards including Watermark 15 years on major components

7 Solar Lord ph: Type ( Tank 7 ReNew Issue 129 renew.org.au EU15-O E340U15-O 340 Mains pressure, split system, open circuit, Vitreous enamel Polyurethane 1 (15 x 2100mm long U-tubes) E450U30-O 450 suitable for good quality 2 (30 x water, antifreeze level 2 E450U45-O (45 x GU15-O 1 (15 x 2100mm G340U15-O 340 long U-tubes) G450U30-O (30 x G450U45-O (45 x E180H16-O 180 Mains pressure, split system, open circuit, suitable for hard to poor quality water, antifreeze 1 (16 x 1800mm EH24-O 1 (24 x 1800mm E340H32-O 340 level 2 2 (32 x E450H40-O (40 x E450H48-O (48 x G180H16-O (16 x 1800mm GH24-O 1 (24 x 1800mm G340H32-O (32 x G450H40-O (40 x G450H48-O (48 x E450U45-OH E450H48-OH G450U45-OH Mains pressure, split system, open circuit, suitable for hard to poor quality water, antifreeze level 2 Vitreous enamel with copper coil for hydronic heating 3 (45 x 3 (48 x 2 (45 x G450H48-OH (48 x E250U15-O 250 Mains pressure, split E315U15-O 315 system, open circuit, antifreeze level 2 Stainless steel 1 (45 x 2100mm long U-tubes) Collector Glass type Boosting RRP AIN/AIN-SS/CU surface, novel sputtering treatment, U copper tubes AIN/AIN-SS/CU surface, novel sputtering treatment, heat pipe U copper tube Heat pipe AIN/AIN-SS/CU surface, novel sputtering treatment, U copper tubes Evacuated borosilicate glass tube Continuous/ off-peak electric Instantaneous Continuous/ off-peak electric Instantaneous Continuous/ off-peak electric Instantaneous Continuous/ off-peak electric G250U15-O 250 Instantaneous G315U15-O 315 E250H24-O (24 x 1800mm E315H32-O (32 x G250H24-O (24 x 1800mm G315H32-O (32 x AIN/AIN-SS/CU surface, novel sputtering treatment, heat pipe Continuous/ off-peak electric Instantaneous POA Winner of HIA GreenSmart Award Product of the Year Easy and cost-saving installation, good performance in winter and on overcast and rainy days. Winner of HIA GreenSmart Award Product of the Year Good performance in winter and on overcast and rainy days. Good performance in winter and on overcast and rainy days. Easy and cost saving installation, good performance in winter and on overcast and rainy days. 10 years on instantaneous booster 10 years on construction 7 years on tank 2 years on parts 10 years on instantaneous booster 10 years on construction 10 years on tank 2 years on parts

8 SolarOz ph: Vulcan ph: Type ( Tank SPZ58/ Close-coupled Stainless steel PU foam 0.96 SPZ58/ SPZ58/ SSHE58/ SSHE58/ SSHE58/ SPHE58/ SS300E30T 300 Split system 2.4 SS400E40T SS500E60T Collector Glass type Boosting RRP 12 tubes 58 mm x 1800 mm x 24 tubes 2 mm thick evacuated tube with three layer coating 12 tubes Wood fire, electric, 24 tubes Aluminium/copper, 40 tubes 60 tubes /2HBT-G 160 Spilt system. Suitable for Vitreous enamel Polyurethane Copper Low-iron frost-prone areas. tempered /2HBT /2NPT-G Aluminium /2NPT, POA - 10 years on tubes and frame, 5 years on tank, 1 year on electrical Gas POA Split design reduces the structural load on the roof 5 years cylinder, and electronic instantaneous heat exchanger, 3 years labour on cylinder and electronic instantaneous heat exchanger, 1 year parts including labour. Applies to domestic installations only. 8 ReNew Issue 129 renew.org.au

9 Table 2. Heat pump hot water systems Chromagen Pty Ltd ph: Quantum Energy Technologies ph: Type Tank Midea HP Heat pump Vitreous enamel Midea HP Refrigerant type Boosting (if used) Coefficient of performance Min rated ambient temp Noise level (db) RRP (pre R134a 48 POA 5 years tank cylinder, 3 years compressor and electronics, 3 years labour on tank cylinder, all other 1 year parts and labour ACW ACW AC AS AC AS Compact heat pump Compact heat pump Compact heat pump Split system Compact heat pump Split system Vitreous enamel Polyester (no ozone depletion) R134 or R134a depending on model. Not required 3.67 (@20 C) 3.67 (@20 C) 3.88 (@20 C) 3.88 (@20 C) 3.88 (@20 C) 3.88 (@20 C) -10 C POA No booster element required operates in temperatures of -10 C to +40 C. Regulates the refrigerant temperatures to prevent freezing and overheating. Built in timer (AC4 models) to maximise efficiency. Excellent for use in poor water conditions the water does not make contact with any operational components, only ACW Compact heat pump 3.74 (@20 C) 58 the inner lining of the tank. Low noise rating (AC4 models) at ASW Split system 3.74 (@20 C) db. Tank-wrap design. 5 years on cylinder, 2 years on refrigeration and electrical components; extended warranty available through product registration with Quantum Rheem Australia Pty Ltd ph: Sanden ph: (02) sales@sanden.com.au Siddons Solarstream 1300 SID SOL ph: (03) contact@siddonssolarstream. com Stiebel Eltron ph: info@stiebel.com.au HDi-310 integrated heat pump Vitreous enamel MPi-325 integrated heat pump MPi-410 integrated heat pump MPi-325 integrated heat pump Rheem Plus GAUS - 160EQTA 160 Split system Marine-grade GAUS - 250EQTA 250 stainless steel GAUS - 250EQTB 250 GAUS - 315EQTD 315 GAUS - 315EQTE 315 GAUS - 315EQTF 315 GAUS - 315EQTG 315 MAHRW010ZB-315VEO 315 Split system heat Vitreous enamel pump water heater, suitable for mineralised water Polyurethane R134a POA Back-up element fitted in every model Polyurethane R744 (CO2) None POA Save up to 78% of your hot water energy costs. Perfect for use with off-peak electricity tariffs for even more savings. Polyurethane R134a None 2.5 to C 48 POA Split system, Australian-made, vitreous enamel lined steel storage tank with anode MAHRW010ZB-315VED POA MAHRW010ZB-250SS 250 Split system and Stainless steel 48 $3390 Split system, Australian-made, all-in-one heat pump stainless steel (316) storage tank MAHRW010ZB-315SS $3690 water heater MAHRW010ZAB- MAHRW010ZAB- (01) MAHRW010ZAB $3390 POA $3690 All-in-one, integrated stainless steel (316) storage tank and heat pump MAHRW010ZAB-340(01) POA MAHRW010ZB-P N/A BOLT-ON heat pump to add to existing tank WWK300 A 303 Compact heat pump Vitreous enamel WWK300 AH N/A 48 $1890 Suitable for vitreous enamel and stainless steel storage tanks Polyurethane R134a None $3575 inc GST Smart $3850 element inc GST 1.7 kw Active defrost, external or internal installtion 5 years cylinder warranty, 3 years labour on cylinder, 2 years on sealed system including labour. 1 year on all parts and labour. Applies to domestic installations only. 15 years on tanks and 3 years on heat pump unit 5 years storage tank, 3 years heat pump, 1 year labour 10 years storage tank, 3 years heat pump, 1 year labour 10 years storage tank, 3 years heat pump, 1 year labour 3 years heat pump, 1 year labour 5 years on tank, 2 years on compressor and refrigerant circuit and 1 year on electrical components 9 ReNew Issue 129 renew.org.au

10 Table terms explained 'Sydney tubes': another term for the most common type of evacuated tubes. Named after the Solar Energy Research Group at the University of Sydney as they developed an all-glass evacuated tube for solar which has become the industry standard design. Closed loop: Also called a closed circuit or indirect system, closed loop systems use a heat exchanger in the tank which is coupled to the. Heat transfer fluid circulates between the solar and the heat exchanger, transferring the heat to the potable water in the tank. The heat transfer fluid and the water are never in contact. Closed loop systems may use water in the closed loop, but normally use low freezing point liquids such as propylene glycol, especially if installed in frost-prone areas. Closed loops may be used in both close-coupled and split systems. Open loop: Also called direct systems, open loop systems have the directly coupled to the tank. The potable water in the tank flows between the tank and the and is itself the heat transfer fluid. Direct systems are not usually used in frost-prone areas due to the risk of water freezing in the. Drainback system: A system using an unpressurised closed loop where there is an air space in the loop and a small reservoir for the heat transfer fluid. Heat transfer fluid (usually pure water) is pumped to the where it is heated and drains back under gravity. Drainback systems have some advantages over other closed loop systems they can prevent system overheating simply by turning off the circulating pump. The same applies for freeze protection. Their main disadvantage is that the pump will use more energy compared to a regular closed loop system as it has to overcome gravity to push water up to the. Some drainback systems may even have two pumps, the second circulates potable water from the main tank to the HTF tank's heat exchange coil for heating. Selective surface: a surface coating that increases solar absorption while decreasing heat emission. Used to make solar more efficient. References for table data Grades of stainless steel: wiki/sae_steel_grades#stainless_steel List of refrigerants: List_of_refrigerants 10 ReNew Issue 129 renew.org.au