Staying liquid, even at sub-zero temperatures

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Solar thermal Market Overview heat Transfer Fluids Staying liquid, even at sub-zero temperatures A good heat transfer medium should not only protect against frost, it should also prevent corrosion

The S&WE market overview provides information on tried-and-tested products as well as market innovations for solar energy systems and heat pump circuits.

1 Solar thermal Market Overview heat Transfer Fluids Staying liquid, even at sub-zero temperatures A good heat transfer medium should not only protect against frost, it should also prevent corrosion and require minimal energy to pump, even in the winter. The S&WE market overview provides information on tried-and-tested products as well as market innovations for solar energy systems and heat pump circuits. Most heat transfer fluids are based on glycols. However, depending on the application and manufacturer, they can differ significantly. Photo: Tyforop Antifreeze fluids for solar thermal systems and heat pumps are not spectacular. Nevertheless, selecting the wrong product can cause a lot of trouble. Incompatible materials can cause corrosion, and in the worst case scenario, the piping will even need to be replaced. Using a heat pump fluid with a high viscosity can increase power consumption during the winter, and this can undermine energy efficiency. The S&WE market overview provides a quick summary of the main characteristics of the fluids: Antifreeze fluids for solar thermal systems are usually based on monopropylene glycol (MPG), which is also simply called propylene glycol. Glycols with higher boiling points are less commonly used (see Table 1). Under no circumstances should antifreeze fluids based on different materials be mixed together. Mixing is not even recommended if the base materials are identical because the additives may be incompatible with each other. Fluids designed for use in vacuum tube collectors need to be able to withstand higher temperatures. If the absorber is made completely of aluminium, then special corrosion protection is important. In addition, aluminium is not only sensitive to ph values that are too low, it can also be damaged by ph values that are too high (starting at approximately 9). Table 1 provides an overview of different collector types and materials, and which fluids are suitable in each case. Other characteristics such as thermal conductivity are important, but they only differ slightly from product to product. All of the fluids are water hazard class 1. For this reason, this information is not given in Tables 1 and 2. Some manufacturers do not provide information on the water hazard class. The tables also provide information on the density of the fluid, allowing volumes and masses to be easily factored in for price comparisons. The prices themselves are not listed because sales channels and quantities may differ, and these will affect the prices Thermochema provides the ideal antifreeze for any application! Rusted up? Prevent it! WITH ANTIFROGEN HEAT TRANSFER FLUIDS. 6 Antifreeze for solar plants, heating systems and heat pumps 6 Biodegradable 6 Suitable for use in food businesses 6 Including special high quality inhibitors for corrosion protection on organic basis 6 10 years anti-corrosion guarantee 32 Sun & Wind Energy 4/2016

Climalife Groupe Dehon Advertorial What is in your pipes? When you think about solar thermal systems, you think about harnessing the energy from the sun and not using petroleum-based energy resources.

2 Climalife Groupe Dehon Advertorial What is in your pipes? When you think about solar thermal systems, you think about harnessing the energy from the sun and not using petroleum-based energy resources. However, in order to make solar thermal systems effective, they need a fluid to transport the sun s energy from the roof top collectors to the heat exchangers where the thermal heat is needed. These fluids may need to stand up to temperatures exceeding 150 C without phase changes for optimal performance so glycol-based heat transfer fluids are commonly used. The problem with most of these glycol fluids is that they are based on petroleum chemistry, which means your environmentally friendly solar thermal system is not as green as you might have hoped. Climalife has recently introduced an improved heat transfer fluid. Greenway Neo Solar heat transfer fluid provides excellent performance under high temperature conditions and avoids using fossilderived, petroleum-based resources. Its unique composition is based on a high performing glycol, Susterra 1.3 propanediol by DuPont Tate & Lyle Bio Products Company, and a new generation of organic inhibitive products to deliver a stable, 100 % biobased and Borax-free fluid. Greenway Neo Solar fluid testing indicates that under solar stagnation conditions and high pressures it does not decompose as rapidly as other fluids. In fact, it has the potential to increase the lifetime of the installation as it maintains its efficiency. With less decomposition and sludge formation it significantly reduces the need for maintenance and therefore may generate operating savings while preventing corrosion in the system. This heat transfer fluid is approved by ANSES (French Agency for Food, Environmental and Occupational Health & Safety), and Belgaqua (the Belgian federation of the water sector). It is approved by ISO standard on its ability to prevent bacte rial growth in a circuit. It also meets the OECD standard 302 B intrinsic primary biodegradability of 90 % to 100 % in 28 days. dehon service SA Climalife 26, Avenue du Petit Parc Vincennes Cedex Paris, France Phone : +33 / contact@climalife.dehon.com Website: Dynamic viscosity is an important characteristic of antifreeze fluids for heat pump systems. The lower the dynamic viscosity, the less energy is required for pumping. Values are often specified for 20 C, but values at lower temperatures are more meaningful. For Table 2, we asked manufacturers to provide data for 0 C and to indicate differing values. Price tensions are relaxing In view of the current slump on the solar thermal market, it is difficult to talk about trends for solar fluids. Even though manufacturers offer a wide range of products, including fluids for aluminium collectors, for high temperatures and antifreeze fluids made from renewable raw materials, they are not reporting anything that might be a new trend. On the bright side, the competition to print higher and higher temperatures on the data sheet that are measured under unspecified conditions or under conditions that are not comparable to anything seems to be over. We are not seeing an increased interest in solar fluids with higher temperature resistances. In fact, the latest innovations from some system vendors aim to reduce or even completely prevent overheating of solar energy systems, said Frank Hillerns of Tyforop from. Price tensions are beginning to relax. The price of oil is low, and price spikes due to events such as cold snaps that cause the price of glycol to shoot up have not occurred recently. The oil price is only one of several factors that affect glycol prices. There are constant fluctuations in prices of glycols. Depending on our agreement with the customer, we either adjust our prices to the current market or we agree to a fixed annual price, said Sascha von Jeinsen at Staub & Co. Silbermann from. The innovations at a glance GHC Gerling, Holz & Co. Handels GmbH is a new addition to our overview. It has been on the market with a solar thermal product and a product for heat pump systems for approximately one year now. The company has been in business with various chemical gases, containers and related products for a long time, and it has also been selling the Antifrogen antifreeze fluid from Clariant for an equally long time. The manufacturer GHC is now in the S&WE overview for the first time with inexpensive proprietary products. Staub & Co. Silbermann introduced two new products for brine-water heat pumps in March: the cooling brine concentrate N-Geo, which is based on ethylene glycol, and the cooling brine concentrate Spezial-Geo, based on propylene glycol. The inhibitors in both products have been adjusted to the higher proportion of plastics in the piping of geothermal systems. Compared to other antifreeze fluids, they are also slightly less expensive. According to the manufacturer, the temperature stability of the solar fluids has been improved. For the heating and cooling fluids, this mainly equates to more storage capacity for raw materials and products. This enables us to survive shortages and temporary price increases for materials such as glycols. For our customers, this Solar Edition 33

3 Solar thermal Market Overview heat Transfer Fluids Heat transfer fluids for solar thermal systems Manufacturer Product Antifreeze Delivery form 2 types Suitable collector Suitable materials Minimum temperature [ C] Density [g/cm 3 ] 1 Aqua-Concept, Coracon Sol 5 HF dipropylene glycol ready FPC, ETC, (HP, DF) Al/Cu/VA Coracon Sol EKO MPG (RRM) conc FPC, ETC, (HP, DF) Al/Cu/VA n/a Coracon Sol EKO F MPG (RRM) ready FPC, ETC, (HP, DF) Al/Cu/VA Clariant, Switzerland Antifrogen Sol HT high boiling glycols ready FPC, ETC, (HP, DF) Al/Cu/VA -23 approx Antifrogen Sol HT Conc. high boiling glycols ready FPC, ETC, (HP, DF) Al/Cu/VA n/a approx Climalife, France Solufluid Solar -25 C MPG ready FPC, ETC, (HP) Al/Cu/VA Greenway Neo Solar -30 C 1.3-propanediol ready FPC, ETC, (HP, DF) Al/Cu/VA Fragol, Zitrec LC MPG conc FPC Al/Cu/VA Zitrec L-25 MPG ready FPC Al/Cu/VA Fragoltherm W-PGA MPG conc FPC Al/Cu/VA Fragoltherm W-VR MPG ready ETC Cu/VA Osterwalder, Switzerland Coolant SOL high boiling glycols ready FPC, ETC, (HP, DF) Al/Cu/VA Pro Kühlsole, Pekasolar 100 MPG conc FPC, ETC Al/Cu/VA Pekasolar 50 MPG ready FPC, ETC Al/Cu/VA Sentinel, United Kingdom R100 MPG ready FPC, ETC Al/Cu/VA Staub & Co. Silbermann, Solarliquid L Konzentrat MPG conc FPC, ETC Al/Cu/VA n/a approx Solarliquid L gf -28 C MPG ready FPC, ETC Al/Cu/VA -28/-38 6 approx Solarliquid L gf -22 C MPG ready FPC, ETC Al/Cu/VA -22/-28 6 approx Solarliquid HT gf high boiling glycols ready FPC, ETC Cu/VA -24/-27 6 approx Sunex, Poland SL n/a conc FPC, ETC Al/Cu/SS Thermochema, Austria Powercool DC924-PXL MPG conc FPC, ETC, (HP) Al/Cu/VA High-temperature solar fluid MPG ready FPC, ETC Cu/VA DC923-H Tyforop, Tyfocor L MPG conc (40) FPC Al/Cu/VA Tyfocor L-eco MPG (RRM) conc (40) FPC Al/Cu/VA Tyfocor HTL MPG, high boiling glycols ready ETC, (FPC) 4 Al/Cu/VA Tyfocor LS MPG ready ETC, (FPC) 4 Cu/VA Tyfocor LS Arctic MPG ready ETC, (FPC) 4 Cu/VA Tyfocor LS Mediterraneo MPG ready ETC, (FPC) 4 Cu/VA Tyfocor G-LS MPG ready ETC, (FPC) 4 Cu/VA Wittig Umweltchemie, Glysofor Solar MPG, high boiling glycols conc (20) FPC, ETC Al/Cu/VA Glysofor Solar AF MPG, high boiling glycols ready FPC, ETC Al/Cu/VA Glysofor Solar HT MPG, high boiling glycols ready FPC, ETC Al/Cu/VA Table 1: Abbreviations: FPC = flate plate collector; ETC = evacuated tube collector; HP = heat pipe; DF = direct flow; Al = Aluminium; Cu = Copper; VA = stainless steel; MPG = mono propylene glycol; conc = concentrate; n/r = not recommended; RRM = gained from renewable raw materials Footnotes: 1 at 20 C; 2 in brackets minimum concentration [vol. %]; 3 only tested with Tyforop L and LS; 4 developed for ETC; 5 for flocculation point; 6 first flocculation point, second solidifying point; 7 mixing ratio 50 %; 8 for concentration 40 vol. % Source: company data means a secure supply and greater price stability, von Jeinsen said. The global Clariant group from Switzerland is also adding two new products to its range in the fall. Antifrogen Geo, which is based on monoethylene glycol and is designed for use in geothermal systems, will be sold as a concentrate and as a ready-to-use mixture in three versions. Clariant is also introducing Antifrogen Solar, making it the only company to introduce a new solar thermal product this year. The new antifreeze fluid to complement Antifrogen Sol HT is a ready-to-use mixture based on propylene glycol and provides frost protection down to -28 C. The corresponding concentrate is available under the name Antifrogen Solar Conc. Johannes Harder, Global Technical Application Manager for functional fluids at Clariant, emphasises the outstanding corrosion protection of the two new products as well as the free laboratory service for customers. Customers can submit fluid samples and have them analysed for antifreeze, reserve alkalinity, ph value, or individual inhibitors. Clariant can even help with specific problems such as searching for the cause of precipitation in the heating circuit. If zinc is found in the precipitation, for example, then this is an indication that there are galvanized pipes in the heating circuit; glycol-based antifreeze must not be used in this type of piping. If a customer is not sure whether a particular polymer material used in pipes or seals is compatible with the heat transfer fluid, then they can send a sample to Clariant to be analysed for free. Kilfrost UK has also introduced a new fluid for use in geothermal heat pumps: Kilfrost Geo. Although the data sheet does not disclose the ingredients that the 34 Sun & Wind Energy 4/2016

$Refraction index ph-value 1 [ml 0,1 N HCl] Buffer alkalinity Mixable n/a approx. 8 approx. 9 n/r n/a approx. 8 approx. 9 7 n/a n/a approx. 8 approx. 9 n/a approx. 1.401 approx. 9 4 yes 3 approx. 1.46 approx.$ 8 n/a MPG/n/r 1.378 7.5 up to 9.5 n/a n/r 1.382 9 > 20 n/r 1.401 approx. 8 n/a n/a Heat pump Under floor heating Boiler 1.431 9 4 yes 1.384 9 2 yes 1.380 up to 1.384 8.35 7.7 yes approx. 1.435 7.

8 n/a MPG/n/r 1.378 7.5 up to 9.5 n/a n/r 1.382 9 > 20 n/r 1.401 approx. 8 n/a n/a Heat pump Under floor heating Boiler 1.431 9 4 yes 1.384 9 2 yes 1.380 up to 1.384 8.35 7.7 yes approx. 1.435 7.

5 n/a n/a 1.378 8 8.6 > 6 Gelbin DC924-L 1.38 approx. 9 > 20 Powercool DC924-PXL 1.3792 8 7.5 up to 8.5 8 > 5 8 Tyfocor L-eco, others n/r 1.3792 8 7.5 up to 8.5 8 > 4 8 Tyfocor L-eco, others n/r 1.

4 Refraction index ph-value 1 [ml 0,1 N HCl] Buffer alkalinity Mixable n/a approx. 8 approx. 9 n/r n/a approx. 8 approx. 9 7 n/a n/a approx. 8 approx. 9 n/a approx approx. 9 4 yes 3 approx approx yes up to 9 3 no up to no Follow the Greenway Neo, the technological and environmentally friendly alternative up to 8.5 n/a MPG/n/r approx. 8 n/a MPG/n/r up to 9.5 n/a n/r > 20 n/r approx. 8 n/a n/a Heat pump Under floor heating Boiler yes yes up to yes approx up to 8.5 approx. 19 MPG approx approx. 8 approx. 9.5 MPG approx approx. 8 approx. 9.5 MPG approx up to 8.5 approx. 9.5 n/a Solar panel Hot water system n/a 7.5 up to 9.5 n/a n/a > 6 Gelbin DC924-L 1.38 approx. 9 > 20 Powercool DC924-PXL up to > 5 8 Tyfocor L-eco, others n/r up to > 4 8 Tyfocor L-eco, others n/r up to 8.5 > 9 no up to 10.5 > 20 LS Arctic, LS Mediterraneo, Tyfocor G-LS up to 10.5 > 25 TyfocorLS, LS Mediterraneo, Tyfocor G-LS up to 10.5 > 12 Tyfocor LS, LS Arctic, Tyfocor G-LS up to 10.5 > 20 Tyfocor LS, LS Arctic, LS Mediterraneo up to 8 3 MPG up to 8 3 MPG up to 8 3 no fluid is based on, it does show the kinematic viscosity curve at different temperatures compared to antifreeze fluids based on monopropylene glycol, ethanol and monoethylene glycol. According to the graph, Kilfrost GEO has a kinematic viscosity of 3.5 mm 2 /s at 0 C. The next highest comparison value in the graph on the Kilfrost data sheet is a fluid based on monoethylene glycol with a kinematic viscosity of just over 4 mm 2 /s at 0 C. The dynamic viscosity is not specified on the data sheet. According to the manufacturer, the fluid is non-toxic and is based on ingredients that have been approved by the US Food and Drug Administration (FDA). It has also been tested in accordance with ASTM D Thanks to the low viscosity of the fluid, the Kilfrost GEO data sheet promises users less loss of pressure, lower electricity costs for the pump and better overall efficiency. Eva Augsten Approved by: ANSES Belgaqua A full range of plant-based heat transfer fluids suited to Renewable energy Greenway Neo Solar to sustain solar thermal systems Greenway Neo Heat Pump to optimise the heat transfer Greenway Neo to protect underfl oor heating More infos: Solar Edition 35

5 Solar thermal Market Overview heat Transfer Fluids Heat transfer fluids for geothermal energy systems Manufacturer Product Antifreeze Delivery form Minimum concentration Classification 1 [vol %] Tmin [ C ] 2 according to GHS 2 Density [g/cm 3 ] 2,3 Refraction index 2 Aqua-Concept, Coracon KS 6 MEG conc GHS n/a Coracon KS 6 F-13 MEG ready GHS 07, GHS n/a Coracon WT 6N MEG conc GHS 07, GHS n/a Coracon WT 6N F-20 MEG ready GHS 07, GHS n/a Coracon WT 6P MPG conc none n/a Coracon WT 6P F-20 MPG ready none n/a Coracon Geko N MEG conc 10-5 GHS 07, GHS n/a Coracon Geko EF-10 MPG (RRM) ready none n/a Coracon Geko AF-8 ethanol ready - -8 none 0.98 n/a Clariant, Switzerland Antifrogen N MEG conc/ready n/a Antifrogen L MPG conc/ready none Protectogen N MEG conc/ready n/a Protectogen L MPG conc/ready none Climalife, France Solufluid Heat Pump -25 C MPG ready none Greenway Neo Solar -30 C 1.3-propanediol ready none Fragol, Zitrec MC MEG conc n/a - GHS 08 n/a n/a Zitrec M-10 MEG ready GHS Zitrec M-20 MEG ready GHS Zitrec M-35 MEG ready GHS Fragoltherm W-ECO MEG conc GHS Fragoltherm W-ECO-20 MEG ready GHS Zitrec LC MPG conc none Zitrec L-20 MPG ready none GHC Gerling, Holz & Co., Coolex N MEG conc/ready GHS 07, GHS Coolex L MPG conc/ready none Osterwalder, Switzerland Minoltherm ethanol ready none n/a Food Freeze MPG conc/ready none n/a approx Freeze Protection MEG conc/ready GHS 08 n/a approx Pro Kühlsole, Glykosol N MEG conc/ready - -8 GHS up to Pekasol L MPG conc/ready - -6 none up to Pekasol 2000 watery organic salt solution conc/ready none Staub & Co. Silbermann, Kühlsolekonzentrat N MEG conc 20-9 GHS 07, GHS 08 approx n/a Kühlsolekonzentrat Spezial VA MPG conc 20-6 none approx n/a Kühlsolekonzentrat N-Geo MEG conc 20-8 GHS 07, GHS 08 approx n/a Kühlsolekonzentrat Spezial-Geo MPG conc 20-7 none approx n/a Staubcosol BE gf -10 C ethanol ready none approx up to Staubcosol BE gf -8 C ethanol ready - -8 none approx up to Tyforop, Tyfocor MEG conc 20-9 GHS 07, GHS Tyfocor GE MEG conc 20-8 GHS 07, GHS Tyfo Spezial potassium carbonate ready GHS n/a Wittig Umweltchemie, Glysofor N MEG conc GHS n/a Glysofor L MPG conc none n/a Glysofor Terra MEG conc GHS n/a Glysofor Evo N MEG conc GHS n/a Glysofor Evo L MPG conc none n/a Glysofor Carbo alkali carbonate ready GHS 05, GHS Table 2: Abbreviations: MPG = mono propylene glycol; MEG = mono ethylene glycol; GHS = globally harmonized system of classification and labelling of chemicals; GHS 08 = health risks; GHS 07 = acute toxicity; GHS 05 = corrosive; RRM = gained from renewable raw materials, conc = concentrate (Kilfrost did not answer S&WE s request for information and is therefore not included in the table.) 36 Sun & Wind Energy 4/2016

ph-value 2,3 Specific thermal capacity [kj/kgk] 2,3 Buffer alkalinity [ml 0,1 N HCl] Mixable Dynamic viscosity [mpa*s] 3 8.0 up to 8.5 3.73 n/a n/a n/a 8.0 up to 8.5 3.62 n/a n/a n/a 8.

0 up to 8.5 3.83 n/a n/a n/a 7.4 up to 8.0 3.9 4 n/a 3.59 ONE FOR ALL THE SBS 2000 Flush, vent and fi ll your system easily 8.0 up to 9.0 3.9 4 n/a 5.95 7.0 up to 8.5 3.9 2.

98 n/a MEG (conditional) 3.51 8.3 up to 8.6 3.74 n/a MEG (conditional) 5.72 8.3 up to 8.6 3.36 n/a MEG (conditional) 9.66 8.7 up to 8.8 3.85 n/a MEG (conditional) n/a 8.

05 n/a MPG (conditional) n/a Designed to meet your requirements Sturdy and thermally resistant Usable for all solar, heating and heat pump systems Robust, smooth-running

5 up to 9.4 3.953 n/a n/a n/a 7.5 up to 9.0 n/a n/a n/a n/a 7.5 up to 8.5 n/a approx. 23 n/a n/a 8 up to 10 3.88 > 20 n/a n/a 8 up to 10 3.39 5 n/a n/a n/a 8 up to 9 3.

5 up to 8.5 n/a approx. 0.4 no n/a 7.5 up to 8.5 n/a approx. 0.4 no n/a PEKASOLar 50 DESIGNED TO PROTECT, PRESERVE AND CONSERVE YOUR SOLAR THERMAL SYSTEM!

5 Tyfocor 3.4 > 10 3.02 n/a no 3.69 7 up to 8 3.85 > 3 MEG n/a 7 up to 8 3.

6 ph-value 2,3 Specific thermal capacity [kj/kgk] 2,3 Buffer alkalinity [ml 0,1 N HCl] Mixable Dynamic viscosity [mpa*s] up to n/a n/a n/a 8.0 up to n/a n/a n/a 8.0 up to n/a n/a n/a 8.0 up to n/a n/a n/a 8.0 up to n/a n/a n/a 8.0 up to n/a n/a n/a 8.0 up to n/a n/a n/a 8.0 up to n/a n/a n/a 8.0 up to n/a n/a n/a 7.4 up to n/a 3.59 ONE FOR ALL THE SBS 2000 Flush, vent and fi ll your system easily 8.0 up to n/a up to n/a n/a 8.0 up to n/a n/a 7.5 up to n/a up to n/a up to 9.0 n/a n/a MEG (conditional) n/a 8.3 up to n/a MEG (conditional) up to n/a MEG (conditional) up to n/a MEG (conditional) up to n/a MEG (conditional) n/a 8.3 up to n/a MEG (conditional) up to n/a MPG (conditional) n/a Designed to meet your requirements Sturdy and thermally resistant Usable for all solar, heating and heat pump systems Robust, smooth-running wheels Versatile, powerful pump up to n/a MPG (conditional) up to approx. 4.5 n/a n/a 7.5 up to approx. 4.5 n/a n/a 8.5 up to n/a n/a n/a 7.5 up to 9.0 n/a n/a n/a n/a 7.5 up to 8.5 n/a approx. 23 n/a n/a 8 up to > 20 n/a n/a 8 up to n/a n/a n/a 8 up to Pekasol 50 (conditional) n/a 7.5 up to 8.5 approx n/a MEG n/a 7.5 up to 8.5 approx n/a MPG n/a 7.5 up to 8.5 n/a n/a MEG n/a 7.5 up to 8.5 n/a n/a MPG n/a 7.5 up to 8.5 n/a approx. 0.4 no n/a 7.5 up to 8.5 n/a approx. 0.4 no n/a PEKASOLar 50 DESIGNED TO PROTECT, PRESERVE AND CONSERVE YOUR SOLAR THERMAL SYSTEM! Heat transfer fluid on basis of propylene glycole for all types of collectors One product for all types of collectors! > > 10 Tyfocor GE 3.47 > > 5.5 Tyfocor 3.4 > n/a no up to > 3 MEG n/a 7 up to > 3 MPG n/a 7 up to > 3 MEG n/a 7 up to > 3 MEG n/a 7 up to > 3 MPG n/a 11 n/a n/a water n/a Footnotes: 1 only for concentrates; 2 for minimum concentration; 3 at 0 C; 4 at 20 C, 5 at concentration 27 % Source: company data pro KÜHLSOLE GmbH Am Langen Graben 37 D Düren Tel.: info@pekasolar.de Solar Edition 37

Low-Temperature Heat Transfer Fluids Newer Options

Low-Temperature Heat Transfer Fluids Newer Options Introduction Are you looking for the performance of an ethylene glycol-based system with the safety and toxicity performance of a propylene glycol-based