Apricus Solar Water Heating System Installation and Operation ...

3.32. Heat Transfer FluidsApricus Solar Collector Installation & Operation Manual - USAa) In cold regions, a closed loop system using a heat transfer fluid should be installed.b) There are several types of heat transfer fluids commercially available, each with different properties. Thefollowing table provides a summary of key features of common fluids with water as base comparison.Please refer to detailed data files offered by each manufacturer. Apricus makes no claims on theperformance of the products listed below and the names and types are only used as examples.PlainWaterWhitlamSolar Hi-TempClariantAntifrogen SOL HTDowDowfrostDowDowfrost HDType of FluidWaterGlycerinebaseHigher Glycolswith InhibitorsPropyleneGlycol withInhibitorsPropyleneGlycol withInhibitorsHigh Temp Stability Excellent Excellent Excellent Poor ModerateViscosity atFreezingTemperaturesPressure Drop atFreezing TempsExcellent Poor Moderate Moderate ModerateLow High Moderate Moderate ModerateSpecific Heat High Poor Moderate Moderate ModerateThermalConductivityHigh Moderate Low Low ModerateNon-toxic* Yes Yes Yes Yes YesFDA GRAS Rating Yes Yes No Yes No*Fluids that are not rated FDA Generally Recognized As Safe require a dual wall heat exchanger, and may also needleak detection. In order to be used with a single wall heat exchanger the heat transfer fluid must be GenerallyRecognized As Safe. Always check the MSDS of the heat transfer fluid to ensure that the right type of heat exchanger isbeing used.c) When diluting a heat transfer fluid for use in a closed loop solar system always follow manufacturersguidelines.Copyright 2011 – Apricus Inc Doc: A7-05.4.1.4-PB-1.9 Page 39 of 126