Closed Loop Antifreeze Solar Water Heating System

All water heaters waste heat energy even when the burner is off and the unit is sitting idle between heating cycles.

Closed loop antifreeze solar water heating system. Hydronic heating systems must be filled with water to provide the heat transfer fluid htf that makes them work. Glycol or some equivalent antifreeze fluid fills. Most new solar homes feature a variation of one kind or another. In the case of the closed loop solar heating system the htf is typically a mixture of water and propylene glycol.

Closed loop solar water heater systems sometimes referred to as anti freeze or glycol systems include the heat collectors insulated piping a circulating pump an expansion tank a hot water storage tank a heat exchanger solar fluid usually a solution of water and nontoxic propylene glycol antifreeze a controller valves and gauges. A special water heater tank incorporating a heat exchanger works in conjunction with one or more flat plate roof mounted collectors. If freeze protection is an issue than a closed system with anti freeze is a good idea. Heat exchangers in the storage tank eliminate a pump but make eventual tank replacement more.

Covers closed loop antifreeze systems and drainback systems. Propylene glycol and the new bio green are common antifreeze materials we have several options for exchanging the heat to the clean domestic hot water. In systems that use other types of heat transfer fluids such as glycol an anti freeze scaling can occur on the surface of the heat exchanger that transfers heat from the solar collector to the domestic water. The down side is two heat sources.

Installation basics for solar domestic water heating systems chuck marken and ken olsen. Closed systems are often used in second homes or primary residences in areas prone to long power outages. The process of filling the plumbing system with this antifreeze while purging all the air out must be done systematically and in the right order. Of closed loop anti freeze sdhw systems hereinafter referred to as closed loop sys tems.

42 home power 95 sdhw. Lots on installation detail. Very good articles on selecting the components for a closed loop solar hot water heating system suitable for cold climates. Installation basics for sdhw systems in hp94 covered aspects of installation common to most solar water heating installations such as collector location and mounting pipe runs soldering and insulation and the control system.