Springtime Energy Savings with Geothermal Pool Heating
Are you considering extending your swimming season by installing a pool heater? Pool heaters are a great idea for both residential and community pools. They allow swimmers to take a nice, relaxing dip in the pool even on the coldest of days.
Spring is here, and the cooling season is quickly approaching. Thousands of pools around the country that have been decommissioned for the (very) cold winter, and are likely to stay that way well into June, unless some type of pool heating is done. All of the appliances in your home (and office) create heat and are potential source of energy that can heat domestic hot water, spas, or pools. With standard air source heat pumps, all of that heat generated inside your home typically goes up to the return air ductwork and ultimately is exhausted through your outside condenser unit. Like geothermal home heating and cooling systems, geothermal pool heat pump systems bring your swimming pool in harmony with nature, while providing the unmatched energy efficiency. They do that by working in concert with the stable earth temperatures to provide heating for you pool throughout your desired swimming season. They do that by working in concert with the stable earth temperatures to provide heating for you pool throughout your desired swimming season.
Solar is the most earth friendly and renewable source for pool heating, but is dependent upon cooperation of the weather. Cloudy and cool days can mean a cold pool. Fossil fuel heating of pools is an old favorite. First cost is relatively low, but that comes at a higher price environmentally and monetarily as you move forward. In addition to high costs for propane and other fuels, there are safety issues when fossil fuels are used as in this unfortunate story of carbon monoxide poisoning from pool heater, March 21st in the LA Times. Electric resistance heating uses raw electricity to warm heating elements over which the pool water passes (like an electric water heater) providing a clean and safe pool heating alternative, but it can be extremely expensive. Using the Coefficient of Performance (COP) rating system (used internationally) for heating appliances, electric heating has a COP of 1.0, meaning that 1 unit of heat is provided for each unit of electricity, a one-to-one ratio, or 100% efficient in the COP rating system. Air source pool heat pumps are environmentally friendly and use a renewable energy source, pumping heat out of the ambient air into your pool. However they too rely somewhat on cooperative weather conditions, that is, air temperatures being warm enough to facilitate efficient extraction of heat to transfer to the pool. The efficiency of these heat pump are in the 3.0 COP ranges (300% efficient).
Air source pool heat pumps are environmentally friendly and use a renewable energy source, pumping heat out of the ambient air into your pool. However they too rely somewhat on cooperative weather conditions, that is, air temperatures being warm enough to facilitate efficient extraction of heat to transfer to the pool. These heat pump efficiencies are in the 3.0 COP ranges (300% efficient). For swimming pool and spa heating, the best scenario is attained with a geothermal pool heat pump, pulling heat from a dependable, steady and renewable energy source; the earth. Geothermal heat pumps are about 5.0 COP (500% efficient). Outside, temperatures fluctuate with the changing seasons, but underground temperatures don’t change nearly as dramatically, thanks to the mass of the earth. 4 to 6 feet below the ground, the temperature remains relatively constant year round (about 50F to 75F in the US). A geothermal pool heating system, which can work in tandem with your geothermal home heating and cooling system, and typically consists of pool heat pump and a buried system of pipes called an earth loop, and/or a pump to reinjection well. This geothermal loop can be shared between the home heating and cooling, and pool heating systems.
One of the wonderful benefits that you can get only from geothermal HVAC systems is the ability to channel and use this waste heat energy. That’s because unlike the widely used air sourced heat pumps (those that have an outside condenser that discharges waste heat), geothermal discharges the heat through a liquid heat exchanger. The heat is entrained in the discharge water line. Most manufacturers of geothermal heat pumps even have a factory installed hot water generator. This option gives you two extra connections labeled DHW (Domestic Hot Water) In and Out. The plumber just ties in your current hot water tank, and the geothermal heat pump can do the rest. You might be surprised to know that there are thousands of geothermal heated pools around in the US. There is a good chance that the local YMCA or community pool already has geothermal. Wouldn’t you just love to heat your pool with your toaster, hair dryer, computers, and all that heat radiating from your lights and clothes dryer? Channel it where you want it with a geothermal system!