For most people in Florida, an Aquatherm swimming pool heat pump is the best choice for heating their pool, however not always. We sell thousands of solar systems a year to people who want no operating cost and don’t object to the appearance of the solar collectors on the roof. Heat pumps are more than 5 times as efficient as a gas heater however they generate heat slower. You can’t usually turn on a heat pump tonight and go swimming in the morning.
Rule of thumb is that you will gain around 1/2 a degree an hour with a properly sized unit under normal conditions in Florida. This is an average net gain after you factor in your heat loss of the pool during the hour. Weather conditions will greatly affect the temperature of your pool. A 5 MPH wind can double your heat loss. Heat output and efficiency of the unit increases as temperature and humidity rise. An average 500-gallon spa will gain around 10 degrees an hour under normal conditions.
There is little doubt a pool blanket will cut your heat loss by 75% or more. By cutting your heat loss your heat pump has to run less and cost less to operate. On our website, we will do an audit for you showing operating cost with and without a cover. There is an alternative to the plastic pool blanket. It is called “liquid pool blanket.” It puts a molecular film over the surface which is invisible to the eye. It is not as good as a plastic pool blanket however it can cut your heat loss by 30 percent or more.
Yes, excessive chemicals and extremes in PH can affect some heat pumps, however, nearly all heat pumps manufactured today have a titanium heat exchanger. Titanium is virtually bulletproof against pool water chemicals and we offer a 15-year warranty on those units. Bulletproof comes at a cost and the titanium units are substantially more expensive than the old cupronickel units. We have used cupronickel heat exchangers for over 10 years and have had little problems with them as long as they are installed properly and the pool water chemistry is kept in balance. Unfortunately, some pool owners don’t keep their pools in balance and that can cause a cupronickel heat exchanger to fail. When a cupronickel heat exchanger is breached it destroys the compressor as well and when pool water mixes with the freon gas, the entire unit is compromised.
For the most part yes. The heat pump absorbs heat from the air and at around 45 degrees Fahrenheit the discharge air from the heater is around freezing. Condensation, created by this heat transfer runs off the evaporator coil and if the coil is below freezing ice will form. If the coil is frozen there is no heat transfer and damage can be done to the compressor, so the unit automatically goes into a defrost mode around 45 degrees. Keep in mind if it is 45 degrees outside very few people are inclined to go swimming. We used to build a swimming pool heat pump with a feature called “hot gas defrost.” In the event the air coil would freeze up we would divert the hot gas, intended to heat pool water, back through the air coil to melt the ice. Considering the heat loss of the pool under those conditions and then only having the unit actually heating the pool water half the time adds up to wasting money. Proper sizing of the unit to do the job during the day eliminates the need for this feature.