Here’s an idea for harvesting waste energy in a naturally synergistic combination. Many people who have air conditioners have swimming pools. Both take energy: one to cool, one to warm. Could you make use of the waste heat that your air conditioner generates as a byproduct when it cools your home – to warm your pool?
By recovering the heat exhausted, wouldn’t you then get two outputs from one input of energy? Air conditioning and hot water, from one energy input. If you could, that would cut your A/C carbon footprint in half.
Instead of just venting your air conditioner, adding to the heat island effect, heat recovery units could be inserted between your air conditioner and your water heater could tap that waste heat to warm the pool using a closed loop heat exchange (to keep the pool water separate) heating water to warm your swimming pool for free.
Several companies are already using heat recovery to create hot water for inside the home, like Zero Energy Water Heating Systems. Another, Heat Harvester claims that using their system, a house running a 5 ton air conditioner could generate up to 40 gallons of up to 140 F water an hour.
The savings seem considerable. A white paper on the likely energy savings from heat recovery units attached to A/C or refrigeration units cautions that if the unit produces too much hot water, the excess capacity might get wasted, reducing energy savings, or conversely, that when you don’t need A/C, this heat recovery will recover no heat, making no free hot water. Well, oh dear. Better put that idea away.
But better to save that energy only during hot weather than never save it at all. And as for the worry about too much heat, here’s an idea. It takes a tremendous amount of hot water to heat the average swimming pool to a comfortable 83 degrees.
Venting the heated water into a much larger “holding tank” than your hot water heater – such as a swimming pool – should take care of that worry. Even on hot days you typically need warm water to take the chill off a swimming pool. I doubt that an average sized home running air conditioning could ever generate enough heat to overheat an entire swimming pool.
I know we have a lot of tech types reading here. I’d be interested to hear from someone who is engaged in swimming pool heating, on this question. So, could an air conditioner heat a swimming pool? You tell me.