If you have a swimming pool which is located in the shade, is too cold for swimming during the summer season, you have a central Air-conditioning or a Heat pump system,  you have considered heating your pool with natural gas, propane or fuel oil., then why not consider alternative heating of your pool from the waste heat of your air conditioning.

    Your air conditioner or heat pump (in cooling mode) takes heat from the inside of your house and dumps it outside. If you can recapture this heat, it can be dumped into a swimming pool. This is done by installing a small water-to-refrigerant heat exchanger. The advantage of this, is that the system will perform better even on the hottest days therefore reducing electrical load and enhancing cooling.

    When compared to the cost of running a natural gas, propane or oil fired pool heater, this system will win every time. When compared to the cost of installing and piping a conventional heater the costs are less..

    Performance: Depending on the size of your pool, the output of your a/c unit and the outdoor temperature, you can expect to pick up 1 to 3 degrees F per day and should extend the season by at least one month later and possibly two months earlier.

Cooling performance may not be very noticeable, but can make the difference on a hot day. Electrical consumption will be noticeably less, especially on hot days when it would be highest on an air cooled (conventional) system.

    Additional equipment: water to refrigerant heat exchanger for transferring heat from a/c system to pool water. Piping to run from pool filter system to water to refrigerant heat exchanger.
The Indoor coil should be changed to one that can accommodate a TEV (thermostatic expansion valve) if it doesn't already have one. This change will improve cooling performance and prevent coil icing when the pool water is cold. Pressure safety controls are mandatory in case of inevitable water flow failure or indoor coil icing.

    Costs: Basic system; where the pool filter is right next to the outdoor unit (straight air-conditioning only) and the indoor coil does not need to be changed in any way, existing unit already has pressure controls, compressor does not need a start kit (scroll compressors do not need start kits)  and no indoor work needs to be done.
$1800 US (within 20 miles of Washington dc. or Baltimore md.)

    Standard system; where the pool filter is right next to the outdoor unit (straight air-conditioning only),  the indoor coil must be changed to one that will accommodate a thermostatic expansion valve, pressure controls must be added and the unit requires a start kit
$2500 US (within 20 miles of Washington dc. or Baltimore Maryland.)
$2200 if the coil only needs the addition of a thermostatic expansion valve.
 
    Reversing system; same as the standard system but a reversing valve is added to facilitate the system to "revert" to air cooled mode when the pool temperature reaches a set point. This system is quite complex because it requires a reversing valve, refrigerant receiver, two check valves, extra refrigerant piping, relays, wiring, thermostat for pool water. This system is recommended when two or more units are modified to assure that the pool doesn't overheat in hot weather. $3000 (within 20 miles of Washington Dc. or Baltimore maryland.)
$2700 if the indoor coil only needs the addition of a thermostatic expansion valve. A deposit of $500 is required to secure materials.

    Indoor system; everything included in the Standard system where the pool filter is located in the basement or a vault near the indoor section and the outdoor unit is within 15 feet of the filter pump.
    In this system the heat exchanger will have to be supported from the ceiling or hung on a shelf and the water piping will be pvc pipe integrated into the filter system. Since these quarters are usually tight it will require more labor but system will not have to be drained in the winter.
Subtract $350 if the indoor coil does not have to be changed
$2500 US (within 20 miles of Washington dc. or Baltimore md.)

    Remote system; everything included in the indoor system but the pool filter is located over 50 feet from the outdoor unit because a trencher will have to be used to bury the pipes to bring filter water to the refrigerant heat exchanger or in some cases the refrigerant lines can be extended.
Subtract $350 if the indoor coil does not have to be changed
at least $2100 US (within 20 miles of Washington dc. or Baltimore md.)

Heat pump systems, systems over 4 tons, multiple systems and other modifications that require extra controls and piping will significantly add to the cost of the system.
    Options: Add hot water recovery to the refrigeration portion only at time of installation add $400.00, Add pump cycling controls so the pool pump can shut off durning the times when air conditioning in not needed or the pool is hot enough with the "reversing system". Manditory if the pool pump is used on a timer. $200.
 These prices are negotiable and will be revised. While they may seem high modifying the refrigeration system and pool piping can be a very grueling task. the same as field installing a commercial refrigeration system.


Frequently asked Questions:
Q: how hot will my pool get?
A: Depending on the weather and the size of the pool in relation to the building and if a cover is used,  the pool can get as hot as the mid 90s even to reach 100 degrees but will loose heat so fast with the cover off that it will be limited to the low 90s.

Q: What do I do I do in winter?
A: .The system will have to be drained in the usual manner and any additional piping will have to be drained or blown out with air. Indoor systems do not have to be drained.

Q: Will my air-conditioning work if my pool filter is not working?
A: No it will not but many commercial systems use devices called "cooling towers" that are similar in operation to this system and must be put in and out of service each year. The exception is the "reversing unit"

Q: My system is new, will this system hurt my present system or void any warranties?
A: This system when properly installed will improve the performance of your system but will most likely void any manufactures warranties. However except for the compressor most items are of nominal cost and can be fixed by us. If a compressor does fail in the warranty period we will most likely be able to get the warranty honored.

Q: My system is very old can this modification be done?
A: Yes, we have successfully modified a system that was 25+ years old and by changing the indoor coil we have improved the efficiency of the system to a level that is better than some new systems.

Q: I all ready have a gas or oil fired heater can this system help?
A: This system can help by saving money on fuel once the pool has reached a decent temperature. A fossil fueled system is nice to quickly bring the pool up to temperature but is a waste when the air-conditioning will provide free heat. We can set the controls so that the fueled heater will not run when the air-conditioning is running.

Q: I like a cold pool because I do laps and don't stay in very long?
A: This system is not for you!

Q: I have a very large pool will this system help?
A: If the pool is very large (surface area) and deep then this system will help but it will be limited in what it can do. You may need to consider adding solar collectors to boost the temperature of the pool.

Q: My system has given me lots of problems, will these problems go away?
A When we make the modifications, we will go over every inch of your system and any pre-existing problems can be corrected or discovered. One system we discovered that a metering device was left out since day 1 (25+ years), when we were done the system worked better than new. It produced so much condensate that it flooded the customers stairwell that wit the old system just had a trickle.

For more information please contact us:


To read about pool looses and how a solar cover will help
To read about the hot water recovery system
  Written By:  Scott Meenen of:
G&S MECHANICAL SERVICES.
Specializing in Mechanical, Controls and Electrical Modifications Of
Heating, Air-conditioning, Refrigeration, Cold storage,
Ice Production and Food preservation.
Anything having to do with Heat and Energy.
Serving MD, DC, and Northern VA.
Contact us by pager: 1-877-467-2914 (most reliable)
Page us by e-mail 4103560613.3732505@pagenet.net 240Chrs max.
Email us at: jsmeenen@toad.net

This text written by: Scott Meenen * G & S Mechanical


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