Heat and Cool Pool Heat Pumps in Florida

A pool heat pump does not make heat, it moves it. A fan pulls warm, humid outdoor air across an evaporator coil, a refrigerant circuit concentrates that low-grade heat, and a titanium heat exchanger hands it to the pool water. A heat/cool model adds one part — a reversing valve — that lets the refrigerant run the other way. Now the exchanger pulls heat out of the water and the coil dumps it into the air. It is the same trick your home air conditioner uses, aimed at the pool instead of the living room.

Manufacturers give the capability different names. GulfStream marks it with a TA suffix; Hayward calls it Heat+Chill; Jandy calls the VersaTemp a Heat/Chill pump; Raypak uses an EHC part number for its heat/cool Crosswind V models; Pentair marks UltraTemp models H/C; Built Right appends H/C. They are all describing the same reversing-valve arrangement.

How the control behaves is worth knowing before you buy. A GulfStream TA offers two modes: heat/cool, which holds one setpoint and swaps between heating and chilling when the water drifts outside a deadband (two degrees by default), and cool-only, which simply chills to a setpoint. One is a thermostat for the pool; the other is an air conditioner with an on switch.

One limitation is nearly universal: cooling is for the pool, not the spa. GulfStream's installation manual states it plainly — the cooling feature is only for the pool. If your complaint is a spa that sits at 100°F in July because it shares water with the pool, a chiller on the pool circuit is not going to fix the spa.

Everywhere else in the country, a pool loses heat faster than an owner would like. Here, in July and August, the same physics works against you. A residential pool is a wide, shallow, dark-bottomed solar collector pointed at the sky for fourteen hours a day, and the ground around it has been warm for months.

The main way a pool cools itself is evaporation, and Florida humidity suppresses exactly that: muggy air already holds most of the water vapor it can carry, so less evaporates off the surface and less heat leaves with it. The same humidity that makes our heat pumps efficient in February — they extract heat from moisture as well as temperature, which is why the industry rates them at 80% relative humidity — is what keeps the pool warm in August. In our own work along the Gulf Coast the pools that generate this complaint are consistent: unscreened, unshaded, shallow, often dark-finished, frequently on a west-facing lot. Screened, shaded, deeper pools rarely need chilling at all, so it is worth knowing which of those two pools you own before spending money.

Most major manufacturers now publish at least one reverse-cycle model. These are the ones a Florida homeowner is most likely to be quoted, with the figures the manufacturers themselves publish:

Two things, and both are worth knowing before you sign. The first is heating capacity. Within one manufacturer's line, the heat/cool model is usually rated slightly lower than the heat-only version of the same size, because the reversing valve and the extra refrigerant plumbing are in the way. GulfStream's own spec sheet is the cleanest illustration: HE125-RA 118,000 BTU/hr against HE125-TA 115,000, and HE150-RA 138,000 against HE150-TA 135,000, all at the same test point. It is a small difference, roughly 2%, but it runs the wrong way for anyone buying the heat/cool model mainly for winter heating.

The second is money. A heat/cool model carries a real premium over the heat-only unit of the same size. We publish relative price tiers rather than prices, because installed cost moves with electrical work, pad work, plumbing and permits — but the ranking inside a line is always the same: heat-only is cheaper.

What it does not cost you is efficiency in heating mode. The TA and RA versions of a GulfStream carry the same published COP of 6.0, and the reversing valve sits idle whenever the unit is heating.

Heat pumps hold a temperature rather than chase one, and that is as true in cooling mode as in heating. GulfStream's manual gives the benchmark for heating: under ideal conditions — 80°F air, 80°F water, 80% humidity — a properly sized unit raises water temperature an average of about 1°F per hour. Cooling a pool works on the same order of magnitude, which means chilling is an overnight job, not an afternoon one.

That also tells you when a chiller works best: at night, when the air the fan dumps heat into is coolest. A unit fighting 95°F afternoon air has far less temperature difference to work with than the same unit at 3 a.m. And if the pump runs on a schedule, the cooling hours and the pump hours have to overlap — no heat pump moves heat through water that is not flowing.

The other number worth internalizing is how much capacity a heat pump loses as air temperature falls, which matters for the heating half of the year. Jandy publishes its VersaTemp at three test points, and the fall-off is instructive: the JRT2000R is rated 103,000 BTU/hr at COP 6.4 at 80/80/80, 96,000 BTU/hr at COP 6.1 at 80/63/80, and 62,000 BTU/hr at COP 4.1 at the low 50/63/80 point. A heat pump on a 50°F Florida morning is doing roughly 60% of its rated work. GulfStream states the same thing more simply: every HE model meets or exceeds a COP of 4.0 at the AHRI low test point.

Neither GulfStream nor most of its competitors publishes a cooling capacity or a minimum achievable pool temperature, so we will not print one. Hayward and Jandy are the exceptions among the lines above: Hayward states that its Heat+Chill models chill down to 40°F, and Jandy's JRT4001R manual states the heat pump can chill a small body of water, around 800 gallons or less, to 40°F — cold-plunge specifications rather than pool ones. In ordinary use, expect a reverse-cycle heat pump to take the top few degrees off a pool that has drifted into the high 80s or low 90s, and to hold it there, rather than to make it cold.

Electrically these are the same machines as their heat-only siblings. GulfStream's TA models run on 208-230V single phase with 37 to 40 minimum circuit amps and a 50 amp maximum breaker; Hayward's HP31405T is 230V with a 50 A recommended breaker and 70 A maximum overcurrent protection; Raypak's Crosswind V runs 208-230VAC. On older Florida panels, a dedicated 50 amp circuit is frequently the part of the job that surprises people.

Airflow is the other constraint, and it applies in both directions — a chiller rejects heat into the air just as a heater pulls heat out of it. GulfStream specifies 12 inches of clearance on each side and four feet above the unit, outdoor only, and its installation manual warns that enclosed or overhung locations recirculate the discharged air, cut capacity and may void the warranty on refrigerant components. A heat pump crammed against a wall under a soffit disappoints in both modes.

Two plumbing details matter as much as the electrical. Order: GulfStream's published sequence is pool pump, filter, heat pump, solar, then the chlorinator or salt cell, then the pool, with a check valve between the chlorinator and the heat pump — a salt cell upstream of any heater is a warranty problem. Flow: GulfStream asks for 30 to 70 GPM with 45-50 GPM optimal (20 GPM minimum on the smallest model) and Raypak publishes a 60 GPM maximum on the Crosswind V, so variable-speed schedules have to satisfy the flow switch during heating and cooling hours.

One last practical note: heat pumps produce condensation, and a lot of it — GulfStream states up to three gallons an hour, draining out of the base. That is normal and not a leak. A chlorine test strip on the puddle settles the argument, because condensation contains no chlorine and pool water does.

We talk customers out of the chiller version fairly often, and these are the usual reasons.

The honest test is simple: if your pool spends more than a few weeks a year above 90°F and you avoid swimming because of it, a heat/cool heat pump is the only equipment that actually fixes it, and the premium over a heat-only unit is small next to the cost of a pool you do not use. If that is not your pool, buy the heat-only model and spend the difference on a variable-speed pump or a cover.

We install and service both kinds throughout Sarasota, Manatee, Charlotte & Pinellas County, Florida, and we will tell you which one your pool needs before we quote it. The comparison content on this site is written for pool owners anywhere; the installation offer is local.