Spa Heat pump for Arizona

Blueice89

Well-known member
Dec 13, 2019
51
Gilbert Arizona
We are constructing our pool and initially I chose heat pump Aqualcal 166k for Spa/Pool since it can serve both.
166,000 BTU

Our pool is 20k gallon, VSP all Hayward products. SWG.

I was wondering have many people done okay with Heat Pump? Our weather is mostly sunny, desert, dry and lot of hot days.
To me it seems it would be okay.

We do not have gas lines / natural gas, and the cost of propane scares me.
I am thinking maybe someday if this doesn't work how I intended I could add a gas heater.

We do have solar, so electricity no matter what it is would be what I favor.
Our power is dirt cheap like 3-6cents per kwH , and just have to ensure to manage demand, which I can do via solar panels and batteries.
 
A 166K HP will add 1 degree an hour to your 20K gallon pool. You will need to see how much you need to run your pump and your HP to maintain the temperature you want. You will also learn how long it takes to heat your spa to desired temperature and how long before you plan to use the spa you need to get the heater going on it.

Having a pool cover will lower evaporation and retain heat overnight.
 
We are constructing our pool and initially I chose heat pump Aqualcal 166k for Spa/Pool since it can serve both.
166,000 BTU

Our pool is 20k gallon, VSP all Hayward products. SWG.

I was wondering have many people done okay with Heat Pump? Our weather is mostly sunny, desert, dry and lot of hot days.
To me it seems it would be okay.

We do not have gas lines / natural gas, and the cost of propane scares me.
I am thinking maybe someday if this doesn't work how I intended I could add a gas heater.

We do have solar, so electricity no matter what it is would be what I favor.
Our power is dirt cheap like 3-6cents per kwH , and just have to ensure to manage demand, which I can do via solar panels and batteries.

I'm running this exact model heat pump on a 20K pool right now in Gilbert, AZ. If you want to keep the water at 80+ degrees right now in the winter, this pump will not do it reliably. A heat pump can only move heat ,it doesn't burn a fuel to liberate heat, that's why its so much cheaper to run than an actual heater.. The problem is our air contains very little enthalpy (total heat) in the winter, so the pump can't move any into the pool.

I'm not sure if it's the heat pump itself or the intellicenter controlling it, but it will not attempt to heat until the air temp is about 55 degrees. I think this is probably because as soon as you try to suck heat out of 55 degree air, when the humidity is so low, the temp of the air around the coils in the heat pump drops to freeze up levels.

Right now we aren't swimming so I'm just using the heat pump to keep the pool water at 65 degrees so the SWG runs. Only takes a few hours a day of run time to do that and I don't have to dose LC. Pool usually drops to about 60-63 overnight depending on the low temp. I don't have a cover.

We are lucky here with pretty cheap power. I buy some community solar so I pay about $9c/KWH year round, net. The pump draws about 6 kW so even running 24/7 the cost is about $13/day.

In the later part of October and early Nov last year when the nighttime temps were still over the mid 50s, we were able to keep the pool at 85 for swimming, but it ran nearly all the time to do that.
 
Nice I am in Gilbert as well. How do you think the heat pump would do for a spa ?
Is the performance to a point where you thought about adding a gas heater booster ?

I'm running this exact model heat pump on a 20K pool right now in Gilbert, AZ. If you want to keep the water at 80+ degrees right now in the winter, this pump will not do it reliably. A heat pump can only move heat ,it doesn't burn a fuel to liberate heat, that's why its so much cheaper to run than an actual heater.. The problem is our air contains very little enthalpy (total heat) in the winter, so the pump can't move any into the pool.

I'm not sure if it's the heat pump itself or the intellicenter controlling it, but it will not attempt to heat until the air temp is about 55 degrees. I think this is probably because as soon as you try to suck heat out of 55 degree air, when the humidity is so low, the temp of the air around the coils in the heat pump drops to freeze up levels.

Right now we aren't swimming so I'm just using the heat pump to keep the pool water at 65 degrees so the SWG runs. Only takes a few hours a day of run time to do that and I don't have to dose LC. Pool usually drops to about 60-63 overnight depending on the low temp. I don't have a cover.

We are lucky here with pretty cheap power. I buy some community solar so I pay about $9c/KWH year round, net. The pump draws about 6 kW so even running 24/7 the cost is about $13/day.

In the later part of October and early Nov last year when the nighttime temps were still over the mid 50s, we were able to keep the pool at 85 for swimming, but it ran nearly all the time to do that.
 
Nice I am in Gilbert as well. How do you think the heat pump would do for a spa ?
Is the performance to a point where you thought about adding a gas heater booster ?
I really don't know how well it would work even with a small volume of water. A cover would help a lot, but you're still going to be limited, in the winter, to running when the air temp is high enough to avoid freeze up. It would probably work in a humid area like FL, but not in the dry desert.

Unfortunately, where the pool is there is no nat gas and since I don't live by the pool, I don't want to deal with the hassle of propane. But, really, its too cold for my family to swim now anyway so, no, I haven't considered adding a backup heater.

If you really want to be able to raise a spa to 104 in a couple of hours in winter, or something like that, I don't believe the heat pump will do that for you.
 
I really don't know how well it would work even with a small volume of water. A cover would help a lot, but you're still going to be limited, in the winter, to running when the air temp is high enough to avoid freeze up. It would probably work in a humid area like FL, but not in the dry desert.

Unfortunately, where the pool is there is no nat gas and since I don't live by the pool, I don't want to deal with the hassle of propane. But, really, its too cold for my family to swim now anyway so, no, I haven't considered adding a backup heater.

If you really want to be able to raise a spa to 104 in a couple of hours in winter, or something like that, I don't believe the heat pump will do that for you.
When do you anticipate being able to use heat pump once our lows are greater than 55 so like March April?
 
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