Next week start heat pump

[jeremycrook]

So this is my first "season" with my new pool, we were able to swim a few weekends last season but didn't quite understand how everything worked. So my question is with the heat pump, I have a Jandy JE3000TR (heater/chiller). From what I see next weeks temps will be in the mid 70's - 80's even upwards of 88*, so I am thinking to kick on the heatpump and swim. I have a solar cover, so I think I can get away with swimming early and not break the bank by keeping the cover on the pool in the evenings. My question is what do I do with the pool pump settings, I have a booster for the cleaner and have the main pool pump? Do I just need to turn the pump on to run 24/7, or does the heat pump kick on the main pump? From what I read the heat pump needs a min of 20 GPH so the water needs to be flowing, am I thinking this the correctly? If I do need to run the pump 24/7, I am now thinking of the SWG. It will be producing chlorine constantly, and I am assuming it will need to be turned off or the chlorine would skyrocket with the cover on.

 

[pooldv]

You've got all the right ideas there.

My SWG is on its own timer and I set it to run independently. So that I can run the pump as much as needed without making chlorine all the time. My pump is on a lot for solar standby/heating and leaf skimming. I just need to be careful to make sure that the SWG run times are always I side the pump powered run time window because you do not want the SWG on when the pump is not on.

Yes, the pump needs to be on for the heat pump to operate. If you have a variable speed pump find the lowest RPM that makes the heater happy and then run it 100-200 rpm faster than that.

I would only run the heat pump and the pump during the day right now. Two reasons, the heat pump efficiency increases a lot with ambient temp, especially if nighttime temps are below 60. Also, running your pump at night will cool the pool some because of the water running through colder plumbing, filter, etc. I reduced overnight temp loss by 1-3 degrees when I stopped running my pump at night. This also works the opposite when it is hot, running at night will help cool the pool off a bit.

I am only running solar right now to start heating my pool, with cover on. My pump is running 10a to 8p. I need to look at the forecast to see if it is time to turn on the heat pump.

 

[jtrovato21]

To add on to what has already been said, I recommend you set your heat pump to your desired temp and leave it there and leave it on for the season. If you are constantly turning it on and off and letting the pool cool down and then need to be heated back up again, you are going to spend a lot of money on electric to run that heat pump. It costs less to maintain it at the temp you want (if you're going to be using the pool consistently throughout the season), than it would to raise the temp to your desired temp each weekend.

 

[jeremycrook]

You've got all the right ideas there.

My SWG is on its own timer and I set it to run independently. So that I can run the pump as much as needed without making chlorine all the time. My pump is on a lot for solar standby/heating and leaf skimming. I just need to be careful to make sure that the SWG run times are always I side the pump powered run time window because you do not want the SWG on when the pump is not on.

Yes, the pump needs to be on for the heat pump to operate. If you have a variable speed pump find the lowest RPM that makes the heater happy and then run it 100-200 rpm faster than that.

I would only run the heat pump and the pump during the day right now. Two reasons, the heat pump efficiency increases a lot with ambient temp, especially if nighttime temps are below 60. Also, running your pump at night will cool the pool some because of the water running through colder plumbing, filter, etc. I reduced overnight temp loss by 1-3 degrees when I stopped running my pump at night. This also works the opposite when it is hot, running at night will help cool the pool off a bit.

I am only running solar right now to start heating my pool, with cover on. My pump is running 10a to 8p. I need to look at the forecast to see if it is time to turn on the heat pump.

OK, a few other questions/comments now. My SWG is wired directly into the pool pump (m/b not directly, but they work concurrently), I don't think I want to mess rewiring if I can get away with just running the heater during the day? I guess I can easily switch the SWG off if my Chlorine starts to get too high.

Second, the efficiency of the pump. How is this determined, or how can I understand this more? So on Jandy website I read that Output BTU is 137K, Output SRC BTU is 127K, and Output low ambient is 86K. I assume the high output is premium conditions and I have no clue what SRC means, and low ambient will be <60 degrees??? So running the pump at night will not break even with heat loss from piping, being cooler with non-efficient temps? That's depressing, I would have hoped it would raise temps but m/b not as much as daytime hours.

So currently with temps to be expected >70 next week with lows ~50-55, THE BEST BANG FOR MY BUCK will be run the pool 12 or so hours during the day, when the sun goes down stop running. All of this is with the cover on. I can manually adjust SWG as needed?

I need to research my pump, as I don't know if my Stealth pump is adjustable? If so running according to keeping heater happy will be best?

 

[Pool Tool]

For the SWG - it is powered at all times via the direct connection to the pump but it only runs based on the % run time you have it set at. Unless the TruClear doesn't have run time adjustment (?), it sounds to me to be wired correctly.

Can't help you on the heat pump, sorry.

 

[pooldv]

On your SWG, yes it is fine to just lower the output percentage and/or turn it off to keep your FC at the right level. I often run my pump 24x7 for leaf/debris skimming and I couldn't turn my SWG down enough to stop the FC from rising. It is common, and correct, for the SWG and pump to be wired to a timer so that the SWG can only be turned on when the pump is on.

Heat pump efficiency varies with outdoor temp. The warmer it is the more efficient it is. Efficiency means how close to rated output can it reach. Your heat pump is rated for 137k btu at some temp and humidity, maybe 80 degrees. They will usually have a rating at several different temps. The less heat in the air the less heat it can extract and the less it will heat the pool. It costs the same money to run the heat pump no matter the temp. What changes is the heat output. Thus, the efficiency drops. For easy math it is like this. 100k btu heat pump at 80 degrees, 80k btu at 60 degrees is 80% efficient at 60 degrees. It still uses the same amount of electricity to produce the 80k as it does the 100k.

Modern heat pumps can generate heat down into the 30s, 32 to 35 degrees. Older, more than 10 years ago, heat pumps didn't work well below about 50 degrees. Your heat pump will still heat your pool when it is 50 or 60 degrees outside. But, it won't generate as much heat for the electricity usage as it will when it is warmer outside. And running the pump at night through plumbing and filter exposed to colder outside air will also reduce overall heat gain. So, the question is can you generate enough heat only running during the day? Or do you need to also run at night?

There are times when we really want to swim and I run my heat pump all night and it will gain a degree or two. And other times when it is the same temp at 6 am as it was at 10 pm, which means it put heat into the pool because otherwise I would have lost a couple of degrees.

You have a relatively small pool and a relatively large heat pump, I think you will be able to keep it heated by running during the day and off at night.

My heat pump is 45k btu and my pool is 20k gallons. My heat pump takes about 3.7 hours to heat my pool 1 degree. Yours should be able to heat more than 1 degree per hour because your pool is half the size and your heat pump is more than twice as big. Keep some notes and you'll start to see some trends in your pool for heat loss and heat gain.

 

[jeremycrook]

On your SWG, yes it is fine to just lower the output percentage and/or turn it off to keep your FC at the right level. I often run my pump 24x7 for leaf/debris skimming and I couldn't turn my SWG down enough to stop the FC from rising. It is common, and correct, for the SWG and pump to be wired to a timer so that the SWG can only be turned on when the pump is on.

Heat pump efficiency varies with outdoor temp. The warmer it is the more efficient it is. Efficiency means how close to rated output can it reach. Your heat pump is rated for 137k btu at some temp and humidity, maybe 80 degrees. They will usually have a rating at several different temps. The less heat in the air the less heat it can extract and the less it will heat the pool. It costs the same money to run the heat pump no matter the temp. What changes is the heat output. Thus, the efficiency drops. For easy math it is like this. 100k btu heat pump at 80 degrees, 80k btu at 60 degrees is 80% efficient at 60 degrees. It still uses the same amount of electricity to produce the 80k as it does the 100k.

Modern heat pumps can generate heat down into the 30s, 32 to 35 degrees. Older, more than 10 years ago, heat pumps didn't work well below about 50 degrees. Your heat pump will still heat your pool when it is 50 or 60 degrees outside. But, it won't generate as much heat for the electricity usage as it will when it is warmer outside. And running the pump at night through plumbing and filter exposed to colder outside air will also reduce overall heat gain. So, the question is can you generate enough heat only running during the day? Or do you need to also run at night?

There are times when we really want to swim and I run my heat pump all night and it will gain a degree or two. And other times when it is the same temp at 6 am as it was at 10 pm, which means it put heat into the pool because otherwise I would have lost a couple of degrees.

You have a relatively small pool and a relatively large heat pump, I think you will be able to keep it heated by running during the day and off at night.

My heat pump is 45k btu and my pool is 20k gallons. My heat pump takes about 3.7 hours to heat my pool 1 degree. Yours should be able to heat more than 1 degree per hour because your pool is half the size and your heat pump is more than twice as big. Keep some notes and you'll start to see some trends in your pool for heat loss and heat gain.

OK. So I think my game plan will be to see if I can get the pool up to operating temp ~83* lets say next Wednesday when it appears to start a warming trend. I then will check how much heat is lost during the night hours without the pump on, and vice versa. I would like to see or check how much energy was used at night to keep the heater running. I guess I could do the same thing by reading my electric meter operating the heater one night and not operating the heater one night? Tracking how cold it dips as well might be useful data...