Variable Speed Pump with Heater

[Enrico_S]

Hi,

First post here. I hope this was the right place to post this.

I have a 15' above ground pool. I have a 1.5HP Hayward Matrix Variable Speed Pump (SP56152ET). I normally run it at 1.5HP for 6 hours and 18 hours at 1/6HP. I've just ordered a 110v Duratech SUN08 heat pump that has a flow requirement of between 17.6 and 52.8gpm, and the digital display indicates adequate flow. I'm going to install the heater after my filters and before my salt cell, and have a diverter valve going to the heater and probably a check valve after the heater, but before it gets to the main return. All of my piping is 1.5".

What I'm currently planning to do is set the appropriate flow on the diverter valve when the pump is running at 1.5HP, and hopefully I have enough flow when it's at 1/6HP. I'm concerned that if I try to set the appropriate flow at 1/6HP, I'd ruin the heater if I forgot to adjust the diverter when it switched to 1.5HP. I also don't want to be adjusting the diverter twice a day. My pump does not have the ability to run at low speed 24hr. It's only 24hr high, 18 high/6 low, 12 high/12 low, or 6 high/18 low.

Does anyone have any other ideas that doesn't include automation? Does anyone know of a pool rated pressure reducing valve or a valve that I can set the rate of flow that I want through it and above that will be diverted and if it's less it full goes through?

Thank you in advance!

 

[1poolman1]

Hi,

First post here. I hope this was the right place to post this.

I have a 15' above ground pool. I have a 1.5HP Hayward Matrix Variable Speed Pump (SP56152ET). I normally run it at 1.5HP for 6 hours and 18 hours at 1/6HP. I've just ordered a 110v Duratech SUN08 heat pump that has a flow requirement of between 17.6 and 52.8gpm, and the digital display indicates adequate flow. I'm going to install the heater after my filters and before my salt cell, and have a diverter valve going to the heater and probably a check valve after the heater, but before it gets to the main return. All of my piping is 1.5".

What I'm currently planning to do is set the appropriate flow on the diverter valve when the pump is running at 1.5HP, and hopefully I have enough flow when it's at 1/6HP. I'm concerned that if I try to set the appropriate flow at 1/6HP, I'd ruin the heater if I forgot to adjust the diverter when it switched to 1.5HP. I also don't want to be adjusting the diverter twice a day. My pump does not have the ability to run at low speed 24hr. It's only 24hr high, 18 high/6 low, 12 high/12 low, or 6 high/18 low.

Does anyone have any other ideas that doesn't include automation? Does anyone know of a pool rated pressure reducing valve or a valve that I can set the rate of flow that I want through it and above that will be diverted and if it's less it full goes through?

Thank you in advance!

At high speed your heater should be able to handle the flow from your pump.

 

[mas985]

Welcome to the forum!

First, it is unlikely that the Matrix will produce more than 53 GPM going through a heat pump and all 1.5" plumbing so I think you are safe.

Some heat pumps use something like this for the bypass:

Pentair Water Bypass Check Valve - R172305 - INYOPools.com

Water Bypass Check Valve - Pool & Spa Parts

www.inyopools.com

It opens when the pressure (i.e. head loss) gets too high through the HP.

The downside is that it creates a lot of head loss reducing efficiency.

But again, I don't think you need it.

 

[Enrico_S]

Welcome to the forum!

First, it is unlikely that the Matrix will produce more than 53 GPM going through a heat pump and all 1.5" plumbing so I think you are safe.

Some heat pumps use something like this for the bypass:

Pentair Water Bypass Check Valve - R172305 - INYOPools.com

Water Bypass Check Valve - Pool & Spa Parts

www.inyopools.com

It opens when the pressure (i.e. head loss) gets too high through the HP.

The downside is that it creates a lot of head loss reducing efficiency.

But again, I don't think you need it.

Thanks for the info.

Do you think there would be enough flow at low speed? I was thinking of putting a flow meter in the return line, but I don't really want to spend over $200 to check something basically once.

 

[mas985]

Do you think there would be enough flow at low speed?

Hard to say. It depends on the head loss in the HP and the filter as well as the rest of the plumbing. But it would have to be pretty bad to not reach 17 GPM.

What is the make model of the filter?

Is there only a single suction/return port?

How long are suction/return lines to/from the pool?

 

[1poolman1]

Thanks for the info.

Do you think there would be enough flow at low speed? I was thinking of putting a flow meter in the return line, but I don't really want to spend over $200 to check something basically once.

You don't actually have a variable-speed pump, but a 2-speed pump with an attached timer. It appears that it is only available in that configuration in the Canadian market.
You may find that the low speed is enough to run the heater, but that's something that you will have to try and if not there is nothing to be done but run the pump on the high speed to get the heater to work.

 

[Enrico_S]

Hard to say. It depends on the head loss in the HP and the filter as well as the rest of the plumbing. But it would have to be pretty bad to not reach 17 GPM.

What is the make model of the filter?

Is there only a single suction/return port?

How long are suction/return lines to/from the pool?

I have a Hayward Xstream 150 Filter (CC150Can) with a Nature2 Purifier. Single suction/return.
About 9 feet of pipe from the skimmer to the pump, about 2 feet between the pump and filter, a foot between the filter and purifier, and about 17 between the purifier and salt cell/return.
So lets say about 30 feet of pipe total.

A couple of pictures for context.

Appreciate all your help.

 

[Enrico_S]

You don't actually have a variable-speed pump, but a 2-speed pump with an attached timer. It appears that it is only available in that configuration in the Canadian market.
You may find that the low speed is enough to run the heater, but that's something that you will have to try and if not there is nothing to be done but run the pump on the high speed to get the heater to work.

Yeah, I was searching to see if someone had posted a similar issue, and I kept reading about variable speed pumps, and I just typed that in by accident. But yes, it is a two speed pump with timer.

And yes, I am in Canada.

 

[mas985]

With the heat pump inline, on high speed the flow rate should be around 44 GPM and low speed 22 GPM with a clean filter. If the estimate is correct, filter pressure should be 19-20 PSI on high speed.

Without the heat pump, high speed flow rate is 48 GPM, low speed 24 GPM with high speed filter pressure 17-18 PSI. Let me know if that filter pressure is pretty close to what you are seeing now.

 

[1poolman1]

I have a Hayward Xstream 150 Filter (CC150Can) with a Nature2 Purifier. Single suction/return.
About 9 feet of pipe from the skimmer to the pump, about 2 feet between the pump and filter, a foot between the filter and purifier, and about 17 between the purifier and salt cell/return.
So lets say about 30 feet of pipe total.

A couple of pictures for context.

Appreciate all your help.

Nice to see an above-ground pool with a proper equipment pad.
Many years ago Nature 2 offered a free item like yours if we went to their school to learn to use them. I went, got the mineral dispenser, installed it, went through three refills then cut it out of my system as I saw nothing different about my water. Much younger then and willing to experiment with stuff. Just a suggestion that you may not need it and it is just an added cost and restriction to flow.

 

[Enrico_S]

With the heat pump inline, on high speed the flow rate should be around 44 GPM and low speed 22 GPM with a clean filter. If the estimate is correct, filter pressure should be 19-20 PSI on high speed.

Without the heat pump, high speed flow rate is 48 GPM, low speed 24 GPM with high speed filter pressure 17-18 PSI. Let me know if that filter pressure is pretty close to what you are seeing now.

Right now, on high, it's around 16psi, but I do need to clean the filter now that I have clear water (after two rounds of cleaning the filter to get the water clear). Normally it's runs around 14psi when it's clean.

So from the sounds of it, I'll likely be able to keep the diverter 100% to the heater on high.

 

[1poolman1]

With the heat pump inline, on high speed the flow rate should be around 44 GPM and low speed 22 GPM with a clean filter. If the estimate is correct, filter pressure should be 19-20 PSI on high speed.

Without the heat pump, high speed flow rate is 48 GPM, low speed 24 GPM with high speed filter pressure 17-18 PSI. Let me know if that filter pressure is pretty close to what you are seeing now.

Hayward says that pump is capable of 91gpm (finally found it). With the configuration shown your figures are much closer to reality.
I used to use one of their SP1500 1hp above ground pumps as a vacuum-to-waste pump for very dirty pools. On an open line it probably did pump 75gpm or more. Put it on a filter system and you got maybe half that.

 

[Enrico_S]

Nice to see an above-ground pool with a proper equipment pad.
Many years ago Nature 2 offered a free item like yours if we went to their school to learn to use them. I went, got the mineral dispenser, installed it, went through three refills then cut it out of my system as I saw nothing different about my water. Much younger then and willing to experiment with stuff. Just a suggestion that you may not need it and it is just an added cost and restriction to flow.

Thank you. I was very new when I had my pool installed a few years ago, but I've learned a bunch in the last few years. My installer didn't really put too much thought into how he installed it, as he put in a lot of threaded fittings and glued in the pipe, without taking into account how I was going to unscrew both sides. So I've added a few unions/valves to make it easier to replumb my pool each spring and not lose as much water when I want to clean out my filter or pump basket.

The Nature 2 was included in the pool package, and I actually haven't changed the cartridge yet. This year will be the first time I do since it was new in 2020, so three seasons. I know they say to change it every year, but like you said, it's an added cost.

 

[Enrico_S]

Hayward says that pump is capable of 91gpm (finally found it). With the configuration shown your figures are much closer to reality.
I used to use one of their SP1500 1hp above ground pumps as a vacuum-to-waste pump for very dirty pools. On an open line it probably did pump 75gpm or more. Put it on a filter system and you got maybe half that.

I couldn't find that info anywhere?!? Where did you find it? I actually have a call into Hayward tech support, and I'm waiting for a call back.

 

[mas985]

Right now, on high, it's around 16psi, but I do need to clean the filter now that I have clear water (after two rounds of cleaning the filter to get the water clear). Normally it's runs around 14psi when it's clean.

So from the sounds of it, I'll likely be able to keep the diverter 100% to the heater on high.

What size is the eyeball/opening in the return? I had assume 3/4" but 1" makes the filter pressure closer to what you are seeing.

New numbers with 1" eyeball:

With heat pump, high: 51 GPM, low: 25 GPM
Without heat pump, high: 58 GPM, low: 29 GPM

 

[1poolman1]

I couldn't find that info anywhere?!? Where did you find it? I actually have a call into Hayward tech support, and I'm waiting for a call back.

I believe it was in a FAQ on Inyo Pools site. Have looked many places.

 

[mas985]

I believe your pump is a clone of the US Matrix SP15932S so it should have the same head curve.

Manufactures will often times quote the pump run out as the maximum flow rate but that is never reality plus the pump should never be run anywhere close to run out.

PowerFlo® Matrix High Efficiency | Pumps | Above Ground Pool Pumps - Hayward Pool Products

Hayward PowerFlo® Matrix high efficiency pumps are engineered to dependably adapt to the unique needs of a wide variety of above-ground pool setups.

www.hayward-pool.com

https://hayward-pool-assets.com/assets/documents/pools/pdf/literature/Hayward-PowerFlo-Matrix_eLITPFMHE21.pdf

 

[Enrico_S]

What size is the eyeball/opening in the return? I had assume 3/4" but 1" makes the filter pressure closer to what you are seeing.

New numbers with 1" eyeball:

With heat pump, high: 51 GPM, low: 25 GPM
Without heat pump, high: 58 GPM, low: 29 GPM

Pretty sure it's a 1" opening, since I had to use my thumb to plug it when I was adjusting the valve at the salt cell