Hello, new to pools. Engineering degree. Pool installed last summer already Upgraded to an intillifloV3 pump everything is good. circulating 30gpm at 25% speed 150watts. I installed a Raypak (Rheem) 140k BTU heat pump pool heater, with a bypass valve (jandy neverlube) and a Hayward check valve on the outflow side of the heater. The problem when I turn on the heater at the recommended 45gpm my pump jumps to 95% speed and 1500watts. 10x the power consumption. Pressure gauge on filter jumps from 15 to 30PSI. Heater works, tested for 5 hours and it was going up about 1degF/hour @60F ambient. My question is this kind of flow restriction and pump load common or expected. Is this a common Raypak problem? It’s an impressive heat exchanger, thing is a monster seems very well build….now I am just wondering if they are no good at the fluid side? The heat pump loop is 10 feet of pipe total, 6 elbows, 2 x 45 degrees, and a Hayward check valve. Any thoughts?
NEW Raypak Heat Pump Heater significant flow restriction?
- Thread starter hotpool2468
- Start date
What’s your heat pump model number?
I have the 8450TI-E-HC with intelliflo3 3hp.
I do not have a bypass, so I’m always running through the HP. New build for me and I plan to reconfigure the plumbing to allow a bypass. But, as it sits now, I can’t flow more than 55GPM at full pump speed. 2” main drain. 1.5” strainers. 1.5” returns.
I also get an alert about excessive pressure in the pump at that speed.
My gut tells me the HP significantly restricts flow but, without a bypass, I can’t test that theory yet.
- Jul 21, 2013
- 53,690
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Welcome to TFP.
Heat pumps have a more restrictive flow than gas heaters. None of the pool heat pumps are very good for flow efficiency.
Show us pics of your equipment pad.
Heat pumps have a more restrictive flow than gas heaters. None of the pool heat pumps are very good for flow efficiency.
Show us pics of your equipment pad.
Okay then I have the same unit. That matches about what I have on flow.. I don’t think I can hit 50gpm haven’t exactly tested 100%. I think adding that bypass will drop your electricity use by about 8x according to my case study. I find it interesting I can’t find anything anywhere to this conversation. Electric bill was rough and I ran the heater for only 5 hours. Looking into the manual it says a pressure drop of 9psi is to be expected with this unit. The same size Pentair only lists a 5psi pressure drop so significantly less restriction. It was really shocking. I am going to add an actuator to my bypass and try to figure out the automation and freeze protection. Thinking of setting to 90 degree action so either all through heater or both open. Close off flow through heater with manual control if I need to for service or something. Even with the bypass valve full open both sides I don’t think much water if any is getting through the heater core at lower speeds.
We have similar sized pools, I am 15k. I’m not running my 3hp intelliflo3 pump anywhere near that 45+ GPM ever.
My go to is 25% speed which is about 15GPM. I bump up to a setting of 30GPM for a few hours when adding any chemicals or cleaning with manual vac. I have not found a need to be above 30gpm. I am about 55% speed at 30GPM.
One of the experts can chime in… but I think I read on here and understood that much more than 50-60GPM was not a something my plumbing would appreciate. Too much flow for the pipe size (or however you say that, technical, ha!).
All that said, I still plan to plumb a manual bypass that will allow me to divert all, or some, water through the HP to see if that lessens resistance and improves my pumps efficiency. Let me know your results! I’m curious.
My go to is 25% speed which is about 15GPM. I bump up to a setting of 30GPM for a few hours when adding any chemicals or cleaning with manual vac. I have not found a need to be above 30gpm. I am about 55% speed at 30GPM.
One of the experts can chime in… but I think I read on here and understood that much more than 50-60GPM was not a something my plumbing would appreciate. Too much flow for the pipe size (or however you say that, technical, ha!).
All that said, I still plan to plumb a manual bypass that will allow me to divert all, or some, water through the HP to see if that lessens resistance and improves my pumps efficiency. Let me know your results! I’m curious.
Attachments
- Jan 7, 2012
- 1,525
- Pool Size
- 21000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
What's the minimum pump speed needed to close the flow/pressure switch in your HP? Slowly lower your pump RPM and see when the HP cuts off. Add ~100 RPM to that speed and that should give you a good reference point.
I normally have it at 25% speed. It puts out >20 gpm on bypass and ~8gpm through the heater. Not enough flow to run the salt cell even. The minimum flow for the heater operation is 30gpm according to manual 45gpm for maximum efficiency.
Attachments
- Jul 21, 2013
- 53,690
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
2" schedule 40 can take 280 PSI. You cannot get there with your pool pump. Don\'t worry about your plumbing. Crank up your pump as much as necessary and see what GPM flow you can get.
That said running 2" pipe more then 63 GPM in suction and 84 GPM in returns the friction increases and the pump needs to work harder to get diminishing increased flow.
Higher then minimum flow rates do not get heaters to heat better. Around 30-40 GPM seems to be the sweet spot for heater flow.
Is it possible my check valve on the output is contributing to my flow problems? Not enough psi to keep it open? At low speed the pressure gauge on my filter barely registers anything. With the pressure drop through the heater i suppose it doesn’t have enough pressure to adequately open the check valve.
Pump exact model number?
3 HP or 1.5HP?
www.pentair.com
3 HP or 1.5HP?
IntelliFlo3® VSF Pool Pump
The Intelliflo3 VSF pool pump includes auto regulating flow technology, energy savings, and superior performance for crystal clear water.
Pump P/N (Part Number or Item Number) from barcode sticker?
What is the Flow, Power, System Pressure and Filter Pressure at several speeds with the bypass open and the bypass closed?
online.flippingbook.com
What is the Flow, Power, System Pressure and Filter Pressure at several speeds with the bypass open and the bypass closed?
Sell Sheet | IntelliFlo3 VSF Pool Pump
Thanks for this.
I agree, just with my gut - no facts (until now), that I don’t have a need for north or 40GPM. However, if I can reduce restrictions and increase efficiency I’m all for it.
Your system curve with the heater is really bad at about y = 0.03669 X^2.
The heater is about H = 0.00924F^2.
So, the system without the heater would be about H = 0.02745F^2.
At 45 GPM without the heater, the system pressure would be about 24 psi.
With the heater, the system pressure will go to about 33 psi.
Curve A: H = 0.0167 x F2 (Curve 2.0)
Curve B: H = 0.050 x F2 (Curve 1.5)
Curve C: H = 0.0082 x F2 (Curve 2.5)
Where: H is the total system head in feet of water.
F is the flow rate in gallons per minute (gpm)
www.aquamagazine.com
www.wolframalpha.com
The heater is about H = 0.00924F^2.
So, the system without the heater would be about H = 0.02745F^2.
At 45 GPM without the heater, the system pressure would be about 24 psi.
With the heater, the system pressure will go to about 33 psi.
Curve A: H = 0.0167 x F2 (Curve 2.0)
Curve B: H = 0.050 x F2 (Curve 1.5)
Curve C: H = 0.0082 x F2 (Curve 2.5)
Where: H is the total system head in feet of water.
F is the flow rate in gallons per minute (gpm)
How to Read Pump & System Curves
If you find yourself somewhat mystified by pump curves and performance charts, or if you need to train someone about hydraulic efficiency, here’s a brief primer to get you started.
www.aquamagazine.com
y=0.03669X^2, y from 0 to 75 - Wolfram|Alpha
Wolfram|Alpha brings expert-level knowledge and capabilities to the broadest possible range of people—spanning all professions and education levels.
www.wolframalpha.com
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Put the flow at 45 gpm with the bypass open and with the bypass closed.
The System Pressure (Reading from pump) and the Filter Pressure should go up by the amount indicated.
What is the exact heat pump model number?
The 8450ti should increase the pressure by about 9.5 psi at 45 gpm, which is very high and ridiculous for a design.
In my opinion, this is a defective design and they need to get it below 3psi at 45 gpm.
The System Pressure (Reading from pump) and the Filter Pressure should go up by the amount indicated.
What is the exact heat pump model number?
The 8450ti should increase the pressure by about 9.5 psi at 45 gpm, which is very high and ridiculous for a design.
In my opinion, this is a defective design and they need to get it below 3psi at 45 gpm.
Here is the Ultratemp for comparison.
As you can see, heat pumps are horrible for pool systems in terms of flow efficiency.
In my opinion, they could easily cut the resistance in half with a better design.
As you can see, heat pumps are horrible for pool systems in terms of flow efficiency.
In my opinion, they could easily cut the resistance in half with a better design.
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Good to know I will just turn it down to 35gpm. It was shocking to amount of extra load on the pump going through the heater. Below are the pump screen shots for heater and bypass at 40gpm. Equates to an extra $5/day of electricity just on the pump side let alone the draw for the heat pump. I would go with the Pentair 140HC if I had to do it again. Poor fluid dynamics design on this thing. Unimpressed, seems very well built otherwise. Probably designed with single speed pumps in mind….this thing throws away all the savings for having a variable speed pump.
Attachments
Heat pump Model # R8450TI-E-HC and a Pentair IntelliFlo3 VSF Pump 3.0HP.
The first is H = 0.03375F^2.
The second is H = 0.0075F^2
That puts the heat pump at about H = 0.02625F^2.
The heater should be about H = 0.00924F^2.
The heater is about H = 0.017F^2 over what the book indicates.
The heater is about 2.84 times more restrictive than the book indicates.
The second is H = 0.0075F^2
That puts the heat pump at about H = 0.02625F^2.
The heater should be about H = 0.00924F^2.
The heater is about H = 0.017F^2 over what the book indicates.
The heater is about 2.84 times more restrictive than the book indicates.