Raypak 8450 (140,000 BTU) Real World Feedback vs solar cover or gas heater

Enzodast

Active member
Jul 22, 2020
36
Connecticut
Pool Size
33000
Surface
Vinyl
Chlorine
Liquid Chlorine
Hey everyone,

Been all over the forums reading a ton on gas vs heat pump. I could use some help from some of you who are MUCH more mathematically inclined than i am....

Pool Details: 40x20 double roman liner pool. approximately 34,000 gallons
Location: Connecticut
Sun/shade: FULL sun. No shade whatsoever over the pool.

I'm most likely definitely purchasing a rockys 5a reel and a 12mil cover to retain heat and also help build heat during the day.

I'm also contemplating adding a Raypak heat pump. When i built the pool last year i pre-wired the heat pump but did not plumb for a propane heater but if it's that beneficial to go with propane i will go through the effort of permitting and running a new line (really don't want to).

Can someone help me with the math calculation of the Raypak described above versus a gas heater or do i just stick with a solar cover this year and hope the solar cover does enough to allow us to swim in June and into September.

We are not trying to get the water to 85degrees....80 degrees is probably our ideal temp.

I also DO NOT want to run my pump for more than 12 hours per day, i prefer 8 to 10 hours. Which means at most the heat pump would be running only during that time frame. I'm okay with running it extra (12 hours) when really trying to add heat in may/june/september.

In June in CT the average HIGH temp is 78 degrees and night temp is 59. (pool temps with no heating are probably close to 69/70 even during June on average. I want to raise it about 10 degrees to 78 or 79 degrees in june if possible. Can a solar cover alone do this? Solar Cover plus heat pump? I'm lost at this point and could use some help.

Thank you!
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
24,801
Northern NJ
Pool Size
35000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
Raypak has a Gas Pool Heater Sizer. It tells you the Temperature Rise/Hr and Natural Gas and Propane costs to heat a pool in your local area to selected temperature by month. Adjust the natural gas cost and propane cost in the lower left to your local gas prices for accurate costs.

Pentair has a Heat Pump Calculator to determine the appropriate size Heat Pump for your location. Pentair seems to do honest calculations based on the physics and efficiencies of each type of pump and energy source.

Raypak also has a Heat Pump Heater Sizing App.

To get the most accurate cost comparison you should change the default electric kwh, natural gas price, and propane price to actual prices in your area.
 

Enzodast

Active member
Jul 22, 2020
36
Connecticut
Pool Size
33000
Surface
Vinyl
Chlorine
Liquid Chlorine
Raypak has a Gas Pool Heater Sizer. It tells you the Temperature Rise/Hr and Natural Gas and Propane costs to heat a pool in your local area to selected temperature by month. Adjust the natural gas cost and propane cost in the lower left to your local gas prices for accurate costs.

Pentair has a Heat Pump Calculator to determine the appropriate size Heat Pump for your location. Pentair seems to do honest calculations based on the physics and efficiencies of each type of pump and energy source.

Raypak also has a Heat Pump Heater Sizing App.

To get the most accurate cost comparison you should change the default electric kwh, natural gas price, and propane price to actual prices in your area.
This is fantastic, thank you for these links! Math on the propane shows almost 6k in heating expense for May to September to maintain 82 degrees. Even if i only heated in june and september its nearly 3k in propane costs.

Then with the heat pump to raise the pool 10 degrees i need an average run time of 23 hours...so if i only run the pump 12 hours at a time in may and june, at BEST i'm going to raise the temperature maybe 5 degrees or so throughout the course of the week, coupled with the solar cover... Just hard to figure out if the 5 approximate degrees will make all that much of a difference to truly extend the season.

The more i talk this out loud i may need to just do the solar cover this year, see what kind of experience i have with it, are there heat gains at all, and then re-assess next year if i need to bite the bullet on a true heating system.
 

coolviper777

Member
Jul 2, 2020
9
Pittsburgh, PA
I am in the same boat as you are. I'm in Pittsburgh, PA, and have considered this same HP. I have ruled out Gas heat, since it would be expensive to run a gas line over 100 feet, and the heating cost from the Raypak calculator is about $700 more a season. So, HP it is, in combination with a solar cover.

I'm curious about your condition to only run the HP only for 8 to 10 hours? That's actually the point of the HP, it's more efficient than gas, but you have to run it for about twice as long. The cost isn't that much to run 16 hours from the Raypak calculator, around $100 per month.

The solar cover will certainly help all by itself, but its best used in combination with a HP or Gas heater, since my experience with it is that won't significantly extend your season. It will help with night time heat loss. And if clear, it will help with heat gain from the sun, especially during June through August. But you have to keep it on when you aren't using it. And it will work best June through August, as the Sun gives the most heat during those months. That's what I've seen in Pittsburgh, PA, with our solar cover.
 

coolviper777

Member
Jul 2, 2020
9
Pittsburgh, PA
I have my Raypak 8450 on order, expecting it by the end of the first week of May, and will hopefully have it up and running by the 2nd week in May. I will give an update on how it's working for me here in Pittsburgh. My pool is the same size and approx same gallons as you have (20x40 @36,000 gallons, wooden wall pool with vinyl liner). I will also be replacing my skimmer and return lines and upgrading them from 1.5" to 2", since they are flex lines instead of sched 40 PVC. Maybe add an additional return for a pressure side auto cleaner. Got a new 12 mill blue solar cover as well.

After the initial pool heat up, which is 2 to 3 days of near constant running, I will plan to run the heat pump during the day during May and probably early June (maybe 10am to 6pm). As I understand it, the heat pump is most efficient then, and will get closer to it's 140K BTU rating, versus closer to 80K BTU if the temp is say 55F at night. Combined with the solar cover minimizing heat lose and giving a bit of a boost from the sun, hope to be swimming with the family on nice days by 3rd week of May, and extend the comfortable swim season to end of September.

This will be our 2nd summer at this house with a pool. Last year, we only had a solid blue/blue solar cover, which we did use, and it did help. We moved into this house beginning of July, so the pool was relatively warm, prob around 82. It probably peaked around 86 end of July and beginning of August. It was a nice temp until we left for about 10 days near the end of August. We came back and the pool had lost about a foot of water due to an unnoticed leak, which I fixed. However, putting in cold tap water to raise the level brought the pool down to probably 74 water temp, which wasn't too pleasant for the the family, though I didn't mind too much. By 2nd week in September, pool water was probably 70F, and the solar heating wasn't enough to heat it much anymore. I think I measured 68F water by 3rd week of September, which wasn't terrible on a hot day, but it did hurt the head a bit if you went underwater. Of course, I was the only one swimming.

Hoping this year to keep the pool around 80F during September and if weather cooperates, maybe even use it a bit in early October. I actually didn't close it/winterize it/drain below skimmer until early November, since the water temp stayed above 60 until around that time and the weather here doesn't get cold enough until December to really start freezing much, with January/February being the coldest winter months.

Regarding propane/natural gas heaters: I am also having a gas line run for the pool area and the addition we will building. So, I may also put in a gas unit next year, to help with getting the pool open early, and for late season use in October for any nice weekend that come up. We will see how the heat pump works for me here.

Propane heater may be useful to you for supplemental heating. It would be very expensive as your only heat source though. Another thing to consider is that you can install 2 heat pumps, and get double the heating effect. Even that would probably be cheaper in the long run that running propane. Natural gas is different as it's much cheaper at this point.