New Gas Heater Selection

[robneyandrews]

Hello everyone,

Live in central Indiana (you are welcome for all of the high fructose corn syrup, btw).

Wife and I have 16 x 32 ft pool with one end 8 ft deep and other 3 ft deep.

We only use the gas heater 2x-3x per year. once in mid May to get water to 84ish - then maybe a time or two afterwards to top up temps if it's been especially rainy or cool out. We keep a solar cover on it at night and usually during the day.

Our 30 year old Haward 200,000 BTU Gas Heater no longer works. Looking to replace it this spring.

My basic question is - since I only use the heater a few times a year and don't really care if it takes 2 days to bring up the temperature - would it be OK to downsize to a cheaper and smaller Heater - say 150,000 BTU. Or would a 150,000 BTU heater not be able to get the job done?

Again, it if takes longer to heat the water - I can plan around that. Our kids have grown up and left - we're both pretty good at looking ahead for several days with plans.

Thoughts?

Many thanks

Rob

 

[ajw22]

Welcome to TFP.

The only savings you get is the initial purchase cost difference. If time to heat makes no difference then go for a smaller heater.

 

[PoolGate]

When I started reading your post I was thinking you needed a larger heater. Like a 400k model. There usually isn't much difference in price between different BTU gas heaters of the same brand. No real operational cost savings since the larger ones heat faster but use more BTUs. I would stay with the size you have since the gas line was sized for that.

 

[1poolman1]

Hello everyone,

Live in central Indiana (you are welcome for all of the high fructose corn syrup, btw).

Wife and I have 16 x 32 ft pool with one end 8 ft deep and other 3 ft deep.

We only use the gas heater 2x-3x per year. once in mid May to get water to 84ish - then maybe a time or two afterwards to top up temps if it's been especially rainy or cool out. We keep a solar cover on it at night and usually during the day.

Our 30 year old Haward 200,000 BTU Gas Heater no longer works. Looking to replace it this spring.

My basic question is - since I only use the heater a few times a year and don't really care if it takes 2 days to bring up the temperature - would it be OK to downsize to a cheaper and smaller Heater - say 150,000 BTU. Or would a 150,000 BTU heater not be able to get the job done?

Again, it if takes longer to heat the water - I can plan around that. Our kids have grown up and left - we're both pretty good at looking ahead for several days with plans.

Thoughts?

Many thanks

Rob

Your old heater would raise your pool temp .95 degrees/hour (when new). The 150K unit will raise it .69 degrees/hour. Won't cost more or less in energy as long as the cover is in place and take about 25% longer to get to your desired temp.

 

[robneyandrews]

Wow. Thank you everybody. Way better answers than I had hoped for. Thanks very much

 

[PoolGate]

Your old heater would raise your pool temp .95 degrees/hour (when new). The 150K unit will raise it .69 degrees/hour. Won't cost more or less in energy as long as the cover is in place and take about 25% longer to get to your desired temp.

Heat pumps are "variable" cost. The colder it gets, the less heat they put out so must run longer to deliver the same amount of heat. Low humidity also negatively affects heat pump operation. Gas heat does not have this problem. But BTUs are BTUs so the more you can put into the water, the better. Heat pumps, in an ideal world, working at an ideal temperature, working at an ideal humidity, are financially more efficient at delivering heat than gas. If you could match the amount of BTUs being delivered by each with ideal conditions, the heat pump should be cheaper to run. Of course 400k BTUs is what you get with gas whereas the largest heat pumps are around 150k BTUs.

 

[robneyandrews]

Hello again pool friends,

I installed our new Raypak 156A (150,000 BTU) this weekend. Only two trips to the hardware store (granted, on the 2nd trip I bought extra of any pipe or fitting that I thought I might need - so there will be a 3rd trip now to return the unused bits).

It installed pretty easily. Black pipe connections for the gas, and two water connections. I connected the gas line first, which allowed me to move the heater into the best location for the black pipe alignment. The water connection from the filter is a 1.5 inch spa hose - so tons of flexibility for placement. Right now I have it plugged into an outlet, but later this summer I plan to hardwire it into the electrical that powers the pump.

After waiting for my PVC connections to cure and dry, I switched it on and it worked perfectly. Nice warm water coming from the pool return ports.

Plan to have three grandkids over this weekend - so will start heating it up on Thursday.

Hope this lasts as long as my Hayward CZ2001 model - which made it approximately 30 years (I owned it for 24 of those years).

Thanks again for everyone's help. Your expertise was Much Appreciated.

Rob

 

[robneyandrews]

Update.

Maybe it's the slightly smaller heater (went from 200,000 BTU unit to 150,000 BTU unit), or maybe the internal design changed from 1995 to 2023, or perhaps changes to help with heat exchange efficiency, but my water output back to the pool ports is definitely lower.

Same pump, same filter, new heater. Assume that new heater is more restrictive than old heater.

When I put my hand in front of the water return - there is less water flowing into the pool.

3 reasons that I would care (that I can think of):
1. Is the pump working harder and therefor affecting its life span?
2. My solar cover is getting less water flow under it - thus affecting how much heat it transfers into the water for free.
3. When solar cover is off, there's less flow to sweep floating leaves into skimmer basket.

Since I only use the heater occasionally, wondering if I should build in a bypass circuit so that the water would not flow through the heater unnecessarily.

Has anyone else noticed something like this after installing a new heater?
Will my pump life be affected?
Would my bypass idea improve the situation?

Thanks for any help.

It's been hitting 90's in central Indiana last few days. Enjoying the pool after work.

Rob

 

[PoolStored]

Update.

3 reasons that I would care (that I can think of):
1. Is the pump working harder and therefor affecting its life span?

No appreciably. Should be fine.

2. My solar cover is getting less water flow under it - thus affecting how much heat it transfers into the water for free.

Nope. 75% of the heat loss is evaporation. Solar cover solves that.

3. When solar cover is off, there's less flow to sweep floating leaves into skimmer basket.

Most of the flow is from wind...should be a big impact.

Since I only use the heater occasionally, wondering if I should build in a bypass circuit so that the water would not flow through the heater unnecessarily.

Yes, that is the purpose of the bypass. Heater should be bypassed when not heating...

Heater Bypass - Further Reading

www.troublefreepool.com

Has anyone else noticed something like this after installing a new heater?
Will my pump life be affected?
Would my bypass idea improve the situation?

Thanks for any help.

It's been hitting 90's in central Indiana last few days. Enjoying the pool after work.

Rob

When was the last time you cleaned/backwashed your filter.