how low can you go (water temp)?

[engrav]

So pool is not closed in winter. Is 25k inground. How low can I let the water temp go before turning on the heater?

 

[ajw22]

The Physics of Freezing and Freeze Protection

 

[engrav]

Interesting. Thanks. My pipes and stuff are underground or indoors so I think not a problem. I was more thinking of the water itself in the pool which this evening was 33°.

 

[ajw22]

You don’t run the heater in freezing temperatures. Just run the pump. Flowing water has a lower freezing temperature . Modern pumps and automation have freeze protection circuits that run the pump when temperature hits 32F.

 

[mas985]

Interesting. Thanks. My pipes and stuff are underground or indoors so I think not a problem. I was more thinking of the water itself in the pool which this evening was 33°.

The biggest risk is probably the skimmers. Once you see ice start forming on the water surface, you probably want to keep the pump running full time or close the pool.

 

[engrav]

Interesting. Getting more interesting.
I checked the ComPool manual, says freeze protection starts if air temp hits 35.

So I checked the ComPool Easy Touch. At the moment, ComPool thinks air temp is 56 when outside it is 39. I suppose because the ComPool is inside the mechanical room and would appear the air thermometer is inside the ComPool.

If this is true, ComPool will never detect 35F so ComPool freeze protect will never activate.

Am running the pump 8hrs/ day at present as we have at this point very little tree debris.
Lowest temp setting on the ComPool is 40.

What is wrong with setting Heater to heat to 40? If it is 40, heater does not come on so no $$ wasted. If below 40, heater heats it up a bit.

 

[Geebot]

Interesting. Getting more interesting.
I checked the ComPool manual, says freeze protection starts if air temp hits 35.

So I checked the ComPool Easy Touch. At the moment, ComPool thinks air temp is 56 when outside it is 39. I suppose because the ComPool is inside the mechanical room and would appear the air thermometer is inside the ComPool.

If this is true, ComPool will never detect 35F so ComPool freeze protect will never activate.

Am running the pump 8hrs/ day at present as we have at this point very little tree debris.
Lowest temp setting on the ComPool is 40.

What is wrong with setting Heater to heat to 40? If it is 40, heater does not come on so no $$ wasted. If below 40, heater heats it up a bit.

From what I've read, there are serious condensation issues that arise when running a heater outdoors in near-freezing temps.

EDIT: Just found this in Raypak's manual:

CAUTION: Do not use the heater to maintain water temperatures just above freezing or for freeze protection. When heater is used during freezing weather, care must be taken to avoid freeze-ups. Continuous pump operation is a must. Additional protection may be required. The heater is not warranted against freeze-ups. COLD CLIMATE: Prolonged operation with water temperatures below 50°F is not recommended. When starting the heater with water temperatures below 50°F, operate the heater continuously until higher temperatures are reached. Operating the heater for prolonged periods with pool water below 50°F can seriously damage the heater, and is not covered by the warranty

 

[engrav]

Hi
Thanks
Heater here is a Burnham oil boiler connected to a Maxi-Flo heat exchanger both located indoors.
Would this system also be bothered by cold water? It seems to work Ok.
Will check with my heater guys.
thanks

 

[Thurston]

Why don't you close it? Seems like a lot of energy spent to keep it open. Just curious

 

[Geebot]

If the heaters are indoors and not subjected to freezing temperatures then you should not have issues with condensation. I don't feel qualified to give you the green light, but it's a much different scenario than heaters that are located outdoors (like mine in freezing Chicago).

 

[borjis]

if you're like me and keep your pool at open water levels year round, but do drain the filter, heater & pump, make sure
to put an empty plastic milk jug (filled with some rocks to hold it down) in the skimmer. This will prevent the ice from
expanding into and cracking your skimmer. Instead the jug will take that force.

2 winter's ago we had a brutal arctic blast. pool was frozen solid for 2 weeks with about 5 inches thick ice and my skimmer had zero damage
thanks to the jug.

 

[engrav]

close the pool? gonna explore that
When we bought we just assumed the methods of the previous which was chlorine tabs and never close and no cover.

Over time tabs morphed into the TFP bleach method but we continued to never close. Did buy a cover for Fall when the surrounding forest sheds.

Is true winter maintenance is "easy" since chems never change, chlorine lasts forever. And very little to skim/vac.
But is true 8hrs pump / day is $50/month. And say closed 7 mo would be $350 electricity.

Of course, I don't know how to close. But will read up and see if the effort would be worth it.

I assume TFP has page(s) on how to close.

thanks

 

[engrav]

I read
Trouble Free Pool

of course have never done it but

seems like lotsa work and
expense for closing chemicals
expense for electricity to refill pool from the well
expense for chemicals to rebalance

so maybe winter pump costs and couple jugs chlorine not so bad

 

[Rocket J Squirrel]

At the moment, ComPool thinks air temp is 56 when outside it is 39. I suppose because the ComPool is inside the mechanical room and would appear the air thermometer is inside the ComPool.

If this is true, ComPool will never detect 35F so ComPool freeze protect will never activate.

The air temperature sensor should be outside in open air. I suggest opening the enclosure to get a look at the sensor and the length of its cable. It might have enough coiled cable to relocate the sensor. And if it doesn’t, you can obtain one that has a long enough cable to properly relocate.

 

[engrav]

The air temperature sensor should be outside in open air. I suggest opening the enclosure to get a look at the sensor and the length of its cable. It might have enough coiled cable to relocate the sensor. And if it doesn’t, you can obtain one that has a long enough cable to properly relocate.

I think you are correct. What good is temp measured inside the building? I will check it out tomorrow.

But we have lotsa temps in Jan Feb between say 25 and 35 which would be lotsa pump hour electricity.

Is complex; which is cheaper
12hrs pump / day for 60 days with no heat ( would be about $70 / 60 days) or
8hrs pump / day for 60 days ( about $47/ 60 days) with oil burner to heat to 40

I have no idea how much oil the boiler burns in one hour and if water is 40; boiler does not fire; so calc of oil cost is kinda tough

will ask heating guys re: oil burned per hour

thanks

 

[mas985]

I'm not entirely sure you have anything to worry about freezing except for the pool surface. Normally, the most vulnerable area is the exposed plumbing of the pad equipment. Since this is shielded, there is really no chance of that freezing.

The pool itself will freeze and there are suggestions on how to protect the skimmers so there doesn't seem to be much risk there either.

The only other area of a potential problem is the plumbing underground. From frost depth maps of your area, I don't think you have anything to worry about.

So what is the concern?

 

[engrav]

So what is the concern?

Now that is another good question. Maybe the best yet.

How did this come to pass?
I saw pool temp at 33 and got jittery.

Was likely 33 other years but I did not notice so did not get jittery and nothing bad happened.

Is true pipes are underground or inside the mechanical room.
Is true that closing would be fair amount of work / $$.
Is true that relocating the thermometer and running the pump if air temp < 35 would be fair amount of $$.
Is true that lowest ComPool heat setting is 40, well above the freeze trigger of 35.
Heat guys have responded and boiler likely take ¾ gal / hr. Say pump runs 8hr/day and heater 4hr/day to keep it 40. Say this is an issue 60 days Jan and Feb. 4hr/day * ¾ gal/hr * 60 days * $2.50/gal is $450. Now that is not chump change.
Is true that when heating 33 degree water the temp of water returning to the boiler from the exchanger can be 95 degrees and heater guys responded boilers do not like return water that cold. Could condense whatever that means.

So I am thinking
1) chill out so to speak
2) go back to 8hr/day pump
3) and if there is no surface skim ice; all is well
4) and if there is some surface skim ice , increase pump time and the eyeballs will ruffle the surface and dispose of the ice
5) and if there is some skimmer skim ice, increase pump time and the vigorous flow over the weir doors will solve it
6) and no additional cost / effort unless I see a little ice somewhere

In fact went out and turned the heater off
Stopped the oil dollars from passing up the chimney
And reduced our CO2 production

Thanks

 

[mas985]

Sounds like a good plan!

But I might add that 8 hrs per day without any ice is probably overkill. 4 hrs per day well more than you need as long as the chlorinator can keep up.

 

[engrav]

Sounds like a good plan!
4 hrs per day well more than you need as long as the chlorinator can keep up.

Chlorinator keep up? Chlorinator is me. And half jug 10% lasts two weeks in Feb.
4 hr? wow that would save even more. Should it be 4 hrs in one chunk or 4 one hr chunks?

 

[Rocket J Squirrel]

Is true that relocating the thermometer and running the pump if air temp < 35 would be fair amount of $$.

Yeah, the problem there is that you have a newish 1-speed pump. A variable speed pump runs at very low RPM just to keep the water moving.