New owner - cutting heat and cost in winter

[wivsi]

Hi, we have just bought a property with a pool, in the UK. It's an indoor pool, approx 10,000 gallons (according to the guy who built it many years ago). The pool has a gas boiler, which heats the pool itself and also the air, via a dehumidifier.

I'm struggling a little with understanding what I can get away with for winter.

I've turned pool heat off, but according to the thermostat the pool is still at about 19c. I am therefore keeping the pool hall temp at around 21c. The pool has a fairly heavy duty cover on it. There is little condensation in the room (although two patches appear daily on the rubber ceiling which I assume is where there are cold spots in the roof space - I can't access the roof space to see whats there).

I am wondering if I should be turned down the room heat further, seeing as there is a cover on. I'm also confused that my cheap Amazon humidistats show 70% RH, I've got the dehumidifier set to 55%, and if I mess with dehumidifier controls it only kicks in if I set RH at 25% - so dehumidifier seems to think room humidity is that low.

I really want to pretty much shut things off for winter, without going as far as full winterisation as we may occasionally want to use the pool.

I think my question is... what can I get away with? If the pool refuses to go below 19c odd, can I still turn room temp down below this or is it going to massacre the humidity levels?

Any advice etc welcome. I've googled a lot. Pool company are rather relaxed about it all...

Thanks in advance for any ideas or pointers!

[Teapot1]

Pool cover heavy duty? Insulated cover?
Having purchased a few humidistats I have seen quite some errors so unless you can check it against another one its anyones guess.
If the water is cooler than the air you shouldn't get much humidity showing as its due to the dew point. Cold dry air vs warm wet air. Your dehumidifier is a bit worrying if it wont kick in around 5% of the RH.
You wont need full winterisation on an indoor pool just run the pump for a while to keep water filtered and circulating.

[wivsi]

Hi - thanks for the thoughts. Yeah an insulated cover from what I can tell. It's maybe 10mm thick, so I assume there's some insulation in there.

Humidistats - I bought 2, in a pack. They are both showing similar.

I've just got a water thermometer and it shows about 22C in the pool! Without heating on for a week. Room temp is currently about 18C, having turned it down today to see what the effect it. I have had the heating on above pool temp and I guess the warm air could be heating the pool....

I've got the pump set to 4 hours per day which is enough to fully circulate once per day. Not too worried about the pump. I think my biggest concern is ending up running the dehumidifier for hours every day to try to catch up. Or, failing to run it! We seem to be getting through a lot of energy, but also I'm not sure how much of that relates to the dehumidifier - whole place is new to us so plenty to work out.

[wivsi]

I've just put one of the humidistats in my house and it's showing 68% in here as well. Possibly crap humidistats...

[Teapot1]

Good news is its sounds like you have a pretty good pool for holding the heat and a great cover too. If the cover is a reasonable fit to the perimeter of the pool it will be doing a great job of keeping the humidity down. If you can put your pool thermometer on a pole and take a reading deeper youll see if it really is warm as water stratifies so things look better at the surface. What size pump have you got? Fitting a pump speed controller will allow you to wind the pump down and that can make big savings. What does your pressure gauge read when the pump is on?

[wivsi]

Thanks... stranger and stranger, I just checked the temp when holding a thermometer under water and its showing 20 degrees plus. So room temp is now about 15 degrees, pool temp is about 20, and there is basically no condensation in the room that I can see despite a humidistat showing 80% - compared to when it was warmer, and there was condensation on the ceiling and windows.

I'm even more confused!

[wivsi]

sorry forgot the other Qs. Pressure gauge is broken, so not too much help. Pump is 750w I think.

[Teapot1]

I am guessing with the air temp at 15 any condensation is on the underside of your cover not in the room. Dont forget relative humidity is relative to temperature not absolute humidity. Amazing that your water temperature is holding that well deserves further monitoring. .75hp would be about right for that size of pool usually about 750-800w when running, worth getting a new gauge though. By way of example my pool is a similar setup but re engineered for low energy, on filtration I use 65w.

[Phil.c]

I have an indoor pool with an enclosure just like a conservatory, poly carbonate roof and glazing on three walls, in the winter I switch the pool and room heatiing off, I just have filtration on at 1200rpm for about ten hours a day. The pool temperature is around 10c. The windows do get condensation but it usually goes around mid-day. One of the walls is the house pine-end which doesn't have condensation on it at all.

Pool-2-x.jpg (486.35 KiB) Viewed 298 times

[wivsi]

Phil, sorry, slow response by me… but thanks, that is useful to know! We seem to have got the water temp down now so condensation is not so much of a problem. Will try your approach!

[Phil.c]

Sorry also for the late reply, been away in the sun

Interesting to read you have a de-humidifier that heats your pool, I have two floor heaters, one each end, they look like the old type electric storage heaters, about 5' L x 2.5' H x 10" W, there's a long cylindrical fan at the bottom that blows hot air through a vent at the top and with three fan speeds, gets the area hot in a few minutes and run via the pool heater which is oil.