can I use a swimming pool ASHP for my UFH?

cretanrunner

Does anyone know whether there is any significant technical difference between an air source heat pump for a swimming pool and an ASHP for UFH? The pool ones seem a lot cheaper so I guess there must be some reason for that. The question is whether it is something that would stop me using one for UFH? I can't see any obvious difference, maybe the pool ones need a higher flow rate?

Any comments appreciated.

richardc1983

The pool ones will be of much smaller capacity look at at the output in BTU of the system then compare that to the BTU you require to heat your house.

cretanrunner

Well, that's not actually the case. There are many pool pumps that are way more powerful than what I will need for the house. Thinking around 12kW. Sorry, we don't do BTU's in Greece!

I was wondering whether there might be differences in component quality, in the fact that they may be designed for much higher ambient temperatures, and in the fact that they seem to require much higher water flow rates?

[Deleted User]

Why not download the spec sheet and compare with the spec sheet of say a similarly sized Daikin Altherma/Ecodan etc. Use a highlighter pen to note significant differences

cretanrunner

Good idea, if only I felt confident about interpreting the specs! I've already done that up to a point, which is how I came up with the few points of difference mentioned earlier.

What I need is a specialist who can say one way or another if it will work, and why. Or someone who has done it.

One of my worries is that I've been told the components are inferior in a swimming pool heat pump. But I can't see why that should be the case. I doubt the thing has to work any less hard.

[Deleted User]

cretanrunner wrote: »

Good idea, if only I felt confident about interpreting the specs! I've already done that up to a point, which is how I came up with the few points of difference mentioned earlier.

What I need is a specialist who can say one way or another if it will work, and why. Or someone who has done it.

One of my worries is that I've been told the components are inferior in a swimming pool heat pump. But I can't see why that should be the case. I doubt the thing has to work any less hard.

Sorry, that's all I could think of... All an air to water ASHP does is heat water whether rads or an exchanger for pool so perhaps a swimming pool pump is designed for pretty much constant running so harder wearing...

There are others on this site with a great knowledge so hopefully they will reply.

Cheers

cretanrunner

Thanks Jeepjunkie, I also feel a pool heat pump is likely to be just as hard wearing, and I can't get away from a sneaking suspicion that ASHP for domestic heating cost so much more due to the brand names involved and the usual premiums for anything that can be labelled "eco" or "green". Or am I just being cynical?

Hopefully someone in the know will respond, or are there too many with vested interests?

lovesgshp

From a very experienced engineer on the subject today:
C
R
A
Z
Y

Cardew

Swimming pool heaters are designed to heat huge amounts of water a tiny amount.

A typical flow rate is 4,000 litres an hour - over a litre a second. If the flow rate is reduced, typically in a swimming pool by a dirty filter the Heat pump will overheat and shut down.

You would need a fire engine outside your house to to get a pump big enough to that push that amount of water through domestic pipes and a union bursting would be interesting!!

I suppose instead of narrow or micro bore pipes you could install 3 inch piping!

cretanrunner

Cardew, thanks for that. I've been trying for a long time, on several different forums, to get a reasoned answer to my question, rather than people just telling me it won't work and I'm bonkers. Nothing more certain to make me pursue it even more!!

I had already identified the flow rate as an issue, as mentioned in my earlier posts. And I agree, that is probably going to kill the idea. But what if you had a 1500L cylinder, and the heat pump supplied that, as a closed circuit, using large bore pipes. The supply to the UFH would be via heat exchanger (coil) at normal flow rates.

Worth investigating?

Cardew

I was just looking at the Calorex technical spec for their Y range for indoor swimming pools. They are more expensive, but operate down to -15C.

However their flow rate is 2 litres per second, so the water in your 1,500l tank will be changed every minute!!! With that amount of water flowing through your house, with inevitable air in the pipe, it will sound like Niagra Falls.

Don't forget you will need to fit a(noisy) swimming pool pump which will need to self prime? Noise of heat pump?

You will have to check manufacturers spec, but about 30C is maximum water temp I believe.

What about hot water for baths showers etc?