OV9

I bought a small pool heat pump yesterday, set it up today and it seems to be working. Something I'd not realised, and can't find much discussion of, and which is fairly obvious once you think about it, is that in addition to warm water it also produces cool air. If it's taking heat out of the air to put into the water, something else must be getting colder. There's a decent flow of air going through and right now the output is ~10 degrees below ambient. It would be useful to duct it into the house somehow but it's too far away. Plumb it through a cool box or something ? It's not as cold as a fridge. It seems a waste to dump that useful cold back into the atmosphere !

Couple of radiators, couple of hoses, an electric waterpump and a fan for the cooler inside the house.

Although and decent runs of pipe work would need properly insulating otherwise they’d be warm before the cool coolant could reach your internal radiator.

I had the same thought last summer when our pool heat pump was exhausting nice chilled air which was being wasted. The heat pump was firstly next to the back wall of our kitchen which wouldn’t have benefited from being cooled.

The delta across any heat exchanger by the time you’ve added hoses, connections and the heat exchanger itself would be pointless.

That’s would be a nice thing to have if you could duct it directly into the house. It may be worth trying that if you can get very cheap ducting.

As it’s such a small volume then any output would be tiny after all the inefficiencies you’ll be adding.

Dave!

Simply purchase an old hot air balloon canopy : collect all the cool air whilst your pump is running, and then trot back to the house to pour it in at a juncture that suits you.

Cold air ballooning. Simples.

Surely you just need a bigger fan! When we were staying in New York the apartment came with a 1m diameter fan. That made for very effective cool winds

I think Dave has it right. If you have a heat pump or air conditioner (basically the same, but pumping heat in opposite directions) your waste output is to effectively an infinite reservoir. If you try to use that output then you’re actually trying to create a heat exchanger.

If the pump is pulling through ambient air to try and warm up its heat exchanger then sticking something behind that to be cooled by the now cooled air which is otherwise just going out into the atmosphere shouldn’t reduce the efficiency of the pump noticably as long as you weren’t causing too much of a restriction behind it.

I very much doubt any cooling you could get out would be worth it, maybe more useful just ducting it to blow over some cans of beer or something

mik wrote: Sun Jun 22, 2025 3:06 pm Simply purchase an old hot air balloon canopy : collect all the cool air whilst your pump is running, and then trot back to the house to pour it in at a juncture that suits you.

Cold air ballooning. Simples.

Even simpler, there's a big useless hole full of warm water already nearby. Empty it out and fill with the nice cold air then bring the furniture out of the house to enjoy it.

I really wanted to put a heat pump in our conservatory, as you can imagine it gets terribly hot in there in winter and it's only a short distance across the patio from that to where I erect the pool. So I could be cooling the house and heating the pool at the same time. Perfect heat-pumponomics. Will see how the next few weeks pans out, but I figured that pricing wise it'd be better to pick one up in winter when demand is low, right? Cheaper that way.

You could build a shed next to it, duct the cool air into the shed and have your shed as a cold store for cheese.

Marv nailed it. In hindsight it was so obvious.