Portable Heat pump

sk240

Hi,

Has anyone any experience with a mobile heat pump such as

http://www.4air.co.uk/eco12p-13000-btu-portable-air-conditioning-p-996077224.html

I cant really see how it works, anyone any idea? it looks good in theory

sk240

another link
http://www.ecoair.org/library/Air-Conditioning/Portable-Air-Conditioning/Brochure-Portable-Heat-Pump.pdf

Cardew

There are loads of Aircon units that have a dual heating role and ASHPs that have a dual aircon role)

This one only heats when the ambient temperature is above 7C.

If you want a air to air ASHP(Air Source Heat Pump) then you will pay more.

sk240

Does it work by sucking air back in fom outside? and thats why it will only work down to 7 degrees?

Cardew

Yes a heat pump is the 'reverse' of air-conditioning, or better described as a fridge in reverse.

However a purpose built heat pump of this type - known as an Air to Air ASHP(Air Source Heat Pump) - is capable of operating and producing warm air when the outside temperature can be down to -15C or so.

Most of the cheaper appliances of this type are Aircon units with a limited heat pump function, or Heat pumps with a limited aircon function.

grahamc2003

sk240 wrote: »

Hi,

Has anyone any experience with a mobile heat pump such as

http://www.4air.co.uk/eco12p-13000-btu-portable-air-conditioning-p-996077224.html

I cant really see how it works, anyone any idea? it looks good in theory

It's certainly not clear to me how this equipment works, even though I know the thermodynamics of heatpumps/fridges/aircon/dehumidifires, which all work on the same principal.

There only appear to be one vent pipe and I would have expected 3 or 4 judging by the functionality it claims. You need an air input to each of the 2 heat exchangers, and an air output from each one too, and, depending on what function you wanted, two or three of then would have to vented outside for the thing to work efficiently. One concernign thing is that it said something like the heat is absorbed from the air around the unit (meaning no vent pipe on that air input) - and I can't think that would be much use if the unit were used for heating (i.e. you're extracting the heat from the room you want to heat, which seems odd, except when in cooling mode).

It claims a cop of 3ish for heating - but for that you'd need outside air over the evaporator, and the cooled air after the evaporator would also need to be vented outside (so two vents for heating). If, as I supect, internal air is used over the evaporator and then exhausted outside, then the cop may well be 3ish, according to the formula to calculate it, but it would in effect be an exhaust heatpump, meaning much of the heat is taken from the internal room air itself (i.e. the net heating would be less than a cop of 3 suggests).

Although I'd love a varsatile heating/coling unit as the blurb suggests, my impression at the moment is that the performance wouldn't be as good as the numbers suggest. I'd like to get my hands on the technical manuals to see what they say.

btw, I've just bought an ecoair dessicant dehumidifier, which I think is really good.