Air to Air Heat Pump for a Conservatory

smartn

I'd be really greatful to hear peoples experiences of air to air heat pumps in a conservatory. We are looking at buying a conservatory which will be 4m * 3.7m and fitted with pilkington K activ glass and argon filled windows etc but I want the conservatory to be useable in the winter and cool enough in the summer. It will have one brick wall to at least shoulder height and dwarf walls elsewhere. It's North facing.

Cardew

In my opinion that is by far and away the best application for an air to air heat pump.

These are widely used in the USA in trailers and the cheaper motel type buildings, shops etc. Cheap and well proven technology.

Noise for neighbours can be a problem.

smartn

Any ideas as to how long it would take to heat/cool? Bit of a how long is a piece of string question but I wouldn't want to have to put it on 8 hours before needed for instance... I forgot to mention I have Solar PV as well so in the summer a lot of the electric would be free.

grahamc2003

smartn wrote: »

Any ideas as to how long it would take to heat/cool? Bit of a how long is a piece of string question but I wouldn't want to have to put it on 8 hours before needed for instance... I forgot to mention I have Solar PV as well so in the summer a lot of the electric would be free.

If you get a 4kW output heatpump, then the heat will be the same as 2 2kW fan heaters while getting the room up to temp. You'll just have to estimate whether you think a couple of 2kW fan heaters would do the job well enough for you.

These don't suffer the same disadvantage as air to water heatpumps, where the circulating water is heated to a lower temperature than say a gas boiler, and therefore has to either have special radiators and/or the heating on most of the time.

The advantage of an air to air is that it will automatically maintain the set temp very efficiently, by varying the heat output, rather than turning itself on max then off for varying periods (assuming you get an inverter type). It's a diy job if you're quite handy (so I've been told!) - you can rent the vacuum pumps and if necessary, refrigerant top up or bleeding gear.

bernithebiker

I've installed a few 4 and 5kW air/air heat pumps in our houses, and I think they're great. Cheap and so far reliable, and not noisy. One is a Mitsubishi 4.8kW Hyperheating model that I got for £1200. For another £100 I got 4m of pre-charged piping for it, so you just connect up and go, super easy, the only 'tricky' part is drilling the 68mm hole for the 2 pipes, cable and condensate tube.

TiredGeek

Have a look on ebay for DIY units. £399 buys you a 2.8kw model, just plug in the cables and pipes and away you go

reeac

smartn wrote: »

Any ideas as to how long it would take to heat/cool? Bit of a how long is a piece of string question but I wouldn't want to have to put it on 8 hours before needed for instance... I forgot to mention I have Solar PV as well so in the summer a lot of the electric would be free.

Would you need the heat from the heat pump if the PV panels are giving an output? If it's sunny enough you might need to use the heat pump in reverse for air con., I suppose.

Cardew

reeac wrote: »

Would you need the heat from the heat pump if the PV panels are giving an output? If it's sunny enough you might need to use the heat pump in reverse for air con., I suppose.

On cold bright days in winter you can still get good output from PV panels, and any electricity available for the heat pump is a bonus.

reeac

Cardew wrote: »

On cold bright days in winter you can still get good output from PV panels, and any electricity available for the heat pump is a bonus.

Yes, I know [ I have a PV system]. Just messing about.

Andy_WSM

Indeed, I've had about 4 hours of free heat today from my air-air heat pump. Sunny, but cold. 12kWh of electricity from the PV has come in very handy though

smartn

Many thanks for all the replies. One thing that is concerning me now is the noise generated by the external units - I really don't want to do anything to upset our neighbours. Could anyone confirm the noise levels are acceptable both internally and externally.