Air to Heat pump for conservatory

[zappa]

Thinking of going for this type of installation for a proposed 6 x 3.5m conservatory as opposed to UFH/rads.

Any thoughts / experience of these? Poss 3.5kW model?

http://www.comfortableclimates.co.uk/Panasonic Etherea Heat Pump - Aircon.html?category_id=94

Thanks

 

[Corgigrouch]

Go for the 5.2kW or the 6kW else you'll be disappointed when it's cold outside... Panasonics are OK

 

[Boilerman2]

And it'll be luverly and COOL in the Summer too!!
Good Choice

 

[zappa]

Go for the 5.2kW or the 6kW else you'll be disappointed when it's cold outside... Panasonics are OK

That big really? They chuck out 8kW heating. Thought 6kW might do? Are these a certifiable installation etc? Will be providing the separate supply from new RCBO which is Part P etc etc

 

[Corgigrouch]

No a 3.5kW unit will produce 3.5kW assuming the weather is mild (I think that they rate them at an ambient of around 8C but I can no longer remember) As the ambient air temperature falls so does the output.... Add to that the number of defrost cycles increase in humid weather and your 3.5kW unit will no longer 3.5kW........Further add to that the horrendous heat loss of a plastic greenhouse, then you will need more output...

Don't get me wrong, for a conservatory, an air to air heat pump is the ideal heating device....

 

[zappa]

Thing is.... I'm not really understanding what the 3.5kW is relevant to? Are you saying that this is totally dependant on the outside temp? Looking at the max heating output of the CS-E12MKW unit from the data sheet it says 6kw? With a COP of just over 4, then I'm ,looking at power consumption of about 1.5kw at a temp of 8C outside and the lower it drops the less heat it will chuck out?

Thanks again.

 

[Corgigrouch]

The rated output for the CS-E12MKW is 3.5kW...... The Rated output for the CS-E21MKW is 6kW...... Since these are inverters, then they don't always run at full speed and so once the room is close to its set point then the system will use less energy however there are many factors that affect the efficiency.... It is a common mistake for folk to buy a unit rated at 3.5kW only to discover that the output decreases as the outside temperature falls.... It isn't a case of them not working, it is a case of sizing them correctly.

If you fit a 6kw unit then in normal UK weather it will heat at or close to it's stated COP, BUT unless the heat load calls for 6kW then the unit will reduce it's output to suit what is needed..... Normal rooms are easier to size as they lose their heat at a far lesser rate but a conservatory bleeds heat at an alarming rate and so tends to need a unit with a larger output

 

[zappa]

See what you're saying but.... where does this 6kW max heating output figure come from?

Thanks again!!

 

[Corgigrouch]

I got the output from the price list in your link.... Normally the number in the model number refers to the output in BTU..... 12 equates to 12000btu which equates to 3.5kW approx..

I had a looksee down the list and it seems like the guy who made the website can't type straight and the spec table is wrong

 

[stem]

I've got an air source heat pump in my office. During the winter, when the outside temperature is above 5 degrees it works really well, however as the outside temperature drops close to, or below freezing heat output drops off rapidly, which is a bit of a nuisance as that's when you need more heat indoors.

When used for heating, the outdoor unit blows out cold air, so even on days where the outside temperature is above freezing, because of the extra cooling, it can ice up, so sometimes upto 15 minutes of every hour it is in 'defrosting mode'. During this time no heat whatsoever is emitted.

Last year when the outside temperature was -10 to -15 degrees I had to leave it on 24/7 to maintain 21 degrees inside, even then, occasionally it had fallen to 19 first thing in the morning. If it was turned off overnight it was 16 in the morning only managing to reach 19 degrees after 6 hours.

I should add that the office is part of a new build (2007) on a business park. It has fabulous insulation and has gained an accolade from BREEAM. So it does retain heat that is put into it.

So I believe the advice you have been given is good. Go for the bigger unit especially if you don't intend to heat the conservatory permanently and need a quick warm up. Inverter control means that you won't use anymore power than you need in milder weather.

 

[DeltaT2]

Ach, save your money mate, fit one of these bad boys;
http://www.cooleasy.co.uk/categories/Wall-Mounted/Chigo-Fixed-Speed/

We've fitted 100s in conservatories & they're great value for money, the COP holds up very well at lower temperaturers.

 

[Corgigrouch]

Delta, I wouldn't fit one of those in my dogs kennel....

 

[big-all]

for the best part of £1000 for 3.5kw not overly cheap
assuming 0.75kw running costs for say an average 2.5kw output thats about 25p an hour saved thats assuming around 15p a unit so say an average 10 hrs a day thats £2.50 for say 5 months = £375 so 3 years payback if no maintainance required

of course these are just my guess but you get the idea

and gas will give you similar savings in a lot off situations or very close as a kw off heat from gas is around 1/3 that from electric

 

[DeltaT2]

Delta, I wouldn't fit one of those in my dogs kennel....

More fool you mate, they're great wee split units & we've not had one problem with them out of the 100 or so we've fitted. In fact I don't think one of our customers has even had to change the remote control batteries!! We've two in our Showroom on Energy Meters & we're getting about 2.8-3 COP on some of the coldest days we've had here in Scotland.

There's many reports on-line about inverted HPs not been worth the money, they just don't save enough to justify the extra cost!! I'm no nut eating tree hugger eco tw.t, I'm just in it for the money & we could sell these Ch.nky units all day long - they're just so cheap & reliable.

Most of the Greenwash Used Carsalesmen, that were conning the public with their duff figures, are now on the dole since the FIT & RHI was cancelled, so life goes back to normal for all us trained & qualified Tradesmen............Karching!! Karching!!!££££££££££...........

 

[Kev F]

Fitted similar unit in a conservatory ( customer happy to take risk as cheap) I'm very pleased. It works as well as many other expensive options