air con is this possible

[sadie]

I am thinking about updating our heating. Reversible climate control via a heat pump seems a possibility. We have an upstairs grenier(unused space) and my thinking was:

If the exterior unit could be put in this area would it help with the loss of efficiency I believe happens when the temp drops to zero and below? Does anyone envisage any problems with this idea?

Thanks in advance

[tonyv]

Ahh, yes, the alchemists dream. Something for nothing, but I'm afraid the answer is no, as it contravenes the first law of thermodynamics.

In order to benefit from your heating below, you'd need to insulate your loft, so that so that the downstairs doesn't lose heat to the upstairs. Ideally, your loft should be at the same temperature as the exterior, indicating zero heat loss from downstairs. In order to generate heat, the evaporator must cool down its

surroundings, i.e. your loft, making it cooler than the outside, so

you'd need to ventilate the loft. So, you might as well place the evaporator outside.

Alternatively, don't insulate your loft, so that the heat from downstairs flows upstairs, giving nice warm surroundings for the evaporator to generate heat for the downstairs. Unfortunately, even at its most efficient, the heat pump wont be 100%, so you'd be losing energy in that operation.

Sorry, it sounds good, but your idea won't work.

[Swissie]

sadie - sorry for the diversion- but do you have any idea what 'air con' means in French?

(air = look     as in   il a l'air stupide avec ce chapeau)  (con = twit with a wovel change!   so   il a l'air con  = he looks like a tw*t

thought best to warn you!     

[sadie]

The house is basically built from concrete and brick. The floors are concrete.The only wood seems to be in the roofing timbers.The grenier area never freezes. There is little or no heat coming up from downstarirs.

[mint]

Neighbour has just had this done.  Be warned (that is if you don't already know), the units are huge and hideous and very visible mounted on an outside wall!

But, that's just my opinion so please ignore me completely if you don't mind the looks of these things and feel that they would be a solution for you.[:D]

[sadie]

[quote user="sweet 17"]

Neighbour has just had this done.  Be warned (that is if you don't already know), the units are huge and hideous and very visible mounted on an outside wall!

But, that's just my opinion so please ignore me completely if you don't mind the looks of these things and feel that they would be a solution for you.[:D]

[/quote]

This is my point. The grenier in question is about 40m2 and so no outside visibility. I am sorry that  I am obviously not able to give a precise view of the situation.

[krusty]

I have two of these beauties on the outside of my house.[Www]

Sadie please be aware the external unit gives out a lot of water when in heating mode.

The inverter ones are more expensive but a lot more economical in running cost.

Mine was providing heat down to -12`c last winter.

[sadie]

So, is this idea a goer or not?

[krusty]

I am no expert , but I would say yes ......but make sure there is plenty of ventilation.

[MLongford]

No, it won't work.  While it will initially work for a very short period, an air source heat pump gets all its heat from the air surrounding the outdoor unit.  If you put this in your attic space and the same amount of heat isn't coming into the attice space as new heat (equal to the amount of heat your heat pump is taking out of the attic space) your attic temperature will drop and your unit will shut down.  The unit has to be outdoors so that it is surrounded with a constant supply of fresh air which carries new heat.  I have been doing some research along similar lines myself, and have decided to change my heating system to an air source unit with fan coils (they can be plumbed into your radiator pipework and will do heating and cooling).  We have a barn conversion and the attic space gets too hot in summer and the barn is difficult to heat in winter with our current woodburning set up.  I will be able to use my existing pipework if I switch systems.  This could be worth considering.  A geothermal unit with fan coils is another possibility.  I was recommended to a company in the Dordogne, and if you would like their details I can pm you.

[krusty]

Now I have had a sleep I remember the hospital where I used to work had some installed in the loft so as not to spoil the look of the building. But they did have ducting for the air in and out of the unit.Which confirms what ML said above you can not just plonk them in a loft space.