Clim reversible Airton in winter: ext. under a greenhouse?

Heating, insulation, ventilation, VMC, cooling ... short thermal comfort. Insulation, wood energy, heat pumps but also electricity, gas or oil, VMC ... Help in choosing and implementation, problem solving, optimization, tips and tricks ...
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Clim reversible Airton in winter: ext. under a greenhouse?




by Christophe » 25/03/13, 15:18

As for Maloche at the time (see this topic https://www.econologie.com/forums/clim-rever ... t8616.html ), I am planning to install a small air to air heat pump to make additional heating. On paper a model like this should go:

Image

Power in cooling mode: 3 500 W. Power in heating mode: 3 700 W. Gas HFC R410A. COP: 3,95 / ERA: Interior noise 3,79: 28 dB Designed to operate at a maximum temperature. -15 ° C. With remote control, installation accessories and electrical wiring.


At 0.25 € / kWh with a COPA of 4, this gives a price of the useful kWh of 0.063 € / kWh which corresponds to a fuel oil price of 0.063 / 0.8 = 0.078 is 0.78 € / kWh so it is kif kif with the oil at the current price even with electricity 2 times more expensive than in France ... well that's not what interests me in this subject ...

Attention it's a little headache ...

As here it can be cold, I thought place the outdoor battery in a greenhouse next to the house that I had renovated some time ago see details here: https://www.econologie.com/forums/renovation ... t7461.html (The vertical glazed parts are exotic wood double glazing so good enough inertia and insulation ... for a greenhouse)

Image

The greenhouse is exposed east and receives the morning sun until about noon between the 2 equinoxes. It rises to more than 40 ° C in summer (open doors).

Is it necessary to place the external battery in this greenhouse?

Advantages:
a) gain of the slightest small ray of sunlight to increase the "outside" T ° and therefore the performance of the heat pump
b) average temperature over the year improved finally to see next a) disadvantages
c) avoids overheating in the greenhouse in summer

Disadvantages / fears:
a) despite the higher T ° in the greenhouse, in winter, without sun, it may cool faster than the ambient air and thus degrade performance (but the greenhouse can be opened / ventilated)
b) the afternoon it may be less interesting than if I placed on the sunny west wall.
c) in case of no need for heating in summer: how does an external battery with more than 40 ° C and in the humidity of a greenhouse behave? Lifetime?

That's all I see for the moment ... but you'll probably have other ideas ...

Thermally, a solution would be to put a regulation on the T ° of the greenhouse (to stop below a certain greenhouse temperature whatever the T ° outside?)? As this would tighten it would have time to warm up again and the average COPA would be improved?

In short I paddle a little there ... so your opinion should enlighten me ...
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by Christophe » 27/03/13, 21:27

No opinion? No idea? :|
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by Ahmed » 27/03/13, 21:46

From what it seems to me, it takes a large volume of air to operate a PAC (or water in the case Water / air), so locate the exchanger in such a limited space appears to the least hazardous, especially with a fall / winter as gray as this year ...
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by Christophe » 27/03/13, 21:48

It is true but ... nothing prevents to leave the door open in the case where the greenhouse would cool too much ... Also the last portion of roof (on the right the finest) is removable, which makes it possible to make An air current.

The idea is above all to gain COP by raising the average "outside" T ° in spring and summer ... I have little hope of gain for winter ...
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by Ahmed » 27/03/13, 22:01

What is the interest of a summer PAC?
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by raymon » 28/03/13, 08:36

I think the greenhouse is a good idea just open the doors if you realize that it is colder in the greenhouse than outside. I wanted to do the same thing by putting the outdoor unit in a big shed but my installer thought it was a bad idea but good. An idea: if you put a fan on one of the opening of the greenhouse that starts when the indoor temperature is below the outside temperature with an additional conso of a few watts you could have an interesting gain.
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by Did67 » 28/03/13, 10:50

There are two questions:

a) what is the solar energy that the greenhouse can capture ??? Is it of the same order of magnitude as what the CAP draws ???

Otherwise, it is better to let your evaporator extract calories from an "infinite" air rather than to stuck it in a confined space, whose balance would be negative, and therefore whose temperature would drop inexorably!

b) without encouraging the passage of "confined atmosphere in the greenhouse" / open greenhouse, this will not work!

As soon as the sun goes down, as soon as it is gray, your closed greenhouse turns into a cold room, colder than the outside atmosphere ... You lose.

When there is sunshine, you only win if the solitary airports are higher than the CAP withdrawals: there, the temperature in the greenhouse would be higher than that of the ambient air, and your COP improved.

I do not believe much! It seems to me that you will be more often a loser than a winner, unless you take care of it continuously!
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by Christophe » 28/03/13, 11:26

Ahmed wrote:What is the interest of a summer PAC?


None, I made a slip of the tongue, probably because after this shitty winter, I'm waiting so much for the summer that my subconscious has bugged lol ...

I obviously wanted to write "spring and autumn"! Mid season what ...
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by Christophe » 28/03/13, 11:32

Did67 wrote:a) what is the solar energy that the greenhouse can capture ??? Is it of the same order of magnitude as what the CAP draws ???

Otherwise, it is better to let your evaporator extract calories from an "infinite" air rather than to stuck it in a confined space, whose balance would be negative, and therefore whose temperature would drop inexorably!


It is enough to measure the surface of the greenhouse and to multiply it, say by 300W / m² on average during mid season when the sun shines?

The greenhouse is much more than 10m² in area ... so there is "margin". I will measure it precisely ...

Did67 wrote:b) without encouraging the passage of "confined atmosphere in the greenhouse" / open greenhouse, this will not work!

As soon as the sun goes down, as soon as it is gray, your closed greenhouse turns into a cold room, colder than the outside atmosphere ... You lose.

When there is sunshine, you only win if the solitary airports are higher than the CAP withdrawals: there, the temperature in the greenhouse would be higher than that of the ambient air, and your COP improved.

I do not believe much! It seems to me that you will be more often a loser than a winner, unless you take care of it continuously!


Yes it is to be feared, so we can automate 2 way (without having to open the greenhouse):

a) time schedule (only run until noon)
b) regulation on the temperature of the greenhouse (stop everything when it is lower than a certain temperature or lower than the outer temperature)

We can easily combine the 2 ...
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by Gaston » 28/03/13, 11:37

Agree with Did67, with a flat: it seems easy to automate the opening of the greenhouse when the outside temperature is higher.
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