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

[cortejuan]

Hi,

I see that you are going to the end of your ideas ...

I have a question regarding temperatures or rather the measurement method. It is (for me) necessary to measure the temperature under shelter, that is to say that the sensor must be protected from radiation. I made a case with a PVC tube of small diameter, pierced with multiple slots, closed on the top and free below for the air to circulate. The thermistor is placed inside without contact with the walls. The results compared to a free sensor are very different. 35 degrees measured at 60 cm from the top of the greenhouse (direct sensor) and 25 degrees measured 30 cm lower under shelter. So pay attention to the temperatures measured. Direct measurements are always more marked (lower at night by radiation towards the sky, larger during the day by radiation from the sun on the sensor.

I became aware of this problem by noting that when the temperature reached 35 degrees (usual measurement therefore direct), the transfer in my tanks (see my thread on the heating by thermal buffer) remained weak in spite of the high temperature. It was while measuring under shelter that I understood that the air in the greenhouse was much cooler and explained the low transfer to my pad.

Between heating and air conditioning by thermal buffer and by heat pump, there is ultimately a lot of similarity so your project is for me super interesting.

cordially

[chatelot16]

it all depends on the size of the greenhouse, the power of the sun, the power pumped by the cap and the age of the captain

as long as the little sun that there is carries more heat than the cap does not pump, the cap in the greenhouse will be happy ... when the cap pumps too much and the temperature in the greenhouse is lower than the temperature outside the profit is a loss

solution, put the cap in the greenhouse but near the edge to drill holes and put shutters allowing to choose or pass the air

it is even possible to take air in the greenhouse and reject the cooled air out of the greenhouse

[Alain G]

Hi Christopher!

Your consumption drops and there is nothing rocket science that it happens because at warmer temperature the refrigerant becomes more gaseous and the pump pumps more gas than liquid which makes it consume less.

Can I place my outdoor unit in the attic, in a garage or in my attic?

It is absolutely not recommended to place your outdoor unit
elsewhere than outside

It is normal that they mention this but in your case the heat is renewed by the sun and I see no problem if you put the thermostat I mentioned above which will stop your heat pump below a certain temperature , and moreover by keeping the temperature lower the vegetables will produce more and better vegetables deceiving the plant on the period of the year when it produces diverting its biological clock announcing the summer or the strong heat means: "I stop produce".

[Did67]

it is even possible to take air in the greenhouse and reject the cooled air out of the greenhouse

Indeed, a track!

If the sun is shining and the evaporator rejects the air colder than the external air, it will be beneficial.

If it rejects the air hotter than the external air, no.

[PITMIX]

Hello
If you install the group in the greenhouse in air conditioning mode in summer you risk having problems on the condenser. You will have a hp at 55 ° C or R410A about 34bars. It's bad for the cop. Who says hp too high says bp too high therefore poor cooling of your room. Overheating of the compressor degradation of the oil etc ... In summer in my job the overheating at the level of the condenser represents 90% of breakdowns. The majority of air conditioning in our region are forecast for 30 ° c max.

[Christophe]

Hello
If you install the group in the greenhouse in air conditioning mode in summer you risk having problems on the condenser. You will have a hp at 55 ° C or R410A about 34bars. It's bad for the cop. Who says hp too high says bp too high therefore poor cooling of your room. Overheating of the compressor degradation of the oil etc ... In summer in my job the overheating at the level of the condenser represents 90% of breakdowns. The majority of air conditioning in our region are forecast for 30 ° c max.

Thank you for this technical detail but I do not intend to use the air conditioning mode in summer, I will not use this air conditioning exclusively for heating ...

But as the compressor is in the outdoor unit is there still a risk of premature degradation (we mentioned it above) or performance? Even in heating only?

[Christophe]

it is even possible to take air in the greenhouse and reject the cooled air out of the greenhouse

Indeed, a track!

If the sun is shining and the evaporator rejects the air colder than the external air, it will be beneficial.

If it rejects the air hotter than the external air, no.

Indeed I thought "sheathed" the air outlet but I am not convinced that the efficiency is so much improved and the investment is quite heavy anyway ... (especially since the instructions prohibit any obstacle 2m from the air discharge ...)

I have to make you the photos of the assembly so that you can see the position and the openings of the greenhouse ...

[Christophe]

The sun is here ...

Do you have ideas for an in-depth test protocol?

I can measure:
- T ° and% RH in the greenhouse
- Instantaneous and cumulative power consumption
- T ° and% RH in the interior room

For the T ° and% RH measurement I can do this with a long-term recording probe: https://www.econologie.com/shop/enregist ... p-192.html

Possibly: the T ° and the air flow of the indoor unit (see outdoor) to estimate the calorific power restored (or pumped)

[Alain G]

Hello
If you install the group in the greenhouse in air conditioning mode in summer you risk having problems on the condenser. You will have a hp at 55 ° C or R410A about 34bars. It's bad for the cop. Who says hp too high says bp too high therefore poor cooling of your room. Overheating of the compressor degradation of the oil etc ... In summer in my job the overheating at the level of the condenser represents 90% of breakdowns. The majority of air conditioning in our region are forecast for 30 ° c max.

Hi Pimix!

I work in a food factory and we have many refrigeration units, in winter we add freon (or coolant) because it condenses under intense cold on certain units whose compressor is installed outside which falls in low pressure shutdown, summer we remove because inversely we fall into high pressure shutdown.

Of course Christophe does not fall into this pressure range which could harm his unit and I will repeat myself that simply by installing a thermostat in the greenhouse in series with the one inside there would be no problem of gas pressure and problem with vegetables which could be too cold.

See you!

[Christophe]

Here are finally the photos of the assembly in the greenhouse:

General view of the greenhouse:



Installation of the exterior split:



(I still have to "assemble" the 2 pipes together)

"Diagram" of the air flow: