Efficiency of Heliotherm flat collectors

Hello everyone,

we have installed twice the area of collectors compared to the living space.

best regards
Muxel

With a geothermal heat pump with a Heliotherm heating system? If yes, isn't the standard price usually calculated at one and a half times, and did you have to pay more because of that?

@ There are maintenance costs because the amount of coolant exceeds a certain limit, so regular maintenance is mandatory. How expensive that is depends on the company and your negotiating skills (there are several HVAC companies that are authorized to do this). Otherwise, the operational function is pretty clear to me (-> physics...).

If you have too little surface area, it cools excessively. The first disadvantage is obviously decreasing efficiency – although direct evaporators can still work reasonably well at quite low temperatures – but then the surface area (better said, the volume) also freezes (underground!). As a result, the ground moves (water expands again below 4°C) and can rise a few centimeters (the colder, the more). This also affects vegetation. For example, the grass then grows quite poorly for a long time in spring. In the case of too short a deep borehole, usually only the efficiency decreases.

I still need to take another look at the coolant loss (correct, right?). I can't imagine that something will need to be refilled in the medium term, or will it? With this technology, I would estimate about twice the living area anyway, then there shouldn't be a problem, right?

It is not about coolant loss, it is about the obligation to have the tightness checked, goog*** for example "direktverdampfer dichtigkeitsprüfung eg". And read up on it a bit. This has recently become somewhat more complicated (conversion to CO2 equivalent, etc.), but I am quite sure that with the amounts of coolant in the direct evaporator a regular inspection remains mandatory. Otherwise, a little bit of coolant is basically always lost, you will probably never get it completely tight. Refilling every who knows how many years doesn't cost that much.

I have read something about a mandatory tightness test, but nowhere does anyone who has had it done annually really say anything – is it perhaps just an assumption that this test must be carried out? Or does this test not have to be performed on all heat pumps, as I have read.

Can you tell me approximately how much refrigerant is contained in a heat pump operated with a direct evaporator system?