ᐅ Outdoor unit of air-to-water heat pump is smoking and steaming

Created on: 6 Jan 2021 18:24
T
Tx-25
Hello everyone. Our air-to-water heat pump has been in use for about half a year now. We recently noticed some hissing noises coming from the outdoor unit. It sounds similar to a truck brake losing pressure, but somewhat quieter. I have heard this noise three times so far. The last time, I happened to be outside near the outdoor unit. The noise appeared, and the fan stopped running—not suddenly, but gradually. I stood right in front of the unit to see what was happening. After a few seconds, the fan turned on again. At that moment, a kind of "cloud" appeared. Not a real cloud, more like when you blow dust off an old book. It didn’t smell like something burning, but more like intense heat being generated. I hope you understand what I mean. How would you assess this situation? So far, neither the heating system nor the unit has shown any error messages. The heating is working perfectly. Because of the weather, the outdoor unit is practically running almost non-stop. Could this be some kind of overheating that causes the fan to briefly switch off?
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WilderSueden
7 Jan 2021 12:45
In the end, it’s quite theoretical when it comes to the sun. The solar thermal system for the gas heating hardly contributes anything in winter—precisely when it would be useful. I read recently that we had around 15 hours of sunshine throughout December. As a result, the photovoltaic system also contributes relatively little to powering the heat pump. You can make both options look good on paper or not.

On the cost side, the gas boiler is currently probably still at an advantage. However, the political will seems to be moving in a different direction. For an unrenovated older building, this will definitely not be easy in 10 years. An efficient new build presents a completely different calculation since it simply loses less energy. However, every calculation becomes irrelevant because it has to estimate future gas and electricity prices.
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guckuck2
7 Jan 2021 12:57
Therefore, it is wise to consume as little energy as possible. Then, the price becomes relatively unimportant.
Anyone who regularly spends around 250€ per month on fuel will already notice the impact of the CO2 price in 2021. The same applies to the house.
Mycraft7 Jan 2021 13:07
WilderSueden schrieb:

The solar thermal system of the gas heating provides practically nothing in winter, which is exactly when it would be useful.
Only new findings today here: heating water with solar energy makes sense only in winter. The remaining three-quarters of the year, it does not?

Certainly, solar thermal systems ultimately provide less than photovoltaic panels. However, they are also less expensive to purchase and install, partly because they require far less surface area.

Everything really must be calculated individually and not generalized. Every house is different, and depending on the conditions and possibilities of the homeowners, one or another setup can be the more cost-effective option.
Tolentino7 Jan 2021 13:18
It would be great to have a plot of land with a thermal spring...
Mycraft7 Jan 2021 13:47
In Scandinavia, this is quite common. 🙂
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WilderSueden
7 Jan 2021 18:07
Mycraft schrieb:

Only new insights today: heating domestic hot water using solar energy only makes sense in winter. Not for the remaining 3/4 of the year?
A colleague said she can draw tea water directly from the tap in summer 😉

But aside from that, in summer you only need a very small portion of the hot water for showering, whereas in winter the demand for heating is significantly higher. But you surely understand what I meant.