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?
D
Daniel-Sp6 Jan 2021 21:04untergasse43 schrieb:
No water leaks from those. They simply get very cold so that the inside can warm up (like a reversed refrigerator). Moisture from the air freezes on them. This then has to be evaporated with considerable energy input so that air can flow through the fins again.
I was walking the dog earlier in the new development area. From various spots on the properties, these little clouds appeared. It’s quite silly when expensive electricity is used to heat the fins so they then do the exact opposite to warm the house. Besides that, it looks pretty ridiculous. I just can’t warm up to those things (haha). Well,
It’s a bit different.
During defrosting, the cycle is reversed, and the required energy is taken from the warm screed. Actually, nothing evaporates there. The ice is melted at screed temperature. That’s why there is also a condensate drain. Modern units don’t really use electricity for this process. And yes, this also creates some noise…
untergasse43 schrieb:
Apart from looking quite ridiculous, I just can’t get comfortable with those things (haha).Me neither, but we’re having one installed anyway. What other options are there right now? Apparently, you can’t meet the required energy standards with a gas heating system anymore.
And with photovoltaic panels, you can probably operate them cost-effectively.
However, I find it quite troubling how everything in this country is being reduced to electric energy,
while nuclear and coal power plants are being phased out at the same time.
Olli
This is what some home builders have told me.
At my current preferred general contractor, a heat pump is also standard. I didn’t even ask about a gas heating system anymore.
However, I could also imagine that a gas heating system combined with solar water heating might be suitable.
Olli
At my current preferred general contractor, a heat pump is also standard. I didn’t even ask about a gas heating system anymore.
However, I could also imagine that a gas heating system combined with solar water heating might be suitable.
Olli
@Olli-Ka
Yes, it works if you actually calculate it. If you just estimate roughly, it obviously won’t be accurate. Just compare everything directly: investment, operating costs, etc., and don’t forget the interest rates. Then compare over a 20-30 year period. Keep in mind that with a gas boiler, you’ll probably only need one for the entire period, whereas with heat pumps, it might be two, or three in the worst case.
Really? So modern units no longer require electricity to pump the refrigerant back and forth? That’s actually the main argument against air conditioners. I wasn’t aware that phase changes could now happen spontaneously in both directions.
Yes, it works if you actually calculate it. If you just estimate roughly, it obviously won’t be accurate. Just compare everything directly: investment, operating costs, etc., and don’t forget the interest rates. Then compare over a 20-30 year period. Keep in mind that with a gas boiler, you’ll probably only need one for the entire period, whereas with heat pumps, it might be two, or three in the worst case.
Daniel-Sp schrieb:
Modern units generally don’t rely on electricity.
Really? So modern units no longer require electricity to pump the refrigerant back and forth? That’s actually the main argument against air conditioners. I wasn’t aware that phase changes could now happen spontaneously in both directions.
You could focus on this characteristic of an air-to-water heat pump. However, defrosting is already accounted for in the now quite impressive annual performance factor of newer units and can be considered negligible in the overall energy balance.
After all, nobody complains about the energy consumption of a car’s rear window defroster when at the same time two-thirds of the energy from gasoline combustion is lost as heat to the environment ;-)
After all, nobody complains about the energy consumption of a car’s rear window defroster when at the same time two-thirds of the energy from gasoline combustion is lost as heat to the environment ;-)
Similar topics