ᐅ Air-to-water heat pump very loud

Our air-to-water heat pump works without the electric heating element, which I have turned off. Even at -21°C (-6°F) it was not a problem. The heating element is only needed for hot water. There is also a noise reduction mode, where the heating element runs and the compressor output is reduced. However, this does not cause any cooling.

Comparing it to an electric heater is obviously nonsense and sounds like half-knowledge from local gossip 😉. The efficiency actually sometimes increases again because the heat pump has to defrost more often near the freezing point. With colder, drier air, it improves slightly again.

A lot has already been written here, but very little with a solid technical basis. Therefore:

• No single system today should solely reach the guideline values of the Technical Instructions on Noise Protection (TA Lärm). Otherwise, each additional system would lead to an exceedance of these guideline values.
• A single system should (technically correct here: must) be at least 3, preferably 6 dB below the nighttime guideline limits.
• Building regulation offices and local environmental protection authorities have largely overlooked the noise issues related to air-to-water heat pumps in recent years and, in some cases, still do. According to current regulations, there is a harsh awakening for many current and future operators of air-to-water heat pumps, following the authorities’ prolonged negligence.
• About 35 dB in front of bedroom windows in 400 m² (4,300 ft²) new building plots, of which more than 60% are heated with air-to-water heat pumps, is partly unrealistic.

Oh man ... complicated

Knallkörper schrieb:
Who should the neighbor contact if it gets too loud? The building authority / planning department? Or the property owner?

There is no fixed procedure here. Common sense would suggest first approaching the operator—that is, the neighbor. However, contacting the building code enforcement office, the police, or filing an injunction has sometimes been the initial course of action.
In general, if you are the person being disturbed by an existing installation, you initially have the burden of proof. This means using a proper measurement point as per section 29, not a smartphone app.

MayrCh schrieb:
There has already been a lot written here, but only little technically sound information. Therefore:

• No single system is allowed nowadays to fully exploit the guideline values of the TA Noise regulation alone. Because in that case, every additional system would lead to an exceedance of the guideline values.
• A single system should (technically correct here: must) undercut the nighttime guideline values by at least 3 dB, preferably 6 dB.
• Building regulation offices and lower environmental protection authorities have completely overlooked the noise issues of air-to-water heat pumps in recent years and, in some cases, still do. According to current legal conditions, after this regulatory “sleeping beauty” phase, many current and future air-to-water heat pump operators face a rude awakening.
• ~35 dB in front of bedroom windows on 400 m² (4,300 ft²) new build plots, of which more than 60% are heated via air-to-water heat pumps, is partly unrealistic.

A Rotex HPSU Compact with an 8 kW capacity generally undercuts the guideline values in general residential areas at a distance of 5.80 m (19 feet) by 6 dB, both during protected quiet hours in the daytime and at night.

If the system is located 3 m (10 feet) from the neighbor and the neighbor respects the 3 m (10 feet) setback distance, then the above requirements are already met. Even small shared streets in residential areas are about 6 m (20 feet) wide. If the heat pump is installed at the front of the house and everyone observes the required setback distances, there is at least about 12 m (40 feet) distance to the opposite side.

I would not exaggerate here. Of course, poorly, incorrectly, or unprofessionally installed systems are definitely problematic. It is important that a qualified company handles the installation, with sound decoupling of the base slab, and so on.

Grym schrieb:
A Rotex HPSU Compact with 8 kW capacity already falls below the guideline values for a general residential area at a distance of 5.80 m (19 feet) by 6 dB

Where do you know that from? Measured?