ᐅ Preheating the intake air of the outdoor unit of an air source heat pump?

Hello everyone,

we are installing an air-source heat pump, and I was wondering if anyone has ideas or examples on how to supply the intake air a few degrees warmer during winter?
Would it make sense to dig a trench and lay a DN200 (8 inch) sewer pipe there? Or to somehow enclose the outdoor unit or place a thermal cover around it for the winter?

I would have used the exhaust air from the mechanical ventilation with heat recovery, but unfortunately, that is located in the attic.

Maybe some ideas will come up.

Best regards
Almo

I think it doesn’t make sense to use a size around DN200 for the required air volume. It would need to be larger, but then comparatively little heat transfer would take place.

For comparison: air-to-water heat pumps designed for indoor installation have air ducts starting from 50x50cm (20x20 inches) and larger to be able to draw in the necessary volume.

Yes, the fan is not that size in the unit without good reason.

Mycraft schrieb:
Yes, the fan doesn’t have its size in the unit purely by chance.

The point about the airflow is correct, but the argument is not entirely accurate. The fan is also this large in order to provide the necessary flow at low speed, while maintaining low noise levels and, because of the low speed, a long maintenance-free service life. So, a large fan does not automatically mean a high airflow.

How much garden area do you have?
I would position the intake unit as far away from the house as possible and thus install the longest possible underground pipe for preheating.

Müllerin schrieb:
How much garden area do you have?
I would position the intake part as far away from the house as possible and thus lay the longest possible underground route for preheating.

My outdoor unit is located directly next to the boiler room, so the distance is very short (2m / 6.5 feet).