ᐅ Heating up the screed – heat pump or portable heater?

Hello everyone,

I have a question again because we are currently facing a problem, and the experts don’t completely agree.

We have installed underfloor heating over about 170 m2 (1,830 sq ft), and the screed will be poured next week. According to the screed installer, the heating can be started after about 7 days.

Our air source heat pump (9 kW output) installed outside would already be ready to operate by then, and until now, we thought it could be used to warm up the screed. However, we were recently told that the heat pump won’t be able to handle this at the current outdoor temperatures and that we cannot use it. Instead, we were advised to rent a mobile electric heating device (for example, a Hotboy) to warm up and dry the underfloor heating.

Another heating specialist was surprised and said the heat pump should be capable of doing this...

Is this really necessary? And why is it said that our heat pump can’t manage it? What has been your experience?

Of course, the heat pump should be able to handle that, if necessary with the electric heating element.
This was also done in our case; the (geothermal) heat pump was not fully operational yet, but the electric heating element was. The electricity meter does spin, but with the separate unit, it probably can’t be any different.

Thank you for the quick response! The electricity meter will definitely run in both cases... With the portable heater, the wallet also spins, due to the rental cost and the effort required to connect it.

Did you have the screed installed in the autumn as well?

WildThing schrieb:
thanks for the quick reply! The electricity meter will definitely run in both cases... With the portable heater, the wallet also spins because of the rental and the effort to connect it.

Did you also have the screed installed in autumn?

For us, the screed was installed in spring – we only had the frame completion ceremony on St. Nicholas Day.

Hello,

We had our screed installed in November 2014 and dried it using only the air-to-water heat pump.

During the drying heating phase, outdoor temperatures ranged between -10°C (14°F) and +5°C (41°F) – we only used the electric heating element for less than an hour right at the start of the heating system commissioning.

This was the fourth consecutive day with -10°C (14°F), and the house had cooled down accordingly. The rest of the drying process was handled easily by the air-to-water heat pump without any electric heating support.

Regards,

Dirk

Thank you, Doc.Schnaggls, so it would be roughly the same as with us....
We will call the customer service of our heating system again today and ask them directly how things stand... Let’s see how we end up handling it in the end.