ᐅ Screed Heating Protocol Using External Devices or Heat Pump?

Hi everyone,

I have a more general question and would like to hear your opinions.

I’m about to start with the screed and have two options for the drying process starting from calendar week 6 (so basically in mid-winter on paper):

1. Heating with the air-source heat pump iPUMP ALM 2-8
2. Heating with external devices (an additional cost of €675 net)

The area is about 270 m² (2900 sq ft) (basement, ground floor, upper floor).

Which option would you choose, considering the season, area, and performance of the heat pump?

Thanks and best regards

With heat pumps using ground probes or slinky ground collectors, soil freezing can sometimes be an issue.

This does not happen with an air-source heat pump; it can simply run with low cycling to efficiently deliver enough heat to the house.

Efficiency might not be optimal under these conditions, BUT it is still significantly better than that of a dehumidifier. In addition to the 675€ cost, there would be some additional electricity consumption measured in a few MWh.

Felix1117 schrieb:

What would you choose considering the season, area, and performance of the heat pump?

For me, it’s clearly drying with the heat pump. I can’t see any reason to rely on external devices when you have a functioning air-to-water heat pump. Ventilation should also work very well since the outdoor humidity is usually very low in winter.

If the builder agrees, then with a heat pump. Some builders don’t want that because they fear the heat pump can’t handle it – which, of course, is nonsense, but what can you do.
Mine would have done it, but back then the heat pump was unavailable for months.
The consumption was over 8 MWh. With a heat pump, it probably would have been only half.

Ok, yes, he would do it, but he says that the heat pump tends to lose lifespan as a result.

Felix1117 schrieb:

Okay, yes, he would do it, but says that the heat pump tends to have a reduced lifespan because of it.

What exact reduction are we talking about if it runs for a longer period? It also depends on the flow temperature and thus the load on the heat pump.

I would coordinate with the screed installer and heating engineer about which heating-up protocol to use. Many protocols—like the rough guidelines often used for heat pump construction—are still based on older new builds and gas heating systems with high flow temperatures (sometimes 45-50°C (113-122°F) for functional heating). Nowadays, in new constructions, it should be a special case for the heat pump to reach around 35°C (95°F) (I typically have a flow temperature of 29-30°C (84-86°F) for an indoor temperature of 22°C (72°F) when outside temperatures are between -5 and -10°C (23 to 14°F)). Gradually, this is shifting toward functional heating reflecting actual conditions, which is also the purpose of functional heating—meaning significantly lower heat pump output.

My own protocol specified a maximum temperature of only 35°C (95°F) for a short time. Therefore, there was no loss of lifespan at all.