Investing in a heat pump - is it worth it?
What savings does a heat pump generate compared with traditional systems?
For new buildings with insulation compliant with WT 2021 and areas of 100, 200 and 300 m², the calculated heat demand will be about 3.5 kW, 7 kW and 10.5 kW respectively - corresponding to a heat energy demand of about 5,250 kWh, 10,500 kWh and 15,750 kWh.
The electricity demand of MultiTherma heat pumps (at the real, achieved efficiencies and with correct sizing, SCOP 6.2) will be respectively: 846, 1 694 and 2 540 kWh. An electric heater will use 5,250 / 10,500 / 15,750 kWh, while a gas boiler would burn about 525 / 1,050 / 1,575 m³ of gas to cover this energy.
| House 100 m² | House 200 m² | House 300 m² | |
|---|---|---|---|
| Heat pump [1 zł/kWh] | 846 zł / season | 1 694 zł / season | 2 540 zł / season |
| Ogrzewacz elektryczny [1 zł/kWh] | 5 250 zł / season | 10 500 zł / season | 15 750 zł / season |
| Kocioł gazowy [3,5 zł/kWh z opłatami] | 1 837 zł / season | 3 675 zł / season | 5 512 zł / season |
How long does the payback on a heat pump take?
The difference in running costs between a heat pump and an electric heater and a gas boiler:
| House 100 m² | House 200 m² | House 300 m² | |
|---|---|---|---|
| vs electric heater | – 4 404 zł / season | – 8 806 zł / season | – 13 210 zł / season |
| vs gas boiler | – 991 zł / season | – 1 981 zł / season | – 2 972 zł / season |
At an average purchase cost of a higher-class heat pump (PLN 20,000 / 23,000 / 24,000 net), the cost of electric heaters (PLN 300 / 700 / 1,000) and gas boilers (PLN 2,000 / 3,500 / 5,000), the simple payback time looks as follows:
| Payback time | House 100 m² | House 200 m² | House 300 m² |
|---|---|---|---|
| pump vs electric heater | 3,7 mo. | 2,5 mo. | 1,74 mo. |
| pump vs gas boiler | 18,1 mo. | 9,8 mo. | 6,4 mo. |
With every month beyond the calculated payback time, a heat pump - assuming the efficiency of the MultiTherma range - brings a gain over traditional heat sources.
How do building size and insulation affect the payback time?
A heat pump costs more than a gas boiler, so for low-output devices and small buildings the payback can be longer. However, the price difference between successive pump outputs narrows as output rises within the range. Regardless of output and insulation, sooner or later there comes a point where the pump brings savings every month. Moreover, good thermal insulation reduces the output demand, which lowers both the pump purchase cost and the running cost - so it is worth aiming for the best possible building insulation.