ASHP Case Study No.1
Property Type:
1940s, 3-bed semi, 128 m2 floor area. Previously heated by a gas combi boiler. Owner had already topped up loft insulation to 350 mm, installed cavity wall insulation, solar PV and a battery storage system.
Heat Pump Installation:
Mitsubishi Ecodan Ultra Quiet 11.2 kW ASHP, hot water tank in utility room, 9 new radiators (most rooms), 45 degrees C flow temperature, £13,000 cost (without any grant).
Owner Experience:
Installation times: “It might take longer than you expect to get a quote, to do the design work. Don’t wait until your heating system has died, you can’t do it in a hurry”.
Warmth: “You can’t tell the difference…the house is just as warm as it was before”.
Noise: “It does make a noise, but you don’t really hear it from inside and it’s not very loud.”.
Predicted v Actual Performance: Average gas consumption before the heat pump was installed was 14,906 kWh per annum. Predicted electricity consumption for the ASHP was 3,911 kWh per annum. Actual electricity consumption over the first year was 3,394 kWh.
Cost of Running: Annual electricity costs for the ASHP were £1,246 compared to £1,718 gas heating costs. Costs are based on the 1st October 2022 – 30th June 2023 Energy Price Guarantee tariffs (36.7 p/kWh for electricity and 10.9 p/kWh for gas) and account for the saving on gas standing charge.
