ᐅ Decentralized Air-to-Air Heat Pumps / Heating with Air Conditioners in Older Buildings
Created on: 10 Feb 2022 03:32
H
Hausbau_new
Hello,
We have bought a house with about 150 sqm (1,615 sq ft); the exact year of construction is not clear, but the last renovation was around 2000 (energy consumption approximately 100 kWh per sqm per year). The house currently has no heating system, so we need to install one. Previously, heating was provided by night storage heaters.
Given the current energy prices, we tried to calculate the cheapest way to produce heat per kWh.
The following assumptions:
Heating oil price per liter 0.94 Euro
Gas price per kWh 0.11 Euro
Electricity per kWh 0.33 Euro
This gives me the cost per kWh of heat as follows:
Heating oil boiler: 0.096 Euro (assuming 1 liter heating oil produces about 9.8 kWh heat)
Gas boiler: 0.11 Euro (assuming 10 kWh gas = 1 m³ gas = about 9.8 kWh heat)
Air-to-air heat pump (SCOP value 4): 0.083 Euro (assuming 1 kWh electricity = 4 kWh heat)
According to this calculation, with current energy prices, the air-to-air heat pump would be the cheapest way to heat a house. Or have I made a mistake in the calculation somewhere?
This concept suits our house quite well, since we have many external walls without windows — so the outdoor units won’t be heard much — and there is already a separate electrical circuit from the night storage heaters. This concept would also be convenient for us because we would save on pipework. Additionally, we find the option attractive because we plan to reduce electricity costs with photovoltaic panels. We are aware of the comfort drawbacks (when heating, a fan runs generating some noise, and there is no radiant heat, as only the air is warmed).
Before implementing this concept, I wanted to ask if there are any errors in my calculations or other opinions on why this approach might be unsuitable.
Thank you very much.
We have bought a house with about 150 sqm (1,615 sq ft); the exact year of construction is not clear, but the last renovation was around 2000 (energy consumption approximately 100 kWh per sqm per year). The house currently has no heating system, so we need to install one. Previously, heating was provided by night storage heaters.
Given the current energy prices, we tried to calculate the cheapest way to produce heat per kWh.
The following assumptions:
Heating oil price per liter 0.94 Euro
Gas price per kWh 0.11 Euro
Electricity per kWh 0.33 Euro
This gives me the cost per kWh of heat as follows:
Heating oil boiler: 0.096 Euro (assuming 1 liter heating oil produces about 9.8 kWh heat)
Gas boiler: 0.11 Euro (assuming 10 kWh gas = 1 m³ gas = about 9.8 kWh heat)
Air-to-air heat pump (SCOP value 4): 0.083 Euro (assuming 1 kWh electricity = 4 kWh heat)
According to this calculation, with current energy prices, the air-to-air heat pump would be the cheapest way to heat a house. Or have I made a mistake in the calculation somewhere?
This concept suits our house quite well, since we have many external walls without windows — so the outdoor units won’t be heard much — and there is already a separate electrical circuit from the night storage heaters. This concept would also be convenient for us because we would save on pipework. Additionally, we find the option attractive because we plan to reduce electricity costs with photovoltaic panels. We are aware of the comfort drawbacks (when heating, a fan runs generating some noise, and there is no radiant heat, as only the air is warmed).
Before implementing this concept, I wanted to ask if there are any errors in my calculations or other opinions on why this approach might be unsuitable.
Thank you very much.
H
Hausbau_new12 Feb 2022 03:08driver55 schrieb:
Who says, the energy performance certificate or the actual demand?
I would first determine the heating load.
That also means no solar gains. How old are the windows?
Calculate first (or have it calculated), then act (buy).
I see a potential "kWh trap" here.
Where is the house located? In the cold East or the warm South?Thank you also for this criticism.
The heating load was determined both by calculation and via the energy performance certificate, and the values were close to each other between 14,000 and 15,000. The windows are double glazed and also from 2000.
However, the heating load is irrelevant for the calculation mentioned above. It was about determining the cheapest kWh of heat based on current prices of the sources. So even if the heating load value is incorrect and the actual value is much higher, you should still look at how to produce heat cheaply at the moment.
Later, the heating load will be relevant for sizing the boiler.
I like the idea of calculating with an SCOP value of three, as this is a more conservative approach.
The house is located in Berlin.
Hausbau_new schrieb:
The house is located in BerlinIf natural gas is available, you are no longer allowed to install oil heating or a liquefied petroleum gas (LPG) tank.Your options are then limited to gas or electric heating systems.
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