ᐅ Decentralized Air-to-Air Heat Pumps / Heating with Air Conditioners in Older Buildings
Created on: 10 Feb 2022 03:32
H
Hausbau_newH
Hausbau_new10 Feb 2022 03:32Hello,
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_new11 Feb 2022 13:44Hello,
thank you very much. We will proceed with the concept as discussed.
Are multi-split units worth it?
They require fewer outdoor units. However, I have heard that they are not as efficient as single units because even if only one indoor unit needs heating, the large compressor always needs to start.
These units are more expensive to purchase than individual ones, but probably have lower maintenance costs.
Thanks in advance for your replies!
thank you very much. We will proceed with the concept as discussed.
Are multi-split units worth it?
They require fewer outdoor units. However, I have heard that they are not as efficient as single units because even if only one indoor unit needs heating, the large compressor always needs to start.
These units are more expensive to purchase than individual ones, but probably have lower maintenance costs.
Thanks in advance for your replies!
Hausbau_new schrieb:
Are multi-split systems worthwhile? Yes, of course. They are the simplest solution to supply multiple rooms or floors using just one outdoor unit.
Hausbau_new schrieb:
That they are not as efficient as individual units, because even if only one indoor unit needs heating, the large compressor must start. With individual units, if you have several rooms, you might need three compressors running simultaneously, which causes losses inherent to the system. So?
Hausbau_new schrieb:
Energy consumption approx. 100 kWh per m² per year). Who says that, the energy certificate or actual consumption?
I would first calculate the heating load.
Hausbau_new schrieb:
The concept is quite suitable for our house, since we have many exterior walls without windows -> But that also means no solar gains. How old are the windows?
Calculate (or have it calculated) first, then take action (buy).
I see a potential “energy sink” here at first glance.
Where is the house located? In the cold east or the warm south?
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