ᐅ Is an air-to-water heat pump a practical option for renovating a listed building to meet Efficiency House standards (160% energy savings regulation)?
Created on: 14 Jan 2021 09:11
R
RomeoZwo
Hello everyone,
This is about the renovation of a listed single-family house for rental purposes. According to the energy consultant (an architect specializing in renovations), using an air-to-water heat pump is recommended because a gas condensing boiler would require significantly more insulation work (internal insulation of 8cm (3 inches) instead of 4cm (1.5 inches)) and thus reduce the living space. The air-to-water heat pump could be installed in the basement, with air intake and exhaust through the former coal window (basement top edge about 80cm (31 inches) above ground level). Photovoltaic or solar thermal systems are not possible due to heritage protection. Until now, I had assumed a gas boiler for the house since there is a gas connection in the street, although it has not yet been connected to the house (original heating was a central coal heating system, but unused and unoccupied for 30 years).
As a rental property, it is also interesting that the green/red political plans to impose the CO2 tax on landlords would not be problematic in this case, since electricity costs are charged directly to the tenant and therefore initially would not appear in the additional costs.
On paper, the air-to-water heat pump is clearly advantageous, but what is the reality here? In 2017, we chose gas for a new build due to the high electricity consumption. This is an old building that is allowed to have up to 60% more primary energy demand than a new build. Can the figures for the air-to-water heat pump be trusted to some extent, or will the electricity consumption be a disaster?
Thanks in advance for your opinions—I had never really considered an air-to-water heat pump before and therefore haven't looked into it much yet.
This is about the renovation of a listed single-family house for rental purposes. According to the energy consultant (an architect specializing in renovations), using an air-to-water heat pump is recommended because a gas condensing boiler would require significantly more insulation work (internal insulation of 8cm (3 inches) instead of 4cm (1.5 inches)) and thus reduce the living space. The air-to-water heat pump could be installed in the basement, with air intake and exhaust through the former coal window (basement top edge about 80cm (31 inches) above ground level). Photovoltaic or solar thermal systems are not possible due to heritage protection. Until now, I had assumed a gas boiler for the house since there is a gas connection in the street, although it has not yet been connected to the house (original heating was a central coal heating system, but unused and unoccupied for 30 years).
As a rental property, it is also interesting that the green/red political plans to impose the CO2 tax on landlords would not be problematic in this case, since electricity costs are charged directly to the tenant and therefore initially would not appear in the additional costs.
On paper, the air-to-water heat pump is clearly advantageous, but what is the reality here? In 2017, we chose gas for a new build due to the high electricity consumption. This is an old building that is allowed to have up to 60% more primary energy demand than a new build. Can the figures for the air-to-water heat pump be trusted to some extent, or will the electricity consumption be a disaster?
Thanks in advance for your opinions—I had never really considered an air-to-water heat pump before and therefore haven't looked into it much yet.
N
nordanney14 Jan 2021 14:47Daniel-Sp schrieb:
If you have the heating load and the building volume, you can at least estimate it. Try searching for Trenchplaner and Ring trench collector. Or directly enter grabenkollektor dot Wärmepumpen-verbrauchsdatenbank dot de/Energieeinsparverordnung-heizlast dot html.
The indicated values are surprisingly close to reality and the extensive calculations made by mechanical, electrical, and plumbing (MEP) engineers.
D
Daniel-Sp14 Jan 2021 15:57That is the first step...
Let's see if I understood this correctly. For the consumption calculation...
(Heating output / annual performance factor) * full operation hours * electricity price = electricity costs
9 kW / 3 (rather conservative) * 2000 (?) * 0.35 €/kWh = 2100 € heating costs. That is about 175 € / month on average.
(Heating output / annual performance factor) * full operation hours * electricity price = electricity costs
9 kW / 3 (rather conservative) * 2000 (?) * 0.35 €/kWh = 2100 € heating costs. That is about 175 € / month on average.
Forget the air pump quickly. Use gas, save a lot of money, and avoid problems.
Even with new builds, air-to-water heat pumps often cause issues due to defects or very high consumption. After a few years, repairs are needed, such as a new compressor costing around 2,000 euros.
Even with new builds, air-to-water heat pumps often cause issues due to defects or very high consumption. After a few years, repairs are needed, such as a new compressor costing around 2,000 euros.
Bookstar schrieb:
save a lot of money First of all, gas is about €20,000 (approx. $21,500) more expensive as an initial investment (more expensive insulation, no subsidies, gas connection). Operating costs are secondary.
That means "saving" refers to repairs and service life / maintenance. So the air-to-water heat pump will need about €20,000 (approx. $21,500) in maintenance/repairs over approximately 20 years.
Similar topics