ᐅ Replacing the Heating System in an Older Home – Gas or Air Source Heat Pump
Created on: 27 Sep 2020 07:37
J
Jule_Neu
Dear forum members,
We recently purchased a house and have been in contact with our heating contractor for some time, considering how to upgrade the heating system. The house is an end-of-terrace with a split-level design – meaning the floors are mostly open to each other. Currently, there is a relatively new gas condensing boiler installed, about 4 years old. The problem is that all radiators are connected to a one-pipe system, which is very inefficient and also incompatible with future heating systems. This was the main reason we started thinking seriously about the heating system. Otherwise, we would have just replaced a few radiators.
After many discussions and considerations, we have at least decided that we want to switch to underfloor heating. The rooms are quite small, the radiators significantly interfere with the interior design, and we have a small child who usually spends half the day on the floor. Since the whole house needs renovation anyway (floors, walls, bathrooms), we will be removing everything regardless. Installing the underfloor heating would not cause much additional effort.
Our heating contractor suggested underfloor heating combined with an air-source heat pump, partly because there are currently good subsidy options for this. At first, we really liked the idea, but doubts are beginning to arise. Our house is exactly 3 meters (10 feet) from the neighbor’s boundary, and the air-source heat pump would have to be installed within this 3-meter (10 feet) space. We definitely want to avoid any trouble with the neighbors, and we are also unsure if we would get annoyed by the humming noise from the air-source heat pump eventually, since our kitchen window/dining area would be directly above the unit.
So we are now wondering if it is really necessary to replace the existing condensing boiler. Could we not run the underfloor heating using this existing system? Of course, we would lose the subsidy, but this seems more reasonable to us right now. Or are we mistaken and do gas costs then skyrocket when operating an underfloor heating system?
Another point that bothers us is the relatively high electricity costs of the air-source heat pump. By our calculations, the electricity costs would be roughly the same as the gas consumption with the current gas heating system (the house is still rented, so we know the consumption). Aside from the ecological aspect, we can’t see any advantage for us.
We would really appreciate your feedback, as we need to make a decision soon.
We recently purchased a house and have been in contact with our heating contractor for some time, considering how to upgrade the heating system. The house is an end-of-terrace with a split-level design – meaning the floors are mostly open to each other. Currently, there is a relatively new gas condensing boiler installed, about 4 years old. The problem is that all radiators are connected to a one-pipe system, which is very inefficient and also incompatible with future heating systems. This was the main reason we started thinking seriously about the heating system. Otherwise, we would have just replaced a few radiators.
After many discussions and considerations, we have at least decided that we want to switch to underfloor heating. The rooms are quite small, the radiators significantly interfere with the interior design, and we have a small child who usually spends half the day on the floor. Since the whole house needs renovation anyway (floors, walls, bathrooms), we will be removing everything regardless. Installing the underfloor heating would not cause much additional effort.
Our heating contractor suggested underfloor heating combined with an air-source heat pump, partly because there are currently good subsidy options for this. At first, we really liked the idea, but doubts are beginning to arise. Our house is exactly 3 meters (10 feet) from the neighbor’s boundary, and the air-source heat pump would have to be installed within this 3-meter (10 feet) space. We definitely want to avoid any trouble with the neighbors, and we are also unsure if we would get annoyed by the humming noise from the air-source heat pump eventually, since our kitchen window/dining area would be directly above the unit.
So we are now wondering if it is really necessary to replace the existing condensing boiler. Could we not run the underfloor heating using this existing system? Of course, we would lose the subsidy, but this seems more reasonable to us right now. Or are we mistaken and do gas costs then skyrocket when operating an underfloor heating system?
Another point that bothers us is the relatively high electricity costs of the air-source heat pump. By our calculations, the electricity costs would be roughly the same as the gas consumption with the current gas heating system (the house is still rented, so we know the consumption). Aside from the ecological aspect, we can’t see any advantage for us.
We would really appreciate your feedback, as we need to make a decision soon.
nordanney schrieb:
????
What noise? From the heat pump? That’s just a rumor. There are isolated cases – just like there are isolated cases where indoor units make noise (even a gas boiler makes some sounds).As I said, I’ve only been looking into this topic for a few days. Before, I wouldn’t have thought that underfloor heating combined with an air-to-water heat pump makes sense in an older building. I just did some casual research online and came across the limit values.
N
nordanney27 Sep 2020 10:09I would keep the gas boiler as well. Not because the heat pump wouldn’t make sense (the house is insulated except for the façade insulation), but because I don’t want to replace a nearly new gas heating system for cost reasons.
nordanney schrieb:
I would also keep the gas boiler. Not because the heat pump doesn’t make sense (the house is insulated except for the facade insulation), but because I don’t want to replace a nearly new gas heating system for cost reasons. It might be worthwhile in this particular case due to subsidies. So it can be a factor, but doesn’t have to be.
In this case, I would still keep it and design the underfloor heating system to require the lowest possible supply temperature, based on a room-by-room heating load calculation.
That way, it’s possible to switch to a heat pump later if desired. But it’s not mandatory.
So if a heating engineer makes me such a proposal, I would expect them to be able to calculate precisely whether it is actually worth it for me.
Otherwise, I would get a quote from a second heating technician and ask for their recommendation.
The gas boiler is really practically new, and personally, it would pain me to dispose of it or sell it for little money.
Otherwise, I would get a quote from a second heating technician and ask for their recommendation.
The gas boiler is really practically new, and personally, it would pain me to dispose of it or sell it for little money.
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