ᐅ East-west orientation of the roof surfaces, gas or air-source heat pump

Hello forum community,

We are currently facing the following issue:

We are planning to build our own home (solid construction, 140 m² (1,507 ft²)) on our property, where—as the title indicates—the ridge is oriented so that the roof surfaces face east and west. We are considering the right choice for the heating system. A natural gas line is located at the property boundary. The primary energy demand cannot yet be specified. We are a family of three and are expecting to grow :-)

District heating, oil, and geothermal energy are not options for us. Pellet heating is also excluded due to limited space. Basically, only two heating systems are under consideration: gas boiler + solar, or an air-to-water heat pump.

Now my question is: under which conditions and according to which criteria should I choose one of these two systems?

I understand that without specific data or figures no decision can be made. Still, I hope your contributions will help me decide or at least help me focus on important factors, and so on...

Best regards

Hello,

Vit84 schrieb:
...Basically, only two heating systems are available: gas boiler plus solar or air-to-water heat pump.

Since a preliminary narrowing has already been made here, the outcome also depends on the data from a basic assessment.

Vit84 schrieb:
...I am aware that without specific data/numbers no decision can be made. Nevertheless, your contributions should help me decide or pay more attention to certain aspects, etc....

Are you aware of the contradiction in your own statements?

Best regards

By the way, Taler: If you have nothing to contribute to the topic, it’s better to leave such posts out. But that’s how you can reach over 1,000 posts. Congratulations on that!

Keep in mind that solar thermal systems don’t only get heat from direct sunlight; the panels can also extract heat from the air on cloudy days or without direct radiation. Although they don’t produce as much heat as when the sun is shining strongly, they never drop to zero like solar electric systems do when there’s no sun.

Are you planning to use solar energy just for hot water or also to support heating? Are the roof surfaces free from east at sunrise to west at sunset, or are there buildings, trees, or other obstacles that limit the available time for sunlight?

Personally, I would choose an air-to-water heat pump combined with solar panels. I’m not a fan of gas, and the gas price will likely remain higher than electricity costs over the whole annual energy demand, partly due to political reasons.

There’s no objection to installing solar panels, for example, two panels each on the east and west sides. However, I’m not familiar with the local conditions, so I would meet with the heating installer on-site to review the sun positions throughout the year.

By the way, heat pumps usually have a longer service life than gas boilers and don’t involve such high maintenance costs (modern units are not something you can just recalibrate in two minutes).

Mörtelkännchen schrieb:
...Personally, I would choose an air-to-water heat pump and combine it with solar...

I wouldn’t, unless it involves photovoltaic (solar electric) systems ;-) Additionally, a standard air-source heat pump is not suitable for every application!

Best regards

Mörtelkännchen schrieb:

Personally, I would choose an air-to-water heat pump and combine it with solar. I'm not a fan of gas, and gas prices will always be higher than electricity costs (considering the annual energy demand), mainly for political reasons.

Heat pump and solar thermal system? Often doesn’t make much sense. When it’s warm outside and the heat pump is really efficient, the solar thermal system delivers the most. I’m also not so sure about the gas and electricity costs. 😉 At the moment, an air-source heat pump is only cheaper in terms of running costs if the annual performance factor is well above 3. And in real applications, that can already be quite challenging. See also the many threads in various forums about air-source heat pump consumption.