ᐅ New Build – Gas Heating and Mechanical Ventilation with Heat Recovery – Without Solar?

Hello,

we are currently planning our new build (start 2018).

I have a question:

Is it sufficient to have a gas condensing boiler plus a mechanical ventilation system with heat recovery? Or is a solar system mandatory when using a gas condensing boiler?

Best regards,
fuba777

Briefly, yes, it is possible. Solar is not universally mandatory. However, a renewable energy share for heat generation is required, and this can also be achieved with a controlled ventilation system. Another alternative would be biogas, but who actually has that.

Your heating installer will probably tell you otherwise, maybe also the energy consultant (or the person preparing the thermal insulation certificate). But don’t let them mislead you—you should ask them to provide written evidence if they say otherwise.

For gas heating without solar plus controlled residential ventilation, you will need adequately well-insulated exterior walls to comply with the energy saving regulations.

Only a professional can calculate this. What is the reason against solar? It is probably more cost-effective than complicated insulation.

... a well-insulated exterior wall, or no windows on the north side, or many windows on the south side. Or...
It is all a combination of several elements and a calculation exercise for the expert.

I generally think it’s better without solar. It rarely provides much additional benefit. However, since you are building new, will have a controlled ventilation system, and good insulation, your heating load will be so low that even the smallest gas boiler will be too large. In that case, I would seriously consider a heat pump.

This is how it looks – just having a controlled residential ventilation system alone is not enough... the whole package has to be right.