I'm currently renovating my single-family home and wondering whether I should install a heat pump. Now I've read that you also need a controlled ventilation system for that. Does that really make sense and roughly how much does such a combination cost?
A ventilation system isn't strictly necessary with a heat pump, but it makes a lot of sense under certain conditions. The key thing: heat pumps need a relatively airtight house to work efficiently. If you're sealing your house up properly during renovation anyway (new windows, better insulation), you run into the problem that natural ventilation through cracks and gaps disappears. That's where controlled ventilation comes in - it makes sure moisture and CO2 get out and fresh air gets in without you having to constantly throw windows open. It also saves heating energy because you're not wasting heat by heating with open windows.
The combination is especially worthwhile if the ventilation system has heat recovery built in. The warm exhaust air transfers its heat to the fresh outside air before it leaves - that significantly cuts down your heating needs. Without ventilation, that would be a huge waste with airtight renovation. But you can also just install the heat pump first and retrofit a system later if it turns out you need it.
On the costs: a decent ventilation system with heat recovery will run you somewhere between 3000 and 8000 euros depending on size and quality, installation included. Heat pumps are similarly expensive, but it depends a lot on the type (air, ground, water). All told you should budget 15000 to 25000 euros before you factor in subsidies - and there's quite a bit of government funding available right now that can cover a large chunk. But it pays for itself in the long run through savings on heating costs.
The combination isn't automatically necessary - a heat pump works fine without a ventilation system as long as your house isn't too airtight. It makes more sense if you're already going for high-quality windows and good insulation during renovation, because then you need the system to keep moisture and CO2 under control.
On costs, I'd roughly say: ventilation runs between 3,000 and 8,000 euros depending on the scope of work, and the heat pump itself costs significantly more. Whether the combination pays off really depends on your current situation - if you're renovating anyway and need good insulation, it fits together, otherwise the ventilation might not be worth it yet.
Heat pumps basically work fine without a separate ventilation system, but whether it makes sense for you depends on how airtight you make your house during renovation. If you're installing modern windows, better insulation, and airtight details - so really high-end renovation - then natural ventilation becomes tight and a controlled system pays for itself. With a simpler renovation where there are still a few cracks and gaps, you often don't need one.
As for costs: a good heat pump itself runs roughly between €20,000 and €40,000 including installation, and a ventilation system with heat recovery adds another €5,000 to €15,000 - but I'd see that less as extra costs and more as something to check whether it's actually necessary for your house renovation concept. Get advice from an energy consultant on this - they can look at your house and tell you whether it makes sense.
During an energy renovation, it's less about whether you *need* a heat pump, but more about how airtight your house will be in the end. That's the crucial point people often overlook: if you install modern windows, insulate the walls, and seal everything up, you're automatically closing off the uncontrolled air leaks that used to happen through gaps and cracks. That's great for heating, but then you've got to make sure fresh air gets in somehow - otherwise it gets stuffy and moisture builds up.
So the ventilation system isn't necessary because of the heat pump, but because of how airtight the house itself is. If you're already doing a thorough renovation anyway, a decentralized or centralized ventilation system often makes sense - not necessarily expensive, and you save yourself the hassle of manual ventilation down the line. Cost-wise: a decent ventilation system runs somewhere between 3,000 and 8,000 euros depending on the type and size of your house, and the heat pump itself costs about the same. Whether you really need one depends on what you're heating with now and what your insulation looks like - an energy consultant on-site can give you a better answer on that than I can here.
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