ᐅ Warm bedroom in a house with ventilation including heat recovery

Hello,

we have a central ventilation system with heat recovery. In the bedroom, the heating is turned off, yet in the evening at 10 pm, the temperature is still 21°C (70°F) while it’s 10°C (50°F) outside. All windows are, of course, closed. There is one air outlet (air supply) in the bedroom. The shutters were closed during the day, so very little solar heat entered. Still, it always gets too warm in the evening. Could this be caused by the heat recovery ventilation system, which is supplying warmer air into the room than expected? What could be done about this? Lowering the temperature of the heat recovery system doesn’t seem to make sense, as that would defeat the whole purpose of the system. Slightly opening a window helps little if the shutters are open.

How have you solved this or what else could be causing it? The heating is definitely off, and the display on the distribution box also shows it as closed.

Overnight it gets even warmer because the resting heat from two people exceeds the heat loss to the outside.

This is because your house – depending on the construction type – is like a firebrick... once heated, it retains warmth for a long time. However, this also means that it is difficult to create large temperature differences between rooms in modern houses.
We also have 21°C (70°F) in the bedroom.
I can recommend camel hair blankets – they are nice and lightweight.

Buy a waterbed, then the air will feel pleasantly cool compared to the 29°C (84°F) of the waterbed.

Joking aside, using a ventilation system won’t change that. Unfortunately, this is normal for you.

Cool air is often perceived as fresh and pleasant. However, the quality depends not on temperature but on CO2 levels and humidity. In my opinion, people tend to sleep better in modern, airtight, and well-insulated houses with ventilation systems than in older homes with windows tilted open (compare the air exchange rates) or even in new houses without controlled mechanical ventilation.

Another advantage for those who prefer to sleep in cooler conditions: in this setup, summer temperatures are likely to be lower than in traditional houses (I used to have temperatures above 30°C (86°F) in the attic at 10 p.m.).

Alternatives (which I do not recommend): a tent in the garden (not sealed tightly); fully opening windows.

In summer, it might be cooler than before, but right now in spring it’s relatively warm in the bedroom – and we just can’t get it cooler. The ventilation system annoys my wife because the draft seems to constantly irritate her eyes. We want to try covering the ventilation in the bedroom and keeping the window slightly open. Or maybe turn the ventilation down a notch at night. We’ll see. It would have been nice if there was a simple solution for this.

But actually, it shouldn’t be "normal" to experience a draft caused by air exchange or air movement, right?

Maybe there are also insights from other users of a controlled ventilation system.

Regards, Andreas