ᐅ Planned ventilation concept using the chimney to utilize excess heat

Has anyone already developed a ventilation concept for a house with a fireplace to make use of the excess heat? Especially in new buildings with underfloor heating, the fireplace often produces much more heat than needed. Have you ever implemented a system to use this heat for the basement or garage by directing the surplus warmth from the living room there?

Why do you ask this as a heating engineer?
Why would anyone direct surplus heat into an unheated basement or garage?
Heating ventilation concepts are better suited for living spaces, right? For example, with heat recovery.

ypg schrieb:

Why do you ask that as a heating engineer?
Why would you direct excess heat into the unheated basement or garage?
Heating ventilation concepts are better suited for living areas, right? For example, with heat recovery.

Of course, we are installing a ventilation system with heat recovery!
However, that doesn’t change the fact that as soon as we use the fireplace because the fire just feels nice, the living room quickly heats up to over 28 to 30°C (82 to 86°F), and the rest of the house maintains a normal room temperature.
The garage and workshop basement can definitely absorb some heat—for example, when I can continue working on my classic car.
In this case, it makes sense to channel warm air from above the fireplace ceiling into the garage or basement, while bringing cooler air back into the living room.
I understand that this is somewhat of a luxury, but it still makes sense.

SPATZ242 schrieb:

It definitely makes sense here to vent warm air from the ceiling above the fireplace and direct it into the garage or basement, while supplying cooler air to the living room.

Since warm air contains more moisture, you could create a mold problem in the cool basement with 100% humidity, whereas the living room air might dry out. Not to mention the dust and dirt issues in warm air ducts. In short, I wouldn’t do it.

SPATZ242 schrieb:

Of course, we are installing a ventilation system with heat recovery!
However, that doesn’t change the fact that as soon as we use the fireplace because the fire simply looks nice, the living room temperature quickly rises above 28 to 30 degrees Celsius (82 to 86°F), while the rest of the house remains at normal room temperature.
The garage and workshop basement can still absorb some heat, for example, when I get to work on the vintage car again.
In this case, it makes sense to duct the warm air from the ceiling above the fireplace into the garage or basement and supply cooler air to the living room.
I realize this is somewhat of a luxury, but it still makes sense.

But then you have the heat exactly when you don’t really need it. When do you usually operate the fireplace? Probably in the evening. And after that, you likely don’t work on the vintage car anymore. By the next morning, the heat will probably have dissipated.
Don’t overheat the fireplace; this way, you’ll have a comfortable 25 degrees Celsius (77°F) in the house during the evening. And put a small additional heater in the workshop.

It makes sense to build the chimney quite thick using fireclay bricks or something similar, so that the heat is stored and released slowly into the room.

By the way, if it’s just about the appearance, then an ethanol fireplace or even an 80-inch OLED would do.

My ex-brother-in-law had something like that in his granny flat (he connected a warm air duct from the main apartment’s chimney). The walls there were always covered in soot...