Alternative garage/shed heating using a hypocaust system
Discussion
I’ve often thought about alternative ways to heat a garage or shed for occasional use, inspired by the Roman hypocaust system — an ancient method where hot air was circulated through hollow spaces beneath the floor.
Modern electric or gas heaters tend to warm the air unevenly and rises to the roof, often leaving cold pockets.
So I’ve wondered: why not replicate the hypocaust principle using breeze blocks laid on their sides, with the hollow cores forming air channels? By placing a heater at one end and directing warm air through these channels, the blocks themselves could absorb and radiate heat, creating a more even and efficient floor-warming effect.
Not getting into deep the complexity of engineering is this worry considering or more hassle than it’s worth?
Modern electric or gas heaters tend to warm the air unevenly and rises to the roof, often leaving cold pockets.
So I’ve wondered: why not replicate the hypocaust principle using breeze blocks laid on their sides, with the hollow cores forming air channels? By placing a heater at one end and directing warm air through these channels, the blocks themselves could absorb and radiate heat, creating a more even and efficient floor-warming effect.
Not getting into deep the complexity of engineering is this worry considering or more hassle than it’s worth?
I think the issue would be that there's so much thermal mass and also the blocks wouldn't be insulated from the cold ground underneath so it would take an age and lots of wasted energy to heat up. Hypocausts were pretty inefficient unless you have a lot of unpaid labour.
Interestingly, people use a technique like this to pre-cool air being drawn into the bottom of passive solar houses, which probably should tell you something.
Interestingly, people use a technique like this to pre-cool air being drawn into the bottom of passive solar houses, which probably should tell you something.
I don't think it's worth grief.
My garage build had a standard concrete base, then oak frame construction - the walls and ceiling of the garage area have been fully insulated.
On one wall I have a frost-watch type heater that kicks in if the temperature drops below N, but it very rarely does - the temperature in there remains pretty stable and I've never seen any condensation etc.
My garage build had a standard concrete base, then oak frame construction - the walls and ceiling of the garage area have been fully insulated.
On one wall I have a frost-watch type heater that kicks in if the temperature drops below N, but it very rarely does - the temperature in there remains pretty stable and I've never seen any condensation etc.
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