So someone better than me at maths could probably figure out how many cats I’d need to heat my with them room (and if the catfood etc needed would be cheaper than heating) …
I can answer the second question:
Generally, hot-blooded mammals transform 90% of the energy they get from food into heat.
So using a cat for heating your room is about 90% as effective as burning cat food in an oven.
Here’s some napkin math for where I live:
1kg of firewood has 4kWh = 4000 kcal
which is about equivalent to 1kg of really cheap dry cat food (mostly carbohydrates)
1kg of firewood costs about 40 cents
1kg of cheap dry cat food costs about 1,20€
So, cat-based heating is about 3.3x more expensive than burning pre-dried, commercially purchased firewood.
(all of these prices heavily depend on how much you buy in bulk, though. And if you care about your cat’s well-being, you’re gonna spend 2x more on its food)
That’s why I wrote it’s 3.3x more expensive, not 3x
10% of the energy is wasted on things like bodily functions, growing, running around and bringing joy to people.
But all that running around and buzzing and living becomes low grade heat pretty rapidly
While most of the heat from the cat food furnace will go up the chimney rather than into the room.
I would expect the cat to be closer to 100% efficient than the furnace, unless it spends its time sitting on a window sill behind the curtain radiating towards infinity
So someone better than me at maths could probably figure out how many cats I’d need to heat my with them room (and if the catfood etc needed would be cheaper than heating) …
I can answer the second question:
Generally, hot-blooded mammals transform 90% of the energy they get from food into heat.
So using a cat for heating your room is about 90% as effective as burning cat food in an oven.
Here’s some napkin math for where I live:
1kg of firewood has 4kWh = 4000 kcal
which is about equivalent to 1kg of really cheap dry cat food (mostly carbohydrates)
1kg of firewood costs about 40 cents
1kg of cheap dry cat food costs about 1,20€
So, cat-based heating is about 3.3x more expensive than burning pre-dried, commercially purchased firewood.
(all of these prices heavily depend on how much you buy in bulk, though. And if you care about your cat’s well-being, you’re gonna spend 2x more on its food)
c/theydidthemath?
But cat based heating has a lower efficiency, they do not turn all energy into heat.
That’s why I wrote it’s 3.3x more expensive, not 3x
10% of the energy is wasted on things like bodily functions, growing, running around and bringing joy to people.
But all that running around and buzzing and living becomes low grade heat pretty rapidly
While most of the heat from the cat food furnace will go up the chimney rather than into the room.
I would expect the cat to be closer to 100% efficient than the furnace, unless it spends its time sitting on a window sill behind the curtain radiating towards infinity
You sure it’s only 10%? I would have estimated about 90%
No, 90% is just for heat.