Why not look into the solid state devices that generate electricity based upon a temperature differential? Then the heat of the exhaust stack could power the blower fan?
thermoelectric coolers, or peltier devices have an efficiency of about 3%. and they cost a hundred dollars per watt of useful energy. They are very low current DC devices, meaning very little torque, and DC motors have a very limited life (5,000 hrs is a good duration). You could step up to a brushless dc motor and pay a hundred dollars for a 20,000 hr life.
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a sterling motor directly coupled to a squirrel cage blower. the sterling motor ain't cheap, but it is the only expensive component in the system; and because of it's inherent design (atmospheric pressure work chamber) they have an exceedingly long lifetime.
that's my analysis. that and I think sterling motors are cooler than an ac synchronous any day of the week.
But the sterling motor would probably be pretty loud. I've actually never seen a wood pellet stove but I'm assuming it doesn't look that much different than a wood stove. If it's in someone's living room, they're not going to want a piston in there proudly pumping away unless you only plan to sell to mechanical engineers that have no wives.
The thermoelectric solution would be silent, which is a nice advantage.
Other than perhaps having to prime the system (get out your old blacksmith's bellows) I think it could work. The better woodstoves (i.e. not the kind most cheapskates buy) use outside feed air as it is - which is going to be cold. Then you have probably 500+ degree exhaust temperature.
I wonder what the airflow requirements are. My brother-in-law's pellet stove seems to move a lot of air through the burner.
I'm thinking of getting a woodstove, since our fireplace and chimney would need to to be relined anyway to use as-is.
Sadly, I'm guessing it's more cost-effective to just brute-force it with a generator to run the existing gas furnace. (Which would also cover the fridge, some lights, some communications...)
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OR
a sterling motor directly coupled to a squirrel cage blower. the sterling motor ain't cheap, but it is the only expensive component in the system; and because of it's inherent design (atmospheric pressure work chamber) they have an exceedingly long lifetime.
that's my analysis. that and I think sterling motors are cooler than an ac synchronous any day of the week.
Reply
The thermoelectric solution would be silent, which is a nice advantage.
Reply
I wonder what the airflow requirements are. My brother-in-law's pellet stove seems to move a lot of air through the burner.
I'm thinking of getting a woodstove, since our fireplace and chimney would need to to be relined anyway to use as-is.
Sadly, I'm guessing it's more cost-effective to just brute-force it with a generator to run the existing gas furnace. (Which would also cover the fridge, some lights, some communications...)
Reply
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