hbn7hj
Senior Member
The Velit furnace has remained functional for four weeks at approximately 10,000ft.
That was my criteria for furnace success. It was achieved by running the furnace on power level five and manually turning it on and off.
Previous efforts running it in Temp or thermostat mode ended with a heat exchanger full of carbon and a non functioning furnace.
Using a TPI 710 carbon monoxide detector we get 200ppm CO at the power level five setting. Below power level four the CO level increases.
Velit claims a CO level of 20 at that setting. Another Velit furnace got 160 ppm at 10,000ft but that is the best we were able to do.
Anyhow, it works and my propane furnace has remained off.
I have disassembled the furnace twice in these experiments. In both cases the burner was carbon free but the heat exchanger had heavy carbon deposits. They do know how to design a high altitude burner. It is not clear to me how it is done though I suspect it is due to air turbulence within the burner. At the end of this season I’ll take it apart again and check the carbon deposits in the heat exchanger after only running it on power levels 4 and 5.
Vent outlet temperature is in the range of 200F so it won’t take long to heat up a van. I’m using it in a class C so it runs longer. With a thermostat mode hysteresis of +/- 3F manual operation is not an inconvenience. In summer operation at altitude you turn it on once in the morning to heat things up.
That is the latest for now. It works if you operate it correctly.
That was my criteria for furnace success. It was achieved by running the furnace on power level five and manually turning it on and off.
Previous efforts running it in Temp or thermostat mode ended with a heat exchanger full of carbon and a non functioning furnace.
Using a TPI 710 carbon monoxide detector we get 200ppm CO at the power level five setting. Below power level four the CO level increases.
Velit claims a CO level of 20 at that setting. Another Velit furnace got 160 ppm at 10,000ft but that is the best we were able to do.
Anyhow, it works and my propane furnace has remained off.
I have disassembled the furnace twice in these experiments. In both cases the burner was carbon free but the heat exchanger had heavy carbon deposits. They do know how to design a high altitude burner. It is not clear to me how it is done though I suspect it is due to air turbulence within the burner. At the end of this season I’ll take it apart again and check the carbon deposits in the heat exchanger after only running it on power levels 4 and 5.
Vent outlet temperature is in the range of 200F so it won’t take long to heat up a van. I’m using it in a class C so it runs longer. With a thermostat mode hysteresis of +/- 3F manual operation is not an inconvenience. In summer operation at altitude you turn it on once in the morning to heat things up.
That is the latest for now. It works if you operate it correctly.
