Thinking about trying the heat circulating fireplace running on battery (via inverter) only to see how warm the house stays. Anyone else doing any tinkering/testing?
You might want to look at the power requirements of the fan motor(s) you will need to run. Volts (110) times the amperage draw of your motor will equal the wattage consumed. Take that wattage and divide it by 12 volts and that will be a little less than the current draw out of your battery. The inverter will have some loss because it will not be 100% efficient.
For example: a 110 volt small fan motor drawing 1 amp would consume 110 watts. On a 12V battery powered inverter it will still draw 110watts now divided by 12V which equals 9.2 amps plus a little loss, so figure about 10 Amps. A standard deep cycle marine battery might realistically give you 5-6 hours runtime before a recharge is needed.
A small generator outside with a couple long cords might be a more efficient option for your furnace fan, and you could touch up your refrigeratorand freezer a couple hours each day, run a coffee pot, microwave, and have a table light if you wanted.
Keep us updated on how you make it work.
For example: a 110 volt small fan motor drawing 1 amp would consume 110 watts. On a 12V battery powered inverter it will still draw 110watts now divided by 12V which equals 9.2 amps plus a little loss, so figure about 10 Amps. A standard deep cycle marine battery might realistically give you 5-6 hours runtime before a recharge is needed.
A small generator outside with a couple long cords might be a more efficient option for your furnace fan, and you could touch up your refrigeratorand freezer a couple hours each day, run a coffee pot, microwave, and have a table light if you wanted.
Keep us updated on how you make it work.
FYI: In my today's mail there was a Harbor Freight coupon for a 4000w peak / 3200w running generator for $290. That would give you about 30 Amps to use.
My 6500 watt unit burns about 5 gallons in about 7 hours when pretty well loaded, so this one should be about half of that.
Let us know what you work out.
My 6500 watt unit burns about 5 gallons in about 7 hours when pretty well loaded, so this one should be about half of that.
Let us know what you work out.
They only pull 110 watts at full speed. Inverter is 85% efficent so draw should be just a hair north of 9 amps to start and pick up as the voltage drops. It's running off a pair of golfcart batteries rated at 232ah in series so plenty of amp hours to test with. The only thing is that it's a modified sine wave inverter so it will setup some harmonics in the motors (ac induction motors) but they are low torque with decent windings so it won't hurt them. This is just to test a wind/solar scenario if we lost power and had no access to fuel (iced in, shtf, etc).
I did a little experiment like this once on a really cold night with the geothermal unit off and just the blower fan to circulate. With a single charge of hardwood, we brought the house from 68 to 70 (too much of my tinkering with input air and damper settings) and if I remember right, it dropped back down to 68 overnight. The house is really tight and with the concrete walls, the interior temps don't like to move very quickly. Since we keep the house at 69 when people are here and 67 when gone or sleeping in the winter the mass of the walls really works to hold the temps in place. Anyway, below is a link to the fireplace we are using. It's not quite as efficient as some of the catalyst fireplaces but since it just uses reflection and a secondary chamber, there is less to go wrong with it.
http://www.kozyheat.com/product/231zc
I'm using one of the 750 watt units for this test. Like I said above, modified sinewave but I've run a miter saw and circular saw through 2x4s with it off the truck and got it for 38 bucks on a sale+discount day. For the money, there is none better! My next one will be a pure sinewave unit.
I might have the same generator as you. I've got one of the large frame John Deere portables (9kw peak and 6.2kw rms iirc)? Anyway, it's a good unit. It will run our typical loads and the geothermal if I'm careful.
I appreciate the advice and I"ll let you guys know how it works out. Mostly the cold weather is hurting my cedar killing spree so I had to do something useful with the time.
I did a little experiment like this once on a really cold night with the geothermal unit off and just the blower fan to circulate. With a single charge of hardwood, we brought the house from 68 to 70 (too much of my tinkering with input air and damper settings) and if I remember right, it dropped back down to 68 overnight. The house is really tight and with the concrete walls, the interior temps don't like to move very quickly. Since we keep the house at 69 when people are here and 67 when gone or sleeping in the winter the mass of the walls really works to hold the temps in place. Anyway, below is a link to the fireplace we are using. It's not quite as efficient as some of the catalyst fireplaces but since it just uses reflection and a secondary chamber, there is less to go wrong with it.
http://www.kozyheat.com/product/231zc
I'm using one of the 750 watt units for this test. Like I said above, modified sinewave but I've run a miter saw and circular saw through 2x4s with it off the truck and got it for 38 bucks on a sale+discount day. For the money, there is none better! My next one will be a pure sinewave unit.
I might have the same generator as you. I've got one of the large frame John Deere portables (9kw peak and 6.2kw rms iirc)? Anyway, it's a good unit. It will run our typical loads and the geothermal if I'm careful.
I appreciate the advice and I"ll let you guys know how it works out. Mostly the cold weather is hurting my cedar killing spree so I had to do something useful with the time.
I really kind of half assed my little trial run. Ran the fans over new years night and totally forgot to check the battery voltage when I started. It ended at 12.8 so it was probably in the 13.6 range. I also forgot to test actual draw. I did run the fireplace for about 14.5 hours (5:30pm to about 8am). In that time, the house started at 67* and climbed to 69 when we finally went to bed. It was back to 67 by 8am when i finally drug myself out of bed. Since the ice turned into a big stack of nothing yesterday, I wrapped up and spent the day with my chainsaw and some cedar more cedar trees. I wanted to leave the geo off but wifey was having none of that.
Major problem is that unless I run the blower fan, the living room with shoot up in temp and be very warm but the rest of the house will get progressively colder. We've also got a vaulted ceiling in the living room which traps the heat from the fireplace so I have to run the ceiling fans to keep the air mixed. Neither of these wattages were accounted for in the test. So cots in the living room would be very comfortable for sleeping but as designed, even a tight room will get cooler unless the air is moved with a forced air scenario. I do have a sealed envolop attic (basically foam sprayed against the roof rather than blown on the attic floor. I thought about putting a vent on each side of the vault and exausting it to the attic and turning that into a plenum to let individual fans in the bedrooms some of the warm air down and into the room. What do you guys think?
Major problem is that unless I run the blower fan, the living room with shoot up in temp and be very warm but the rest of the house will get progressively colder. We've also got a vaulted ceiling in the living room which traps the heat from the fireplace so I have to run the ceiling fans to keep the air mixed. Neither of these wattages were accounted for in the test. So cots in the living room would be very comfortable for sleeping but as designed, even a tight room will get cooler unless the air is moved with a forced air scenario. I do have a sealed envolop attic (basically foam sprayed against the roof rather than blown on the attic floor. I thought about putting a vent on each side of the vault and exausting it to the attic and turning that into a plenum to let individual fans in the bedrooms some of the warm air down and into the room. What do you guys think?
As for the attic plenum to the bedrooms, I would think even a small loss through the insulation might negate much heating if your attic has a large surface area.
At my airport hangar before installing ceiling fans, I used a floor standing fan tilted upward at about 45' to "mix" the cooler air from the floor area and blowing it into the warmer toward the ceiling. That circulation worked well for an open area. I used another fan on low blowing that warmed air down the hallway toward a bed room ("L" shaped apartment in a corner,) and did not use the additional noisy heat/cool unit in that small area. We use the same fan blowing down the hall for cooling in the summer most of the time when we are spending the night.
That might be an easy temporary set up for you to consider to use off an extension cord from your generator.
At my airport hangar before installing ceiling fans, I used a floor standing fan tilted upward at about 45' to "mix" the cooler air from the floor area and blowing it into the warmer toward the ceiling. That circulation worked well for an open area. I used another fan on low blowing that warmed air down the hallway toward a bed room ("L" shaped apartment in a corner,) and did not use the additional noisy heat/cool unit in that small area. We use the same fan blowing down the hall for cooling in the summer most of the time when we are spending the night.
That might be an easy temporary set up for you to consider to use off an extension cord from your generator.
I have one of these I bought off of ebay and it's been working for about 5 years now.
https://www.stirlingengine.com/product/stirling-engine-stove-fan/
https://www.stirlingengine.com/product/stirling-engine-stove-fan/
Last edited by a moderator:
That's pretty cool! Stirling engines are neat.
Very cool! I've never seen one of those.
my woodstove is at the end of a 30 foot hallway and I have 3 bedrooms and a bathroom down there and it will push the hot air down there and keep them warm and it keeps the air moving around the house and I can leave it running 24/7 and it doesn't hurt my electric bill one bit.
