Hello. I'm new to solar and working to become self sufficient. I have a woodburning fireplace that requires ac power for the fan. I am hoping to find a way to run the fan when the power goes out. I'm sure solar is the solution but have no idea where to begin. The fan on high uses around 130 watts of 120 volt a.c. power. any suggestions? Thank you so much for your help.
How to power wood fireplace when power is out
- Thread starter AOakley
- Start date
You will need a battery and in inverter. The inverter converts the DC from the battery to AC for your fan. A 500watt 12volt inverter and a deep cycle 12v battery would be a solution. You will need to get a charger to keep the battery charged.
Have you ran the fireplace without the fan? Is that an option?
Have you ran the fireplace without the fan? Is that an option?
John Frum
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There is also heat powered fan
jasonhc73
Cat herder, and dog toy tosser.
Research Peltier cooler!
The fan is built into the unit and there is very little heat generated from this unit without the fan. The fan draws ambient air in super heats it around the firebox and then blows warm air out into the room. This unit does not work like a woodstove or woodstove insert. Soooo, without the fan, no warm room.
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Deleted member 783
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Is the fan thermostatically controlled? If so, you'll need to put a killawatt meter on it to determine the actual draw throughout a day. On a lot of those type of fireplace, the fans runs continuously, so that makes the math easier.
D
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Those things really work! Unfortunately you need a very hot surface to set it on, which he doesn't appear to have.
An AC fan (or motor) doesn't always run off AC ala Tesla's induction motor, even though it may be powered from an AC supply. If your fan (motor) has commutators with associated brushes then it is very likely a DC motor with the AC supply being rectified first to power it. In this case, you can simply power it straight from a battery. If it is a true induction motor, then, yes, you'll need an inverter as @DThames says.
Yes, the fan kicks on automatically at a certain temp and stays on until the unit cools off. Thank you
D
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Ok, so it might use a lot fewer watts than you think. A killawatt is a good, cheap investment and would give you a starting point. This is the one I use:
Thank you Lost in the Desert.. The fan is hard wired, time to call my electrician.
FilterGuy
Solar Engineering Consultant - EG4 and Consumers
@AOakley When I first read your post I assumed the system could be rather small. However when I ran the numbers, it came out larger than I expected. Is the 120 watt what is on the product label or did you measure it? Typically the name-plate rating is a lot more than is actually used.
Lets make some assumptions:
Since this is for keeping your toes warm, I assume you want this to be able to run indefinitely without grid power. Consequently you will need to generate a bit more than that each day from solar. Lets assume 1200 W/hr per day. (Enough to charge your battery bank and run the equipment)
Now lets assume you can get up to 4 days with no solar power due to clouds. (unless the panels are under snow, you will always get some power from the cells, but assuming none is conservative.) This means you battery bank needs to be rather large. (3.6K+ Whrs)
Before I go farther, are my assumptions good? Changes in any of them could change the system sizing significantly. (Particularly my assumption about how long the fan runs. )
Lets make some assumptions:
- The actual watts used by the fan is 90
- The fan runs 10 hrs/ day
Since this is for keeping your toes warm, I assume you want this to be able to run indefinitely without grid power. Consequently you will need to generate a bit more than that each day from solar. Lets assume 1200 W/hr per day. (Enough to charge your battery bank and run the equipment)
Now lets assume you can get up to 4 days with no solar power due to clouds. (unless the panels are under snow, you will always get some power from the cells, but assuming none is conservative.) This means you battery bank needs to be rather large. (3.6K+ Whrs)
Before I go farther, are my assumptions good? Changes in any of them could change the system sizing significantly. (Particularly my assumption about how long the fan runs. )
@FilterGuy The specs for the unit say that when the fan is on high it uses 130 watts. The fan is adjustable however. and can be run at a lower speed. Also, this unit is so efficient in its heating capability, I imagine even in the winter, getting a good fire going, heating the space up and then letting the fire die back down. I think a max of 8-12 hours a day would have us comfortable.
FilterGuy
Solar Engineering Consultant - EG4 and Consumers
Is that 8-12 hours of the fan running, or 8-12 hours of the burner going. (I am trying to get a handle on the number of hours the thermostat will be on and the fan is running.)
OK, that is good news. The actual draw of the fan will be something less that 130W. My 90W guess may not be too far off.
I am going to guess there is a high-med-low switch. What speed would you be using when you are on battery?
How is the fan connected? To a normal mains outlet? If so, you could buy one of those power meters and measure consumption over a typical day, for example. They are quite useful to have in your 'man drawer' for a variety of different purposes.
D
Deleted member 783
Guest
All of this has already been covered in this post.
While this is a solar forum, to be honest I would just grab a small reliable gas generator. Simpler, much cheaper and more versatile. (Unless the op is looking to power the fan perpetually vs occasionally)
ENKEEO 2300W Generator Portable Inverter, Fuel Power Inverter Generators SC2300i Gas Petrol Powered Power Supply 120V 30A Output, Super Quiet Parallel Ready for Camping Travel https://www.amazon.com/dp/B07WGSTDLW/ref=cm_sw_r_other_apa_i_XNhgEbVXQF9RF
ENKEEO 2300W Generator Portable Inverter, Fuel Power Inverter Generators SC2300i Gas Petrol Powered Power Supply 120V 30A Output, Super Quiet Parallel Ready for Camping Travel https://www.amazon.com/dp/B07WGSTDLW/ref=cm_sw_r_other_apa_i_XNhgEbVXQF9RF
Delmar
Solar Addict
If you are going to create a battery backup system, might as well go 2000+ watts and power other critical items in the house. Effort will be the same and won't be that much more expensive. Can back-feed your breaker panel.
Otherwise if you really want to power just one fan, where is the firebox air inlet? Add external 12V computer case fan(s) that will run much longer vs an inverter with 120V fan. Won't be pretty but is temporary and beats freezing to death. Here is my steampunk office circulation fan and it moves a surprising amount of air:
Otherwise if you really want to power just one fan, where is the firebox air inlet? Add external 12V computer case fan(s) that will run much longer vs an inverter with 120V fan. Won't be pretty but is temporary and beats freezing to death. Here is my steampunk office circulation fan and it moves a surprising amount of air:
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RandyB
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I have a coal stove fireplace with a blower on it. It consumes .5 amps @ 120 volts or 60 watts.
This converts to 5 amps @ 12 volts using an inverter. So for every hour of use you would need 5 amps of battery or 60 watts.
In my situation I am consuming 1440 watts per day (24 hour period) with the blower on high.
On an overcast day my 1000 watt solar set up will just barely top off my battery set up from blower use.
Remember while charging my batteries the blower is still running consuming 60 watts every hour if set to high.
On a foot note I only run the blower on medium for most the time. So normally I consume around 25 to 30 watts of power each hour.
So if you're doing solely for backup your mileage and cost may vary.
This converts to 5 amps @ 12 volts using an inverter. So for every hour of use you would need 5 amps of battery or 60 watts.
In my situation I am consuming 1440 watts per day (24 hour period) with the blower on high.
On an overcast day my 1000 watt solar set up will just barely top off my battery set up from blower use.
Remember while charging my batteries the blower is still running consuming 60 watts every hour if set to high.
On a foot note I only run the blower on medium for most the time. So normally I consume around 25 to 30 watts of power each hour.
So if you're doing solely for backup your mileage and cost may vary.
But ... I can only find 150c peltier, not 450c !!!
Perhaps theirs is 150C too
Perhaps theirs is 150C too
Devil Watt - Devil Watt 30 Watt Wood Burning Stove Thermoelectric Generator - DW-ST-30W
The DW-ST-30W Wood Burning Stove Thermoelectric Generator can be placed on the top of a wood stove to generate electricity to charge a battery, power a 12V DC device, or charge a cell phone via USB.
www.devilwatt.com
JeepHammer
Solar Wizard
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Disclaimer:
I can't recommend this since I don't have the electrical schematic and engineering design of the insert,
So purely from a discussion standpoint, and not recommending anyone take any action at all...
If it were mine I'd check to see if the air vents at the bottom were the heat intake or the fire box inlet,
And check to see if the top air vents where warm air discharge.
If this is the case, I might set a row of ultra cheep, low consumption DC computer fans to either push air into the intake, the least efficient way to force air,
Or if the front of the unit stayed cool enough I might see about drawing warm air out of the upper vents.
Since the computer fans routinely come in 12 volts, and low enough consumption they would run for several hours off a 12 volt automotive style battery, with no inverter losses, everything commonly available, I would look into it.
Since this is an urgent or emergency situation depending on outside temps, (Grid Down) I might even consider extension cord type cable from vehicle battery to fans.
Fans are so low consumption a 14 Ga extension cord would do the job well with no worry from me,
And a running vehicle next to the house (outside) isn't ideal, but it beats freezing, and let's not forget thing in the home that can freeze...
Now, if you go the DIY route, and fix the issue before it becomes urgent/emergency...
Behind the facing for the fireplace will be an electric hook up for the fan.
I would install a plug in box if it didn't already have one so the fan plug can simply be moved to a back up power source, like small solar or standby battery/auxiliary power unit.
APU's come in all shapes, sizes, capabilities. From computer backups to industrial sized units.
Solar panels on garage or where ever, batteries & inverter on a wheeled cart.
Simply unplug from panels and take it in the house for use.
It will weigh as much as two large batteries, plus inverter or what ever else the maker hangs on it,
Or since I'm the DIY type, build it myself, nothing but panels, charger (charge controller) and batteries.
I got enough of gasoline & diesel generators real fast...
First, they SCREAM, or they are too small.
(Small might work for only the blower motor and a light or two)
Fuel goes bad and takes carb gaskets and fuel pump with it.
It didn't take me too long to convert to propane which never goes bad and doesn't rot the fuel system on the genset.
Propane is as portable as gasoline, never goes bad, contained in the tank until you open the valve, and most of us have propane powered hardware now, gas grills, etc so there is already tanks laying around.
That's just what I might do, not trying to tell anyone to do it in any way...
I can't recommend this since I don't have the electrical schematic and engineering design of the insert,
So purely from a discussion standpoint, and not recommending anyone take any action at all...
If it were mine I'd check to see if the air vents at the bottom were the heat intake or the fire box inlet,
And check to see if the top air vents where warm air discharge.
If this is the case, I might set a row of ultra cheep, low consumption DC computer fans to either push air into the intake, the least efficient way to force air,
Or if the front of the unit stayed cool enough I might see about drawing warm air out of the upper vents.
Since the computer fans routinely come in 12 volts, and low enough consumption they would run for several hours off a 12 volt automotive style battery, with no inverter losses, everything commonly available, I would look into it.
Since this is an urgent or emergency situation depending on outside temps, (Grid Down) I might even consider extension cord type cable from vehicle battery to fans.
Fans are so low consumption a 14 Ga extension cord would do the job well with no worry from me,
And a running vehicle next to the house (outside) isn't ideal, but it beats freezing, and let's not forget thing in the home that can freeze...
Now, if you go the DIY route, and fix the issue before it becomes urgent/emergency...
Behind the facing for the fireplace will be an electric hook up for the fan.
I would install a plug in box if it didn't already have one so the fan plug can simply be moved to a back up power source, like small solar or standby battery/auxiliary power unit.
APU's come in all shapes, sizes, capabilities. From computer backups to industrial sized units.
Solar panels on garage or where ever, batteries & inverter on a wheeled cart.
Simply unplug from panels and take it in the house for use.
It will weigh as much as two large batteries, plus inverter or what ever else the maker hangs on it,
Or since I'm the DIY type, build it myself, nothing but panels, charger (charge controller) and batteries.
I got enough of gasoline & diesel generators real fast...
First, they SCREAM, or they are too small.
(Small might work for only the blower motor and a light or two)
Fuel goes bad and takes carb gaskets and fuel pump with it.
It didn't take me too long to convert to propane which never goes bad and doesn't rot the fuel system on the genset.
Propane is as portable as gasoline, never goes bad, contained in the tank until you open the valve, and most of us have propane powered hardware now, gas grills, etc so there is already tanks laying around.
That's just what I might do, not trying to tell anyone to do it in any way...
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