Introduction: Fireplace Fan
Materials:
- Computer fans (2), $2.99 each, Newegg.com
- Fan noise dampeners, $1.99 for a pack of two, Newegg.com
- AC adapter / power supply, input 120V AC, output 12V 500ma, Model TEAD-41-120500U, $2.99, eBay.com
- Panel-mount stereo 3/32" submini phone jack, $2.99, Radioshack.com
- Steel sheet, 26 gauge, 12"*12". You can find this near the roofing and sheathing materials at Home Depot but basically any sheet that you can cut will work.
- Dremel
- Soldering iron
- Work bench
- Drill and a drillbit slightly larger than the threaded part of the phone jack
- Ruler and pen
Step 1: Mark Fan Screw Positions
Using the dampeners as a template, mark the position of the fan screws on the steel sheet. Leave about 1/4" inch between. Drill the holes. This will give you two squares.
Step 2: Draw Circles
Find a round object such as a mug that has the same diameter as the fan blades. Use it to draw circles in the middle of the squares.
Step 3: Cut Fan Holes
Install a metal cutting disc in your Dremel tool. Cut along the circles. Do this step outside as metal dust and sparks will fly everywhere. Wear gloves and eye and ear protection! The cut edges will be sharp. Use a sanding stone to finish them and round any other sharp corners.
At this point you can also cut the metal sheet to the correct width. It only needs to be as wide as the two fans.
Step 4: Measure and Mark Bend Lines
Draw a line at the bottom of the squares, below the fan holes. Measure one fan thickness (25 mm) from the first line and draw a second line. Measure one fan height (80 mm) from the second line and draw a third line. Cut the sheet to the right height along the third line (leftmost in the picture).
Step 5: Bend Sheet 45 Degrees
Secure the sheet into a workbench at the first line and bend it to 45 degree angle.
Step 6: Bend Sheet 90 Degrees
Then at the second line and bend it to 90 degree angle.
Step 7: Attach Fans to Case
- screw
- plastic grommet
- blade shield
- case
- noise dampener
- fan
- rubber grommet
- nut
Step 8: Solder Wires
Twist the positive (red) wires from each fan together and solder them into the positive leg of the phone jack. Twist the negative (black) wires from each fan together and solder them into the negative leg of the phone jack.
Step 9: Mount Phone Jack
Drill a hole somewhere on the case to mount the phone jack. Push the jack through and secure with the nut provided. Stash the cords inside the case so they don't come into contact with the spinning fans.
Step 10: Glue Pads to Bottom of Case
Glue furniture pads to the bottom of the case to eliminate vibration and noise further.
Step 11: Test
Plug it in and test.
Step 12: Insert Into Fireplace
Position the fan near the back of the fireplace and plug it in.

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39 Comments
5 years ago
I scrap computers so I have lots of fans. What I don’t have is knowledge of volts, hz, current consumption, mA. My speakers are 12V but the current consumption amounts are all different. Can I use 3 fans together that have different current consumption numbers?
5 years ago
I used the same fans on my Majestic 36" NG fireplace in Canada (Sask) about 3 years ago as replacements for the factory originals that started to squeal at all hours when then went on. I just took out the old ones and screwed in two of these, purchased from Princess Auto for $7.99 CAD. Soldered the connections, and away it went. Its been going ever since. I believe the fans are computer heat sink fans so they can take a fair bit of heat, which is what they are designed to do.
7 years ago on Introduction
cool
8 years ago
Keep in mind that you are voiding the warranty and you may cause the fireplace safety control features to fail. This may cause an odorless carbon monoxide gas to vent into the room.
9 years ago on Introduction
And I like the tube running through the fire.
9 years ago on Introduction
Wire in the thermastateq will come on and that will keep the fans cool. Doodado
9 years ago on Introduction
Will these fans automatically run at full speed this way, or could someone hook up a dial that would allow them to run faster? I made this (or something like this) and my fans aren't moving enough air. I was curious if my fans were pulling the maximum current by default.
12 years ago on Introduction
That looks great! I'd love to be able to build something like that, unfortunately I'm not that handy. We've been looking for an efficient little fireplace for a little while now and finally came across one that looks perfect. We found it at http://www.comfortsolutionsutah.com, check their fireplaces out!
12 years ago on Step 7
craft foam will work as well
12 years ago on Introduction
I use one of those fireplace grate heat exchangers in my home as my primary heat source burning pallet wood. I got it from hastyheat.com one of the things to note is they have these die cut ceramic fiber insulators similar to the silicone gaskets used here only they can handle much higher heat, insulate the fan better and since they are die cut they have 4 little arms and a center patch that covers the fan motor protecting it from heat, I will add a pic to best describe. Something you might consider as it seems more appropriate to the application.
13 years ago on Step 12
how safe is it to use phone jack to connect the ac/dc transformer to the fan?
Reply 13 years ago on Introduction
Thats what i thought too when i used 2 12v PC fans (with 1 A running) but it actually works well. The only concern is the plastic melting and the 2 contacts making connection, hence a short circuit, due to the heat of the fire. For a safer channel, run a chute (or square tube) made of metal to the back and then have it point to where you want the heat.
13 years ago on Introduction
This is not my idea, but I thought I would throw it out there. Epoxy a thermostat to a magnet and attach to the bottom of the firebox. When it gets hot it will turn the fans on and they will stay on until the fire cools.
13 years ago on Introduction
You Can Get Fans From an Old Computer, You Can Get the Metal From an Old Computer's Casing, and You Don't have To buy a New Adapter/Wall Wart/Power Source You Likely Have Around Collecting Dust, And If you Don't You Are Likely To find someone throwing one away. ~ReCreate
15 years ago on Introduction
cool, looks very very nice.
Reply 13 years ago on Introduction
For you electricians out there, do you see any problem with putting a dimmer switch to control the outlet in the fireplace? Would that not give better fan speed control?
14 years ago on Introduction
When I first read this title of this thread it scared the crud out of me, (make your own fireplace fan = certain death by flames) but now that I see how you made it and the application....looks like a keen idea! Good job.
14 years ago on Step 12
Great tutorial, very cleanly done (unlike some builds on here) and well thought out. Im impressed as I have actually built one of these (8 fans wide) for my wood burning fireplace that was hugely innefective at warming the entire house. Airmovement is critical if you want anything more than a body magnet like most fireplaces are. Good job!
14 years ago on Step 7
clear aquarium silicone sealant lightly "painted" on the non showing sides of sheet metal also dampens noises and vibrations.
14 years ago on Step 3
A little less time consuming way is to just buy the right size hole saw from your local big box home improvement center. Make sure you clamp the metal sheet to some wood with your holes and some screws. Rotating sheet metal is dangerous