Difficulty Level (Easy, Medium, Hard, Insane):
Medium
Process:
For the last 5 or 6 years I've been using a direct heat diesel heater in my shop to heat it up in the winter. It works really well and even at -20 (celsius) it's up to a comfortable 20 degrees in about 5-10 minutes. Unfortunately, the exhaust fumes are also in the shop and after many years of breathing in those fumes I was actively on the look-out for an alternative.
I would like to mention, that I always turn on my air exchanger when the heater runs and DO have a carbon monoxide alarm that I've had in my shop to make sure I don't accidentally kill myself, but even after a full day in the shop, it usually hovers around the 25 ppm range which, according to WHO, NIOSH and OSHA are all acceptable levels.
Once, I turned the air exchanger off, turned the heater on and left it on for 8 hours while I was NOT in the shop. After a full 8 hours of no air being exchanged, the CO levels were only up to 40 ppm but the fumes smelled awful.
In any case, I got the new heater on kijiji for $100 bucks (only so cheap because it wasn't working) and spent about a day Fixing the Indirect Diesel Shop Heater MH1000ID.
Once I got it running I called the local fire department to see what the code stipulated for these types of heaters because they're temporary by nature and the exhaust flue only gets to about 100 degrees (celsius) so it's not nearly as hot as a wood stove for example. I also consulted with a plumbing/heating friend of mine (thanks again for your time, Jordan!) and was confident to implement the venting.
Typically, these heaters are used outside and bring the hot air inside with a 16" hose, but I wanted to capitalize on the efficiency and have it stationed inside. The one thing that was still bothering me though is that I've had almost 3000 cubic feet of 200 degree (celsius) hot air per hour being vented outside which seemed like such a waste of heat, so after some planning, sketching and research decided to build an additional air exchanger to try to reduce the flue temperature even more.
A friend of mine has a CNC plasma cutter and since I've done some work for him on my lathe, he didn't mind cutting up the metal parts for me. I could have used the angle grinder instead, but cutting out the round and square holes would have taken a bit of time so the accuracy and convenience of the CNC plasma cutter was much appreciated (thanks, Eric!)
After cleaning up the pieces, I used my DIY Sheet Metal Brake to bend the pieces to shape, then drilled, sealed (with fire place caulking) and riveted the pieces together. All that was left, was to cut the existing horizontal flue with my angle grinder, install the newly built heat exchanger and put some high heat paint on it.
Now, the flue gases are already down to 150 degrees (celsius) and with an additional fan I should be able to get it down to around 100 degress which means I just cut the waste by 50%. Sounds like a successful project by any measure!
Files:
DWG: Heat Exchanger.dwg
DXF: Heat Exchanger.dxf
Videos:
Pictures:
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| The heater before the heat exchanger was installed |
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| Energy savings calculations: $2/day |
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| My inspiration: Very common in Europe |
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| Some of my sketches |
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| Some more sketches |
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| The AutoCAD plans of all the parts |
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| The parts and left over from the plasma cutting |
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| The dirty metal parts |
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| The cleaned metal parts |
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| Measuring the flue gas temperature |
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| Close-up of the K-type thermocouple |
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| Running exactly 200 degrees (celsius) |
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| Putting together the cap |
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| Using fire place caulking to seal the cracks |
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| Another view |
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| Doing the channels |
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| Sealing the channels to the plate |
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| Another view |
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| My setup |
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| The rad/exchanger part done |
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| Another view |
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| Another view |
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| Test-fitting the caps |
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| Another view |
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| Another view |
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| Another view |
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| Another view |
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| The finished heat exchanger |
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| The installed heat exchanger |
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| Another view |
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| Another view |
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| Another view |
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| The painted heat exchanger |
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| Another view |
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| Another view |
Metal band saw
Angle grinder
Belt sander
Hammer
Measuring tape
Digital calipers
Marker
Square
Level
DIY sheet metal brake
Eye & ear protection
Tin snips
Needle nose pliers
Rivet gun
Indirect diesel heater
Materials:
One 4' x 8' sheet of 22 gauge sheet metal
1/8" x 1/2" rivets
Two tubes of fire place caulking
One 6" duct starting collar
High heat paint
Cost:
$50
Time:
6 hours
Savings:
Not sure, maybe $100 bucks
Conclusion:
It works great and will save me a couple bucks in fuel per day
Hello Chris,
ReplyDeleteI loved this video. My business is designing, building and selling fluid to fluid heat exchangers. You are a genius!
Best Regards Peter