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Heat exchanger muff project

PostPosted: Sat Oct 30, 2021 9:20 am
by Wood
Good morning everyone! Hope your all doing well.
I’m thinking of building a heat exchanger muff over the winter and was wondering if anyone knows of any drawings out there that I could follow. I’ve been looking at this one https://www.aircraftspruce.ca/catalog/eppages/turboheat05-15249.php from aircraft spruce but thinking it would be a fun project over the winter. Im not sure if 8 inches would be a little to long and would need to shorten it a bit. Any suggestions would be very much appreciated.

Cheers
Mark

Re: Heat exchanger muff project

PostPosted: Sat Oct 30, 2021 10:35 am
by Bryan Cotton

Re: Heat exchanger muff project

PostPosted: Sat Oct 30, 2021 11:07 am
by XenosN42
Wood wrote:Good morning everyone! Hope you're all doing well.
I’m thinking of building a heat exchanger muff over the winter and was wondering if anyone knows of any drawings out there that I could follow. I’ve been looking at this one https://www.aircraftspruce.ca/catalog/eppages/turboheat05-15249.php from aircraft spruce, but thinking it would be a fun project over the winter. I'm not sure if 8 inches would be a little too long and would need to shorten it a bit. Any suggestions would be very much appreciated.

Cheers
Mark


I have used the heat exchanger in the link and it's great. I'd recommend it unless your need to build your own is greater than your need for cabin heat.

Re: Heat exchanger muff project

PostPosted: Sat Oct 30, 2021 10:21 pm
by mike.smith
I've tried on several occasions to make my own heat muffs, with not a lot of success. I ended up using TWO of the AC Spruce ones. Each is on a different exhaust pipe, and both feed into a single scatt tube to feed the cockpit.

Not sure about a Jab 2200, but with a VW even 2 muffs only puts out minimal heat. So it works OK for outside air temps in the 50s (Fahrenheit), but anything lower and its just blowing cold air into the cockpit. I played with various restrictors and lots of other variables for 4 years. You name it, I've tried it. Too much air flow and all you get is cold air. Too little air and there is little heat that gets to the cockpit.

If you have more luck with a Jab 2200 I'm sure we'd like to hear about it, but on a VW there just isn't enough heat being produced from the engine. Think about it... how well did a VW bug do with heat in the winter!?

Re: Heat exchanger muff project

PostPosted: Sun Oct 31, 2021 8:48 am
by GraemeSmith
Straight and level - shoes off - socks on firewall. Toes stay warm.

I did look at these this year:

https://www.homedepot.com/p/Milwaukee-M ... /313562987

Re: Heat exchanger muff project

PostPosted: Sun Oct 31, 2021 9:06 am
by Wood
Bryan Cotton wrote:Be sure to read this:
viewtopic.php?f=7&t=4730

And this:
viewtopic.php?f=7&t=5366&p=40644


Hi Bryan. Thanks for this. Great info.

Mark

Re: Heat exchanger muff project

PostPosted: Sun Oct 31, 2021 9:10 am
by Wood
XenosN42 wrote:
I have used the heat exchanger in the link and it's great. I'd recommend it unless your need to build your own is greater than your need for cabin heat.


Hi Michael
Thanks for this. I was looking at this one for sure but thought it would be fun to fabricate one over the winter. It looks like I’ll just bet this one.


Mark

Re: Heat exchanger muff project

PostPosted: Sun Oct 31, 2021 9:22 am
by Wood
mike.smith wrote:I've tried on several occasions to make my own heat muffs, with not a lot of success. I ended up using TWO of the AC Spruce ones. Each is on a different exhaust pipe, and both feed into a single scatt tube to feed the cockpit.

Not sure about a Jab 2200, but with a VW even 2 muffs only puts out minimal heat. So it works OK for outside air temps in the 50s (Fahrenheit), but anything lower and its just blowing cold air into the cockpit. I played with various restrictors and lots of other variables for 4 years. You name it, I've tried it. Too much air flow and all you get is cold air. Too little air and there is little heat that gets to the cockpit.

If you have more luck with a Jab 2200 I'm sure we'd like to hear about it, but on a VW there just isn't enough heat being produced from the engine. Think about it... how well did a VW bug do with heat in the winter!?


Hi Mike. Appreciate your advice. Just to test and see if it would work i did connect a scary hose into the cabin box up to the muffler muff just to see if it would pick up a enough heat to make it worth while. What I found was a significant change in the cabin. However, because the end of the scary hose was open and close to the muffler muff I found great heat at slower speeds as and as speed increased heat decreased as the airflow washed it out. So I’m thinking if it was definitely connected to the muff or the a heat exchanger then it would work perfectly. I would be flying in temps below -10 decrees C but it will be something.
Thanks a lot

Mark

Re: Heat exchanger muff project

PostPosted: Thu Nov 04, 2021 7:38 pm
by mike.smith
Wood wrote:
Bryan Cotton wrote:Be sure to read this:
viewtopic.php?f=7&t=4730

And this:
viewtopic.php?f=7&t=5366&p=40644


Hi Bryan. Thanks for this. Great info.

Mark


Those posts are regarding a turbo AeroVee. I'm guessing there is a lot more heat to be had. I still have not seen proof of any successful heating solution off of a standard VW engine. I'm hoping someone someday will have empirical evidence and photos. Maybe if I remember I'll make a video of my installation and post it on YouTube.

Re: Heat exchanger muff project

PostPosted: Fri Nov 05, 2021 11:23 am
by WesRagle
Hi Guys,

mike.smith wrote: I still have not seen proof of any successful heating solution off of a standard VW engine. I'm hoping someone someday will have empirical evidence and photos. Maybe if I remember I'll make a video of my installation and post it on YouTube.


I love to fly on crisp wind free mornings. This morning was just such a morning.

Forecast from yesterday evening:

Image

I read Mike's post last evening and decided to take my little digital thermometer and a camera with me to the airport for my morning flight. The thermometer has been checked with the standard ice bath/boiling water test and is accurate.

Ignore the reading on this pic. The thermometer had just been pulled out of the warm truck and stuck to the panel. I had handled the probe and there was no airflow in the cockpit. The pic shows the thermometer stuck to the panel with probe dangling just below the panel.

Image

I took off right at morning civil twilight, so no solar heat in the cockpit. The KMWL WX ASOS was reporting 3 Deg. C. The field elevation is ~1000 ft. I took off and climbed to 3500 ft. and then started fumbling for the camera.

Hard to see in this pic but the oil temperature was up to 185 Deg. F. I had climbed close to 3000 ft. If you assume the standard temperature laps rate, OAT when the pics were snapped would have been about 26 Deg. F.
Image

The temperature of the air coming into the cockpit as measured just below the instrument panel was approximately 84 Deg F.
Image

It was quite comfy in the cockpit. After 15 minutes of getting me back up to temp from a cold pre-flight I actually had to turn the heat down some.

Wes