Cabin preheat ideas

This forum has been developed to discuss aviation related topics.

Moderators: lilfssister, North Shore, ahramin, sky's the limit, sepia, Sulako, I WAS Birddog

Post Reply
I_Drive_Planes
Rank 5
Rank 5
Posts: 357
Joined: Fri Jan 14, 2005 12:18 am
Location: Prince George

Cabin preheat ideas

Post by I_Drive_Planes »

I was preheating my airplane last night (an hour of work just to drive the airplane from one side of the airport to the other, what a pain!) using my Tundra Toaster (similar to a Red Dragon) heater. I thought it might be a good idea to throw some heat in the cabin so it would be a little easier on the gyros and radios so I ran the hose through the storm window. What I didn't account for was the amount of moisture that the heater throws. All the windows in the airplane immediately fogged up (hard, condensation running down the inside then freezing). I let the heater run for about 10 minutes hoping the heat would overcome the condensation, but to no avail. Maybe if I were to leave it run for longer then it would work, but I can't imagine that throwing that much moisture into the cabin would be good for the electrics (or anything else for that matter) and I'm concerned about losing too much heat from the engine while I heat the cabin.

I have no power at my tie-down so I'm looking for some ideas for preheating the cabin that don't involve 110VAC power.
---------- ADS -----------
  

ahramin
Rank Moderator
Rank Moderator
Posts: 5907
Joined: Tue Feb 17, 2004 5:21 pm
Location: Vancouver

Re: Cabin preheat ideas

Post by ahramin »

Funny, today's the day I started thinking about the same problem. In my case the best I've come up with is to plug my longest extention cord into the nearest building and push the plane to the end of the cord. It's a plan anyway ...

What kind of heater are you using? Sounds like you need something that will heat ambient air with the combustion air, rather than use combustion air directly. Or perhaps, wasteful as it is, get a small generator to run a pair of electric heaters. Your wife doesn't seem like the shrinking violet type to me but I've found any passenger is much more likely to come along if it doesn't include freezing and chattering for the first 15 minutes.

In any case, until you find a way to pump DRY warm air into the cabin, I would stick with engine preheat only for now.
---------- ADS -----------
  

Jungle Jim
Rank 6
Rank 6
Posts: 434
Joined: Wed May 26, 2004 6:29 pm

Re: Cabin preheat ideas

Post by Jungle Jim »

Guys,

I use an 1800 watt hair dryer to preheat my Thorp T18. I close up all the openings in the cowl, put the hair dryer to blow on the oil sump. In 30 minutes the CHT goes up from ambient 23-24 degrees F. After about 1/2 hour I pull the cabin heat half way and the hot air goes through the heat overflow into the cabin. I preheat about 45 minutes.

My plane is in an unheated hangar.

Jim
---------- ADS -----------
  

flyinhigh
Rank 10
Rank 10
Posts: 2559
Joined: Mon Apr 19, 2004 7:42 pm
Location: my couch

Re: Cabin preheat ideas

Post by flyinhigh »

Jungle Jim wrote:Guys,

I use an 1800 watt hair dryer to preheat my Thorp T18. I close up all the openings in the cowl, put the hair dryer to blow on the oil sump. In 30 minutes the CHT goes up from ambient 23-24 degrees F. After about 1/2 hour I pull the cabin heat half way and the hot air goes through the heat overflow into the cabin. I preheat about 45 minutes.

My plane is in an unheated hangar.

Jim
I believe that they are talking about a cabin preheat only, not engine preheat.

I have done the exact scenario that you mention with putting the heater into the aircraft. In our case we put in nozzle through the main cabin door, opened the storm window and let her go. After about 30 min there was no condensation, and the plane was hot. Almost like having an APU:)
---------- ADS -----------
  

ahramin
Rank Moderator
Rank Moderator
Posts: 5907
Joined: Tue Feb 17, 2004 5:21 pm
Location: Vancouver

Re: Cabin preheat ideas

Post by ahramin »

Your T18 takes it's cabin heat from the engine compartment? Sounds scary.
---------- ADS -----------
  

I_Drive_Planes
Rank 5
Rank 5
Posts: 357
Joined: Fri Jan 14, 2005 12:18 am
Location: Prince George

Re: Cabin preheat ideas

Post by I_Drive_Planes »

ahramin wrote:Funny, today's the day I started thinking about the same problem. In my case the best I've come up with is to plug my longest extention cord into the nearest building and push the plane to the end of the cord. It's a plan anyway ...
I like this idea, the local flight school may not like it when I unplug their plane to plug mine in though :D
ahramin wrote: What kind of heater are you using? Sounds like you need something that will heat ambient air with the combustion air, rather than use combustion air directly. Or perhaps, wasteful as it is, get a small generator to run a pair of electric heaters. Your wife doesn't seem like the shrinking violet type to me but I've found any passenger is much more likely to come along if it doesn't include freezing and chattering for the first 15 minutes.
I have a Tundra Toaster (http://www.tundratoaster.com/), same idea as a Red Dragon, but I found it on ebay for $140 (a far cry from what Aircraft Spruce wants for a Red Dragon!). Every heater I've found that uses ambient air rather than combustion air (Herman Nelson, Frost Fighter etc.) shares 3 traits: Very large, very expensive, and 110 volt powered. My little Tundra Toaster fits easily in a small duffel bag with its ducting and a motorcycle battery to run the fan. I do have a 5500 watt diesel generator, but my back aches at the thought of heaving that thing into the back of the truck every time I go flying. I've given thought to getting a small Honda generator and using it to power a Tanis or Reiff preheat system. It might be easier to go out the night before I plan to fly, fire it up, chain the generator to a gear leg then come back the next day, throw a ceramic heater in the cabin while I preflight then take off in my nice warm airplane. I'm not quite ready to throw that kind of money at it yet. As a new airplane owner I'm not as rich as I used to be :)

She's definitely not a shrinking violet and I am anal about ensuring that my passengers are properly dressed for the conditions, but this delicate flower of a pilot would really like to have a warm airplane to sit in (and to not cause excessive wear or damage to the gyros).
Jungle Jim wrote: I use an 1800 watt hair dryer to preheat my Thorp T18. I close up all the openings in the cowl, put the hair dryer to blow on the oil sump. In 30 minutes the CHT goes up from ambient 23-24 degrees F. After about 1/2 hour I pull the cabin heat half way and the hot air goes through the heat overflow into the cabin. I preheat about 45 minutes.
If I had power at my tie-down it would all be so much simpler (unless you've found an 1800 watt 12 volt hair dryer, in which case I'm all ears!). The preheating options when you have access to mains power are endless. I've tried opening the cabin heat and defrost while I run my Tundra Toaster and I could feel a little heat coming out, but not a meaningful amount.
flyinhigh wrote: I have done the exact scenario that you mention with putting the heater into the aircraft. In our case we put in nozzle through the main cabin door, opened the storm window and let her go. After about 30 min there was no condensation, and the plane was hot. Almost like having an APU:)
Maybe it would work better if I left it run for longer and provided for better airflow in the airplane, but I'd still be somewhat concerned about putting all that moisture in the cabin.
---------- ADS -----------
  

GyvAir
Rank (9)
Rank (9)
Posts: 1798
Joined: Mon Mar 12, 2012 7:09 pm

Re: Cabin preheat ideas

Post by GyvAir »

ahramin wrote:Your T18 takes it's cabin heat from the engine compartment? Sounds scary.
I had the same thought when I read it, but after thinking about it a minute it makes sense:
Heat Control.jpg
Heat Control.jpg (183.02 KiB) Viewed 1847 times
---------- ADS -----------
  

pdw
Rank (9)
Rank (9)
Posts: 1479
Joined: Tue Jan 24, 2012 6:51 am
Location: A mile final 24 CYSN

Re: Cabin preheat ideas

Post by pdw »

We have an old Chrysler Dynasty over at the farm with a second/connected midsize battery behind the seat hooked up to one of them Canadian Tire inverters that came on sale for $175 ... a 3000Watt unit. It supports a couple of them cheap home hardware heaters ... on sale for $16.95 last year.

(If the humidity is lower the condensation wouldn't collect on the cold cabin surfaces using that high-flow engine heater.... seeing there Prince George atmossphere got quite high that night in %RH)
---------- ADS -----------
  

ahramin
Rank Moderator
Rank Moderator
Posts: 5907
Joined: Tue Feb 17, 2004 5:21 pm
Location: Vancouver

Re: Cabin preheat ideas

Post by ahramin »

3000W would be overkill to heat the cabin! I didn't realize they made them that big. I guess that's why the second battery, couldn't use a cigarette lighter plug for that.

I_drive_planes, if you can drive your truck up to your plane, maybe you just wire one of those babies into your truck and your problems are solved.
---------- ADS -----------
  

7ECA
Rank 8
Rank 8
Posts: 915
Joined: Thu Jul 03, 2014 4:33 pm

Re: Cabin preheat ideas

Post by 7ECA »

I would't recommend running a hair dryer for such a long period of time, the main reason being the thermistor. The thermistor is designed to kick out, or shut off the appliance if a certain temperature is exceeded, so running one for a long period of time could make that an issue.

And what an issue it would be, if you fire your hair dryer up as an engine heater, only to come back to the plane and have no progress made.
---------- ADS -----------
  

I_Drive_Planes
Rank 5
Rank 5
Posts: 357
Joined: Fri Jan 14, 2005 12:18 am
Location: Prince George

Re: Cabin preheat ideas

Post by I_Drive_Planes »

pdw wrote:We have an old Chrysler Dynasty over at the farm with a second/connected midsize battery behind the seat hooked up to one of them Canadian Tire inverters that came on sale for $175 ... a 3000Watt unit. It supports a couple of them cheap home hardware heaters ... on sale for $16.95 last year.

(If the humidity is lower the condensation wouldn't collect on the cold cabin surfaces using that high-flow engine heater.... seeing there Prince George atmossphere got quite high that night in %RH)
I like this idea so much I'm going to use it! I ordered one of these: http://www.ebay.ca/itm/1500W-Car-Power- ... 20e8357c38 When it comes in I'll pick up a cheap ceramic heater and I should be golden.

I'm seriously thinking about the generator/Reiff solution for next year though (unless I can get the airplane into a hangar in which case it'll be a reiff/extension cord solution). It seems a lot less labour intensive than fiddling with a propane heater and should give a more thorough preheat. I'll be watching Canadian Tire, Princess Auto, and Kijiji for a good deal on a small generator.
---------- ADS -----------
  

justwork
Rank 6
Rank 6
Posts: 479
Joined: Thu Jan 06, 2011 7:59 am

Re: Cabin preheat ideas

Post by justwork »

Buy a little honda or Yamaha generator on kijiji, then a space heater
---------- ADS -----------
  

User avatar
Nark
Rank 10
Rank 10
Posts: 2967
Joined: Thu Feb 19, 2004 6:59 pm
Location: LA

Re: Cabin preheat ideas

Post by Nark »

I stole this idea from a J3 forum elsewhere.

I bought a $20 propane single burner stove. (10,000 btu)
Then spent about $25 at lowes for a 6->4" adapter, a 90* elbow, 4->3" and a 12" tube.

I think she'll do the trick just fine. Puts out enough heat. The exterior doesn't get nearly as hot because of an inner core.
---------- ADS -----------
  
Attachments
image.jpg
image.jpg (721.96 KiB) Viewed 1420 times
image.jpg
image.jpg (857.44 KiB) Viewed 1420 times
Qui desiderat pacem, praeparet bellum
Semper Fidelis
“De inimico non loquaris male, sed cogites"-
Do not wish death for your enemy, plan it.

User avatar
PilotDAR
Rank 11
Rank 11
Posts: 3149
Joined: Sun Sep 30, 2012 6:46 pm
Location: Near CNJ4 Orillia, Ontario

Re: Cabin preheat ideas

Post by PilotDAR »

I would heat the cabin electrically only. Anything else will introduce problems in excess of and benefit. I would not worry about the gyros, or other systems being cold. For the temperature range you'd be willing to fly, they would not be bothered. Just assure everything is warmed up a bit and operating before flight.
---------- ADS -----------
  

photofly
Top Poster
Top Poster
Posts: 7653
Joined: Tue Jan 18, 2011 4:47 pm
Location: Making aviation exhausting, everywhere

Re: Cabin preheat ideas

Post by photofly »

Burning any quantity of propane produces 1.6 times its weight in water; or water of about 80% of the volume of the liquid propane.
---------- ADS -----------
  
Strike me down with all of your hatred & your journey towards the dark side will be complete!

User avatar
hazatude
Top Poster
Top Poster
Posts: 6101
Joined: Fri Feb 11, 2005 4:02 pm
Location: Hamilton
Contact:

Re: Cabin preheat ideas

Post by hazatude »

The Maytoseptember method works best ;)
---------- ADS -----------
  

User avatar
Pop n Fresh
Rank (9)
Rank (9)
Posts: 1270
Joined: Mon Jan 06, 2014 3:46 am
Location: Freezer.

Edited a bunch of times, spelling, adding videos, grammar..

Post by Pop n Fresh »

Nark wrote:I stole this idea from a J3 forum elsewhere.

I bought a $20 propane single burner stove. (10,000 btu)
Then spent about $25 at lowes for a 6->4" adapter, a 90* elbow, 4->3" and a 12" tube.

I think she'll do the trick just fine. Puts out enough heat. The exterior doesn't get nearly as hot because of an inner core.
I like it, except.
photofly wrote:Burning any quantity of propane produces 1.6 times its weight in water; or water of about 80% of the volume of the liquid propane.
Possibly not noticeable in the Bayou with all the nice humidity but up here in winter wonderland once humidity gets frozen into people's car interiors it's the gift that keeps on giving. Frost, fog, moisture...

I would build some form of heat exchanger for that propane heater to separate the moist combustion air from the dry air you want heated then introduced into the cabin. A small computer fan run off a rechargeable battery would be bonus as it would then be a nice forced air heater.

Simplest would be, use a double walled pipe with a 6" diameter elbow on the outer wall, use a 4" sheet metal reducing adapter down to the smallest they have then attach it to the inner wall where the flame will be, cut a hole at the top of the elbow to run that small chimney straight out. Go with the other reducers after the elbow for the dry air into the cabin. Seal the chamber and cut the small computer fan into the side of the outer double wall to push the cool ambient air into your furnace.

Better yet build a heat exchanger chamber around a rocket stove and use a stirling engine to run the fan. Then burn a couple of sticks to make the heat.


This guy's air tank would make a nice heating chamber but is starting to get a bit heavy. You could attach fins to the chimney for better heat exchange.



This guy shows you don't need no fancy pants welding machine to build a rocket stove with an outer chamber.



I like the angle of the wood feed on the top unit because it self feeds.
As the sticks burn they slide down to the fire chamber.
---------- ADS -----------
  

Post Reply

Return to “General Comments”