Oil cooler for heating air

Greg Arehart · #1 02-03-2008, 10:11 PM

I have been reading through the archives and like the idea of using the oil cooler for a wintertime cabin heater (or at least for heating the air coming into the cabin). I noticed that a few people apparently have done this, but I have not seen any photos or detailed discussion in my wanderings through the archives thus far. I would appreciate any comments on how well it has worked, if you have installed such a system, and any links, photos, etc. that would help me to get a handle on what it would take to do such an install.

thanks,
greg

Steve Sampson · #2 02-04-2008, 01:00 AM

Greg, I plan to do exactly that on the -4 I am building, but I have not quite got there yet.

Quite a lot of people are a bit gloomy about the idea, but it is not a big deal because it would not be much work to retrofit a heat muff on the exhaust if it turns out to be useless. Just remember when you make the air gate in the firewall, the air source may change if you decide hot air from the cooler is not a success, and think about that with respect to the routing.

I am in the UK so we dont have Minesotata type cold, but I do plan to put heater elements in the seats also. This is necessary in a -4 anyway, because it is hard to get the heat all the way back there to the wife. Got to keep her warm!

The one slightly complicated bit of the process I see, is to make up a f'glass air collector on the outlet side of the oil cooler. This is more a problem of space in the -4 than anything else though.

All I have to show so far is this, http://gikonfwf.blogspot.com/2008/01...ion.html#links which is nothing really.

There is a bit in the RVator from some years back that is quite positive about this idea.

I hope you get some replies with a bit more to offer than I.

Keep in touch.

PS Some will be concerned about the loss of cooling effect of the oil cooler. -4s tend to run cool I understand, and the -9a I built also ran cool, as does my Supercub. In fact I have never had oil temp problems. I might leave the duct from the oil cooler off for the first few flights, in case I have oil temp problems breaking a new engine in.

mike109g6 · #3 02-04-2008, 01:11 AM

Quote:

Originally Posted by Steve Sampson

Greg, I plan to do exactly that on the -4 I am building, but I have not quite got there yet.

Quite a lot of people are a bit gloomy about the idea, but it is not a big deal because it would not be much work to retrofit a heat muff on the exhaust if it turns out to be useless. Just remember when you make the air gate in the firewall, the air source may change if you decide hot air from the cooler is not a success, and think about that with respect to the routing.

I am in the UK so we dont have Minesotata type cold, but I do plan to put heater elements in the seats also. This is necessary in a -4 anyway, because it is hard to get the heat all the way back there to the wife. Got to keep her warm!

The one slightly complicated bit of the process I see, is to make up a f'glass air collector on the outlet side of the oil cooler. This is more a problem of space in the -4 than anything else though.

All I have to show so far is this, http://gikonfwf.blogspot.com/2008/01...ion.html#links which is nothing really.

There is a bit in the RVator from some years back that is quite positive about this idea.

I hope you get some replies with a bit more to offer than I.

Keep in touch.

PS Some will be concerned about the loss of cooling effect of the oil cooler. -4s tend to run cool I understand, and the -9a I built also ran cool, as does my Supercub. In fact I have never had oil temp problems. I might leave the duct from the oil cooler off for the first few flights, in case I have oil temp problems breaking a new engine in.

There is an article from one of the racing pilots a month or so ago about doing exactly this, pictures and all. I also saw this and thought of using it in the reverse to duct heat off the oil cooler into the cabin heat. http://www.aircraftspruce.com/catalo...es/airduct.php
all that would me needed would be a side duct to dump hot air when not needed.
Mike H 9A/8A

Steve Sampson · #4 02-04-2008, 01:16 AM

Quote:

Originally Posted by mike109g6

There is an article from one of the racing pilots a month or so ago ..........................
Mike H 9A/8A

So where is the article Mike? I would be very interested. Can you scan it in possibly? Thanks

mike109g6 · #5 02-04-2008, 01:42 AM

[quote=Steve Sampson;195671]So where is the article Mike? I would be very interested. Can you scan it in possibly? Thanks[/QUOTE
http://lazy8.net/oil%20cooler%20exit.jpg
I think that it was Nuisance or AJ or one of there buddies. I'm going to PM AJ.
Mike H

N941WR · #6 02-04-2008, 04:54 AM

The varatherm (sp?) controls the flow of oil and only opens up when the engine needs the additional cooling. When it is cold outside, you may get no heat.

Do a search, this has come up before.

Vern · #7 02-04-2008, 05:45 AM

One of my hangermates has been flying with this in his RV-8 for a number of years. He later added heated seats because his rear pax were cold. Then he did a super-seal job on his canopy to eliminate air leaks.

My impression is it does not provide as much heat as the normal muffs.

My opinion: stick as closely to Van's design as possible to eliminate wasted time and money unless you enjoy tinkering more than flying.

deene · #8 02-04-2008, 08:16 AM

I considered an interestering variation to this approach (which someone on the forum mentioned) in which the oil cooler dump air is used to feed the heat muff with the muff output then being used as normal.

The gain in this approach is that you get a free (no further plenum outlets needed) source of "warm" air to drive the heater system. The claim was that the warm source air added to the heat output.

I don't think I will be able to use the system as the routing of the feed scat tubing is difficult in my installation (IO-390/Vertterman exhaust) as the only one good place for the muff is at the front of the engine.

David-aviator · #9 02-04-2008, 08:29 AM

Quote:

Originally Posted by Vern

One of my hangermates has been flying with this in his RV-8 for a number of years. He later added heated seats because his rear pax were cold. Then he did a super-seal job on his canopy to eliminate air leaks.

My impression is it does not provide as much heat as the normal muffs.

My opinion: stick as closely to Van's design as possible to eliminate wasted time and money unless you enjoy tinkering more than flying.

From my Lycoming days in a previous life, I have to agree with Vern. In really cold climes, the oil cooler must be blocked off to get oil temp up 190 or so and there will be no air flow through it at all.

The only time this concept makes any sense is flying high during the summer and you want some cabin heat, but even then it won't be as much as you can steal from an exhaust heat exchanger.

McFly · #10 02-04-2008, 09:04 AM

Quote:

My impression is it does not provide as much heat as the normal muffs.

A friend at my airport modified his 6A to use the oil cooler air as the source for cabin heat. It has worked great for him. A mutal friend who has been in both of our planes on winter night flights says his oil cooler heating system blows mine away (I have Vans anemic heat muff).

It is true that when the vernatherm closes, you are not getting much heat. It is also true that in a decent or using low power settings with a traditional heat muff, you are not getting much heat either.

There are some down sides. It is more heavy and more complated. If you have a cool running engine, it may take some tinkering to get it to work. Good luck.