Anyone have a electric cabin heater in their plane? My favorite times of year to fly are fall and winter so heating the cabin well is something I've been thinking about. I saw these cabin heaters in ACS and think one would fit nicely under the front passenger seat. There are several different models but I'd likely choose the smaller one that draws 30amps and weighs ~3lbs.

http://www.aircraftspruce.com/catalog/eppages/heaters242500.php?clickkey=13289


I don't know how good the cabin heater works on a 172XP but I'm using the xp exhaust on my BH. I figure it will work well for the front passengers but additional heat would be nice for the kids in the rear of the plane.

Much smaller cabin, but I've got front and rear cabin heat from independent muffs using ram air from the back of the baffles. I haven't been able to fully open either one individually yet without sweating, but I've only flown in temps down to the mid- high 30's F.

Is there a possibility to run a rear cabin heat outlet in the BH?

That's where you'll need that 100 amp alternator!

Actually, the XP heater is better than I expected. I don't have a lot of XP time--a little many years ago when a brand new one was on the line at the FBO where I worked part-time, which was used for light SE charter, and then 11 1/2 years ago, while my engine was being built, my IA and my engine builder had one, which they lent to me so I could stay current. Flying at night in late March, the outside temps were in the low 30s, and I was plenty warm in a light jacket.

That's the way it is in my airplane now. When the OATs are in the low 30s, I'm plenty comfortable with a light jacket. As the OATs drop into the 20s, I need a somewhat heavier jacket. Into the teens and below, I need to bundle up. Since I don't ride in the back seat (!), I can't speak to the temp back there. However, I've had passengers in the back in various temps, I make it comfortable for me, and then I tell them if they need it warmer or cooler to let me know. I can't recall ever being asked to adjust the temp.

Cary

CamTom12 wrote:Is there a possibility to run a rear cabin heat outlet in the BH?

Yeah, I could do that but I'm not sure the single heat muff would put out enough heat to make it worth while. It like that idea and hadn't thought of it.

Cary wrote:That's where you'll need that 100 amp alternator!
Cary

Your absolutely right. I was just scrolling through the ACS catalog during breakfast when I saw the heater. I thought, "there's a good use for all the extra alternator capacity."

I looked this unit up. I was thinking hey...maybe put that bad boy into a truck.


MODEL VOLTS / WATTS BTUS PART NO. PRICE
SA12-3000 12V / 360W 6012 05-02121 $208.95
SA12-4000 12V / 480W 8016 05-01966 $218.95
SA12-5000 12V / 600W 10,020 05-03869 $228.95
SA24-2500 24V / 600W 10,020 05-04855 $195.75
SA24-3500 24V / 840W 14,028 05-03870 $219.95
SA24-4500 24V / 1080W 18,036 05-02123 $226.95

I looked at the models and the 12 volt affair maxes out at 600 watts. I wonder just how much heat that would provide and would it be enough. I know the ACA Scout owners love their planes because of the great heater available front and back. There is something to be said for staying warm and comfortable.

Not much heat there compared to a heat muff.... and a 30 amp draw doesn't come without a price. 3 lbs is pretty heavy also. Especially on a hot day in the summer! I guess you could make it easily removable.

Meanwhile, you have a big engine churning away throwing off waste heat like crazy, FREE waste heat (free as in not creating a constant drag via the alternator demands), seems like focusing on capturing more of that waste heat would be better in the long run. The electric heat concept would be a quick and dirty way to go.

Thread drift: Whee, I went to the tree farm behind the old Red Baron hangar yesterday, and based on your input requested the grass between the runway (35) and the taxiway. The bored sounding controller told me sure, but at my own risk. Seeing how it is maybe 200' w by 1500' long, and I had just departed my 18' x 400' strip, and also landed a couple off airport sites on the way, I decided to give it a shot. With the 9 mph headwind and the cool air the landing roll was less then 100' and a real joy compared to landing on all that concrete! Thanks for the tip, now if we could get KPIH to do the same I'd go in there more then once or twice a year. It's always nice to see a little common sense being used rather then 100% rigid adherents to the 'rules."

I agree with Courier....there's tons of heat available from an IO 360. Even if you had to add a second muff, it would make waaaaaay more sense to do that than add one of those heaters.

And, for perspective, a Cessna 206 has one heat muff to heat a much larger cabin than yours.....and I've spent a good bit of time in a 206 in -20 and colder temps. You going to be flying your family around in those kinds of temps?

There are a few things you could do short of adding another muff:

If the muffler doesn't already have heat sinks welded onto the outside, send it to a shop and have some welded on....or just buy a muffler that has them. This increases the heat transfer area available within the muff and thus increases the heat being moved from the muffler to the heater output.

Add an additional heat distribution system to provide heat to the back seat area. Put it on a separate control, so you can control front vs back seat heat separately. The front seats will be getting some heat off the firewall, the backs won't.

In my experience, the reason some airplanes have minimal cabin heat isn't because there's not enough heat available from the exhaust muff, but rather because the system wasn't optimized to produce the maximum FLOW of heated air. The Husky is a classic example of that. There is HUGE heat in that muffler, but the flow of air through the heat shroud is minimal. A lot of that is because of certification issues that you won't have to deal with. But, design in lots of flow, and that heat shroud and muffler will provide plenty of heat, and much more than one of those electric heaters.

There are lots of airplanes running around northern and interior Alaska with warm cabins and no electric heaters. Just look at your system and design a good distribution AND flow design.

Thirty amp draw continuous is pretty large. I wouldn't want one of those things in my airplane, and that amount of heat is minimal, frankly, compared to what that exhaust system will put out.

Consider the average twin engine airplane.....if these electric heaters were a good idea, why wouldn't every light twin have two or three of them, instead of those Janitrol heaters, burning gasoline, and potentially causing all sorts of problems?

MTV

Had one in a Navajo at one time. It was nice because it always worked. The installation was actually an STC. The heater was installed under the pilots seat to blast his cold feet. After glueing shut and plugging the numerous air leaks the airplane was plenty warm without it so it got removed. It was nice to have when the janitrol heater quit working.

Pilatus pc12 has two electric heaters and an optional third. They are 1500w each. King air also has an electric heater.

It seems counter-intuitive, but too much airflow can reduce heat as much as not enough airflow. For example- I've seen old electric forced air furnaces used for temporary heat on construction jobs. Often, they don't put out much heat. But if you block off part of the air inlet (usually with a piece of scrap drywall), it reduces airflow to where there's a higher "delta t". That's temperature differential, in other words temperature rise through the heating coil. Higher airflow, the air's moving too fast to absorb much heat. I increased the amount of cabin heat available in my old C150/150TD by blocking off part of the scoop at the front baffles which collected air for the heat muff. Less air but at a lot higher temperature.

On my trip to Alaska in the Top Cub last year, this particular bird had a length of scat hose run to the back seat for the poor bastard who would be sitting back there when it was in use by the USFW. It was HOT!

King Air 200's use bleed air for cabin heat. I'm not aware of what the others use, though.

Whee, I can take pics of my set up later if you like. I have independent SCAT tubes, muffs, and knobs/valves for front and rear though. And LOTS of available air from the pressure side of the baffles.

MTV's flow commentary has validity. I have the full Flo-vent system in my airplane, so that there are two exits for the air coming in, in the shelf just below the back window. If that air is coming off the heater, the whole airplane is warmer than if I didn't have the system.

Cary

746 watts = 1 horsepower (plus attenuation) = 0.16gals/ hour

Heat muff = 0 horsepower = 0.0gals/ hour

Small reciprocating aircraft were generally not designed for large electrical loads. Opinion.

8GCBC wrote:746 watts = 1 horsepower (plus attenuation) = 0.16gals/ hour

Heat muff = 0 horsepower = 0.0gals/ hour

Small reciprocating aircraft were generally not designed for large electrical loads. Opinion.

Does the physical load increase with current draw? Or is it constant for a given alternator?

Zzz wrote:

8GCBC wrote:746 watts = 1 horsepower (plus attenuation) = 0.16gals/ hour

Heat muff = 0 horsepower = 0.0gals/ hour

Small reciprocating aircraft were generally not designed for large electrical loads. Opinion.

Does the physical load increase with current draw? Or is it constant for a given alternator?

current being generated = proportional (increasing with amps) load on the engine = fuel flow = HP = heat = less range = $

I always look at the bottom line ($)

Whee,

The guys that built the exhaust on my plane have one that'll fit an IO-360 and provide two heat muffs: http://www.aircraftexhaust.net/dual-3-i ... haust.html

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Can Tom12 wrote
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The guys that built the exhaust on my plane have one that'll fit an IO-360 and provide two heat muffs: http://www.aircraftexhaust.net/dual-3-i ... haust.html
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Wow ...rack up one more advantage for Experimentals. Of course some planes like the ACA Scout seem to have all the heat they need.

The back seats of the Bearhawk gets pretty cold.

The heater does a fine job for the front two, but the big problem is outside air leakage. We can be "ok" up front, while water is freezing in bottles in the baggage area.

Cold air gets in at all sorts of places, and seems to accumulate in the back of the cabin. If I were going to try to make our plane warmer, it would be a second heat muff and direct heat to the back seats combined with efforts to better seal the cabin doors with doubled seals, to create a sort of basic labyrinth seal.

Denali wrote:

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Can Tom12 wrote
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The guys that built the exhaust on my plane have one that'll fit an IO-360 and provide two heat muffs: http://www.aircraftexhaust.net/dual-3-i ... haust.html
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Wow ...rack up one more advantage for Experimentals. Of course some planes like the ACA Scout seem to have all the heat they need.

The ACA aircraft do have great heaters. My citabria cooked me out in -20 if I wanted it to. But dress to egress is a must, so I didn't really like having it that warm.