heating for the back seats in an M20F

[podair]

Hi I fly a 1967 M20F and the heating works wonderfully well. However it seems very little hot air makes it to the back row. Has anyone found an easy way to redirect some of the flow to the back seats? I often fly at high altitude and in winter my little passengers complain they are freezing while my toes are very warm.... I am wondering if you can fit a little duct from one of the small footwell hot air duct to funnel some of the heat to the back. The center hot air vent blasts a lot of hot air too but not that much finds its way to the back. Even in summer it used to be an issue too, but I fitted new door and baggage doors seals and that seems to have solved the problem when it is not too cold outside! Still need a winter solution... Had to fly at 15k feet on Friday and it was -20c outside....

 

[Piloto]

There is not much you can do to provide hot air to the back seats. The problem is not unique to Mooneys but even on cars. Best and cozy solution are the hot blankets. You can see them at http://www.sportsimportsltd.com/12votrhebl.html?gclid=CMG4xdPv16UCFZdS2god4lBfmw They work very well and kids love them.

José

[carusoam]

Podair,

One of the things you can check for the back seaters is the spider of air ducts that deliver warm air to each of the four locations.

The airbox is under the co-pilot side.  Air delivery, as you know is based on the position of the two slide gates, one for hot air across the muff and the other fresh air from outside.  Lubricate both gates for best operation.

After that, there are four hoses that leave this air box.  The pilot and copilot have the ability move a gate over the air supply to each of their respective positions.  When these two gates are closed (they don't close completely) it sends the most amount of air to the back seats.

I replaced all of the hoses in my M20C to improve flow to the back seats.  The original 40+year old hoses were crushed and did not flow much.  Check to see where the air exits the side walls at each back seat.

Overall,  Check the quality of the hose, verify there is no blockage to the back seats, close the two front air gates and stay below 10,000 ft in the winter....

note: above 10k, the engine does not generate much heat.  Air flow through the cabin is intense.  Air temperature is cold.  Have you ever been in an old VW beetle (rear mounted air cooled engine - does not put enough heat forwards in the winter - feel sorry for brothers in Long-EZs).

I found that a blanket that reaches up through the space between the seats is a good way to flow warm air to the back.

I have not investigated Piloto's response yet.

-a-

[flight2000]

What year was your C?  The only thing I have is the center vent that "throws" the heated air towards the back between the front seats.  I don't have any other air vents in the back seat area other than the overhead air vents from the airscoop.  I also have the heater vents near the pilot/copilot's feet.  Wonder if it is a design varience between the different models or years?  My center counsel is significantly different from my friends 65 E as an example.

I thought about getting a small, simple ceramic heater that you can plug into the cigerette lighter.  They are also great for pre-heating the cabin before firing up the engine.

Brian

 

 

[podair]

thanks for all the suggestions. The electric blankets sound great , but how much current draw can I take from the cigar lighter? The link provided above suggests 6-8amps.

Also my vent configuration sounds very familiar to flight2000s'. Unfortunately, I don't have all the mods and fantastic panel he has... nice work, flight2000, I might actually take a lot of inspiration from your website in future updates for OYDFD

Patrick

 

[flight2000]

Thanks.  I appreciate that.  Feel free to use away or ask any other questions you might have.

Brian

[carusoam]

Mine was 1965 M20C.  No upgrades except a single piece windshield and some updated nav/coms along the way.

Thinking harder.  Airbox under co-pilot side has two hoses coming out of it.  One hose went to pilot side, other went to right side passenger.

The pilot airbox had one hose coming out of it that went back to the left side passenger. 

If the co-pilot airbox "damper" is open, there is not enough pressure to force air down the other tubes.

If the pilot side airbox damper is open, then there is not enough pressure to force air down to the left side passenger.

If you have the original side wall material (God bless you), there is a plastic trim ring outlining the hose exit.

Check your air boxes under the instrument panel to see if the original black, wire supported (sceet, scat or whatever) tubing is there or has connection capabilities under there.

Then go improve the main cabin door seal and make it so the overhead air vents stop leaking.  The vent supplying the radios with -20 air can also be blocked until the air warms up a bit.  (look for the T off of the outside air supply air.)

I refreshed my air tubing and interior panels all at one time.

If that doesn't work.  The 94M20R seams to be much more air tight and a better generator of heat.

Best regards,

-a-

[Clarence]

The problem in keeping your Mooney warm may not be lack of heat but too many air leaks in the cabin.  We take care of a Bravo whose owner complained of poor heating and a cold cabin.  We spent a lot of time sealling holes in the cabin.  Leaks from the wheel wells enter the area under the floor then enter the cbin through the floor.  Another area is the wire pass from the baggage area to the battery compartment.

Remember that Mooney spent a lot of time in production sealing and taping all of the cabin joints, over the years these seals deteriorate and are damaged by maintenance and avionics tech.  Spend time looking for and sealing leaks for a warm cabin.

Clarence Beintema

C-FMYB M20E

 

 

 

[GeorgePerry]

One thing I did that really helped was put some foam over the rear seat louvered vents.  It's pretty easy.  I cut out two dense foam pads approx 4x4x1 inch that I used to fill the vent holes.  First step is to remove a few screws that hold on the rear interior panels.  Yous shouldn't have to remove the entire panel, just a few screws so the rear portion of the panel can be lifted away from the fuselage just behind the rear seats.  Once you have access then all you have to to is "stuff" the foam into the vent holes to fill them.  The foam will fit snugly between the two bars of the cage and fill up the holes to keep the cold out.  To finish just reinstall the screws that hold the trim panel.  The enitire process only takes about 10 minutes and is easily reversed for the summer months.  I had Air Mods in NJ take some pics of the stripped interior of my old plane when they were updating the interior.  I've encluded Pics to show the location of the interior and exterior louvered vents.

This simple and inexpensive "weatherproofing" step makes a huge difference in rear seat temperature and cut down significantly on the cold air drafts that were circulating around the cockpit.