Center (above Gear well) Fresh Air Vent in M20F

[Echo]

I met a local Mooney owner that has an M20F Model.  Very nice airplane with Johnson Bar.  He had a feature I had not ever seen before.  In the center of the plane (above the gear well) there is a wonderful fresh air vent!  What years was this standard on, or was this a modification?  I only have pilot side ram air at knee and center below panel (between legs) fresh air...as well as weak overhead vents.  I really like this set-up.  My plane is a 65E.  the center gear "hump" is low and there is open space up to the panel vs. my 66E that had this area enclosed.  He gave me a lift up to pick up my plane after first annual and this feature was my "wow" FACTOR 10.   

[Hank]

It's in my 1970 C. As a guess, it started in '69 when electric gear became standard; it would interfere with the Johnson bar. C, E, F, probably together. 

[Echo]

43 minutes ago, Hank said:

It's in my 1970 C. As a guess, it started in '69 when electric gear became standard; it would interfere with the Johnson bar. C, E, F, probably together. 

This owner of an F model has Jbar on his plane.

[Andy95W]

My 1967 M20C had that.  Must’ve started sometime in 1967.

Wish my 1964 had that.

[Igor_U]

The vent you are referring to is the part 26 on the picture.

IPL says it's first introduced on 1967 and it is working very well on my M20F. Having said that, the Louver assy (inside the part 34) does have an air leak and sometimes opens on it's own since the handle that opens it does not have enough friction. Vent is plastic and had some cracks I needed to repair when I bought my plane but 19 years later repairs are holding well.

 

 

[Shadrach]

4 hours ago, Hank said:

It's in my 1970 C. As a guess, it started in '69 when electric gear became standard; it would interfere with the Johnson bar. C, E, F, probably together. 

Huh? Pics please. I have a large vent in tge center console. The plumbing is on top of the nose wheel well.

[Shadrach]

2 hours ago, Igor_U said:

The vent you are referring to is the part 26 on the picture.

IPL says it's first introduced on 1967 and it is working very well on my M20F. Having said that, the Louver assy (inside the part 34) does have an air leak and sometimes opens on it's own since the handle that opens it does not have enough friction. Vent is plastic and had some cracks I needed to repair when I bought my plane but 19 years later repairs are holding well.

 

 

Pretty sure my vent is aluminum. The only plastic is the wheel well trim. 

[Shadrach]

@Echo is this the vent to which you’re referring?

 

[skydvrboy]

What?!  I have a '67 F and I'm almost positive I don't have that vent.  I certainly don't get any airflow from anything in that area.  Maybe it was added part way through the production year?

[Shadrach]

4 hours ago, skydvrboy said:

What?!  I have a '67 F and I'm almost positive I don't have that vent.  I certainly don't get any airflow from anything in that area.  Maybe it was added part way through the production year?

Your F is technically a 1967 model per the 670 prefix of the serial number, but it was built in September of 1966. Must have been manufactured just before the vent was added to production.  
Probably not a lot of demand for these components in the salvage market. I bet that you could collect the parts for a retrofit without much trouble. Adding the controls would likely be the most difficult part.

So the sole heat source in your cabin is the footwell blast tubes?

[Echo]

12 hours ago, Shadrach said:

@Echo is this the vent to which you’re referring?

 

That is it.  I finally have F envy after all these years.   

[Echo]

Well it appears 67 is the lucky year for this add.  Enjoy.  Yes, I only have blast furnace.

[Ragsf15e]

Oh man, if it’s cold in the backseat, that vent can blast the heat directly back there too… yeah, that’s a good one to have!

[Shadrach]

20 minutes ago, Echo said:

Well it appears 67 is the lucky year for this add.  Enjoy.  Yes, I only have blast furnace.

So is all of the heat delivered to the cabin via the footwell tubes and defroster?

I would guess that Mooney added that center vent because heat for the rear passengers was marginal in a short body and even less so with an extra 10 inches added to the cabin. 
It is nice to have in the summer for fresh air, but it’s absolutely critical in the winter for keeping back seaters warm.

[Mellow_Mooney]

26 minutes ago, Shadrach said:

So is all of the heat delivered to the cabin via the footwell tubes and defroster?

I would guess that Mooney added that center vent because heat for the rear passengers was marginal in a short body and even less so with an extra 10 inches added to the cabin. 
It is nice to have in the summer for fresh air, but it’s absolutely critical in the winter for keeping back seaters warm.

Are you saying that this vent can deliver cold air as well as heated? Couldn’t imagine ever using this in the summer on my F

 

curious if I’m missing a switch or something now… 

[Hank]

46 minutes ago, Mellow_Mooney said:

Are you saying that this vent can deliver cold air as well as heated? Couldn’t imagine ever using this in the summer on my F

 

curious if I’m missing a switch or something now… 

When I pull the Cabin Vent knob in my C, fresh outside air comes out of this vent. When I pull the Cabin Heat knob, hot air comes out of this vent. In the winter, even in Ohio, I usually run a mixture of both, rarely over 50% hot air.

The defroster is turned on by turning the valves on the two footwell heat lines, which also blow hot air when Cabin Heat is pulled.

The roof vent is opened and closed by rotating the knob on the ceiling panel between the speakers, and the footwear fresh air vents are opened and closed individually. 

I am blissfully unaware of any ventilation or heat in the back seat, other than the two overhead vents.

[Ragsf15e]

49 minutes ago, Mellow_Mooney said:

Are you saying that this vent can deliver cold air as well as heated? Couldn’t imagine ever using this in the summer on my F

 

curious if I’m missing a switch or something now… 

Yes, it does both.  There’s a mixing box that mixes fresh vent air from the right naca vent and hot air from the heater.  Temperature is dependent on how you pull the heat and vent knobs. I was just working on my mixer box last weekend.

[Shadrach]

8 hours ago, Mellow_Mooney said:

Are you saying that this vent can deliver cold air as well as heated? Couldn’t imagine ever using this in the summer on my F

 

curious if I’m missing a switch or something now… 

Yes. The supply to the center vent comes from the “mixing box” on the firewall. The “mixing box” has a hot air input and a fresh air input. The output from the mixing box can be all fresh air, all hot air or any combination of the two to achieve the desired air temperature into the cabin. The mixing box feeds the footwell gate vents, the center vent and the defrost. The only fresh air only vents in my plane are the overhead vents and the pilot’s side Wemac “ball cooler”.  Everything else can be blended to get the desired output temp.

Edit- Rags beat me to it…

[skydvrboy]

9 hours ago, Shadrach said:

So the sole heat source in your cabin is the footwell blast tubes?

My setup is about the same as yours except for missing the center vent.  The mixing box leads to the footwell, defrost, and to a small slot behind the pilot seat.  In the winter, the copilot is burning up, pilot is hot, back left seat is cold, and back right is nearly frozen. That center vent would sure help even out the temps between the various seats.

Direct fresh air vents are the eyeball by the pilots left leg and the overhead vents.  The rear overheads put out a lot more air than the front.

 Do you have a way to change the amount of air diverting to the defrost?  Mine is open to all heat vents at all times. I don’t have any valves on the tubes in the footwells.

[Igor_U]

2 hours ago, skydvrboy said:

 Do you have a way to change the amount of air diverting to the defrost?  Mine is open to all heat vents at all times. I don’t have any valves on the tubes in the footwells.

The only way to increase the amount of air to defrost is to close the air at the footwell tubes and close the vent in the middle effectively forcing air towards the windshield.

 

 

[Igor_U]

20 hours ago, Shadrach said:

Pretty sure my vent is aluminum. The only plastic is the wheel well trim. 

Ross,

It's been more then 15y how I worked on it when refinishing the interior panels so I can't be sure. I remember being gray, assembled of two halves but would need to have a look to be sure.

I though that Valve Assy shown below is only metals piece.

I should really call LASAR and see if this is still available for a spare. List price is $33 and I can easily see hours of labor in this sheet metal marvel. 

 

  

[Shadrach]

3 hours ago, skydvrboy said:

My setup is about the same as yours except for missing the center vent.  The mixing box leads to the footwell, defrost, and to a small slot behind the pilot seat.  In the winter, the copilot is burning up, pilot is hot, back left seat is cold, and back right is nearly frozen. That center vent would sure help even out the temps between the various seats.

Direct fresh air vents are the eyeball by the pilots left leg and the overhead vents.  The rear overheads put out a lot more air than the front.

 Do you have a way to change the amount of air diverting to the defrost?  Mine is open to all heat vents at all times. I don’t have any valves on the tubes in the footwells.

Defrost is always on to some degree. Defrost can be increased by choking off the rest of the outlets. Defrost is strong enough to melt light rime on the windshield.

[Shadrach]

1 hour ago, Igor_U said:

Ross,

It's been more then 15y how I worked on it when refinishing the interior panels so I can't be sure. I remember being gray, assembled of two halves but would need to have a look to be sure.

I though that Valve Assy shown below is only metals piece.

I should really call LASAR and see if this is still available for a spare. List price is $33 and I can easily see hours of labor in this sheet metal marvel. 

 

  

The fact that it ever had a list price of $33 makes me wonder if it was adapted from another application.   Mine gets way too hot to be plastic. I’ve hit the louvers with an infrared thermometer at max heat and they were just under 200°. I can’t imagine plastic taking heat cycles like that for 57 years without degradation.

[Utah20Gflyer]

My 68 G model has the center vent.  

[skydvrboy]

19 hours ago, Igor_U said:

The only way to increase the amount of air to defrost is to close the air at the footwell tubes and close the vent in the middle effectively forcing air towards the windshield.

I have never been able to find a way to close the air at the foot well tubes.  Mine looks like it just has a bunch of open holes with no way to close them.  Maybe I'm missing something.  It would sure be nice to be able to shut those vents holes in the foot well tubes so the copilot seat doesn't get so hot.