A/C in A/C

[CBarber]

Air conditioning in Aircraft.

 

John Slade….and others.

 

I recall that you really wanted to install air conditioning in your Cozy at one time. IIRC, SWMBO, Char, really liked the idea too.

What has become of that plan now that the plane is flying. Is it less of an issue now that you have turned into a “damned Yankee”….uh, sorry, I mean moved up north (heck, I thought “damn-Yankee” was one word ‘till I as twenty-three yoa ).

 

Ok, maybe this is rhetorical since I will be attempting it anyway but my close friend Blain Streeter owns the company that supplies air conditioning units to the likes of Cirrus, Cessna, Moony etc. Based on my superior persuasive skills...and the luck of the draw, Blain is working with Velocity, Inc to provide very nice, very light (relatively) a/c systems to Velocity owners.

 

Being the great guy he is, Blain has offered and has provided the parts to install this system in my plane as and R&D project….even though all the systems are proven and certified in other airplanes. My bird allows him hands on experience with a Velocity/canard/homebuilt. He is putting one in the RV-7 he is building (he also has a Bonanza…tough life). I am on a non-disclosure as to pricing but he made me an offer I could not refuse.

 

IIRC, his unit is over 30% lighter that what the manufacturers were using and if fully automatic.

 

So, other than me just bragging at my good fortune, what are ya’lls thoughts on A/C in A/C? In Houston on the ramp in spring, summer and fall there is a very good argument for the extra weight, cost and complexity, however, since I am also a lawyer, I can argue the other side too in that they are superfluous.

 

I would enjoy others musings on the issue while I determine my next engine rebuild and retrofitted install.

 

All the best,

 

Chris

[Cozy Girrrl]

As long as it can sense when you are in need of power (climb) or coolant temps are high or trending upwards, it should cut out automatically rather than contribute to the system stress. Its a twofold negative in that it takes horsepower to run the compressor and the condenser wants to live in -front- of the radiator, both minuses but the condenser bothers me the most as you cannot "turn it off" like you can the compressor.

Not saying it cannot be done, not saying do not do it, just needs some smart control and a smarter controller when the smart switch fails to do its job.

I've heard that like in Southern Florida on a hot humid summer day you could pass out taxiing on the tarmac in a closed plane without A/C. I remember gardening in my yard in Houston during the summer, insane.

...Chrissi

[CBarber]

The system is all electronic and does cut out in climb and high temps. Everything is automatic. It astonishes me how well thought out the system is. It is apparant it is designed by real pilots for real airplanes.....even if for those pilots with pretty deep pockets;) . The load of the compresor is minimal compared to systems of just a few years ago. I have some pix of the Velocity, Inc install should anyone be interested....I think Blaine said it was ok to post 'em. I will check to verify. I don't recall if it is still in the prototype model at Velocity, Inc and what their feelings are. Blaine did say I could discuss it though as I think it is pretty kewl...no pun intended....well, maybe a bit.

 

Hopefully my project will be a flying advertisment for his system as I hope he can offer it to the general homebuilt community. If not him, through Velocity, Inc as they have always been pretty good about allowing non-Velocity builders purchase items from them. If curious the name of his company is Seamec...uh, perhaps Seamech?

 

Oh, and in my install the condensor in not currently slated to be in front of the radiator. My radiator was/is too big to fit under the engine with the Velocity cowl, however the condensor is much smaller and should fit. It is where Velocity, Inc is installing it in the Lyc installations, fed by a very small and thin belly scoop. So a bit of drag for a even cooler airplane....ok, that time the pun was intended.

 

All the best,

 

Chris

[lhendrick]

Any estimates of total A/C system weight because we would be carrying the total weight whether we are using the system or not.

 

Cost also comes into play. I recall A/C being up there in the $15-22K as an option on some high end planes.

 

As of now I'm thinking of a bag of ice in my lap. Get in hot plane, ice cools you off, ice melts - water evaporates - no weight penalty - climb to altitude - cooler air - voila, Burt would smile.

[Cozy Girrrl]

The high dollar ones make the "cooler full of ice with fans" units they sell for $500 seem a lot more reasonable though with all of the experince one has by the time they finish their canard aircraft I dare anyone to buy one instead of cobble it up themselves shame on you!

I only know anything about a/c systems due to studying holding plate systems in yachts and workboats, you have to design a system made out of parts that will take a eutectic plate down to -40F so that you can have ice cold beer and spare ice for umbrella drinks in the Sea of Cortez in August with only one hour of run time per 24 hrs.... the necessities of life you know? Anyhow it helps if the key components of such systems are made from parts available in junkyards and auto supply stores for when they break..everything on a boat breaks.... hmmm, sounds like an aeroplane?

The unfortunate part of designing an A/C system for a plane is that it has its highest load when it is going to have its worst heat transfer on the condenser..while nearly static on the ground. So you are carrying around extra condenser area plus a fan? You might think about installing 2 AN-4 nutplates either side of that intake scoop for the condenser, then mold a fan housing with a gasket and an 8" industrial muffin fan used for equipment cooling. You're going to warm up that rotary anyway so turn on the A/C and Ground Power Fan. Probably be better if it clipped on so it would break away and go through your IVO prop when you forget to disconnect it?

...Chrissi

[Edge 513]

Yea, What Chrissi said. If you found you really wanted a swamp cooler.

Plus you could glass a custom fit and shaped to the rear seat footbed unit that would fit beautifully behind the left front seatback and be an in and out appliance. [changing from a 4place to 3 place airplane- but still allowing nothing intruding into the adjacent passenger seat for comforts sake.] Run a cigarette adapter for power and have a top mounted hopper for ice- a drain. I wonder how compact it could be, cubic inches wise, and still function well?

[Cozy Girrrl]

I don't want to hijack Chris's very valid thread Edge, -but- these $500 units are average red plastic cooler with white lid, you'll see them for sale in the buildings at Osh, fan housing on top, extension cord to plug into 12v, outlet flange for 3-4" dryer ducting. If you did a labrynth of aluminum plates with an airgap between for the airflow and packed ice above and below you would get frostbite.

 

...sorry Chris, it's all Edge's fault

[CBarber]

No worries. I enjoy the discussion. I have wondered about these alternative cooling units too. "Aviation Consumer" has done a couple of reviews on them. If you subscribe you can access the articles online.

 

I do not know how seriously I would have been about the A/C but this unit kinda fell out of the sky into my lap. Who am I to look the gift horse in the mouth. Also, I have vivid memories of how really hot it does get on the ramp. I have had sweat so thick streaming into and burning my eyes that I almost didn't want to go fly. I hear it is not as bad in the Velocity with the gull wings up, but I doubt it is pleasant.

 

All the best,

 

Chris