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Air Conditioning Advice

949Aviator

I'm New Here
Is it worth putting air conditioning in? Currently in my Cessna A/C is going to 10k. There have been times at say Vegas or Palm Springs where A/C sure would have been nice. Is the additional weight in the plane, cost, and extra complications worth it?
 
My personal opinion, but I have never understood the air conditioning thing in an RV. The airplane climbs so well that it's only a couple minutes until the outside air temp is dropping noticeably, and they have excellent air ventilation for those few minutes. In exchange for AC for those few minutes of flight you are paying high dollar and adding 40-50 pounds to the airplane that you have to haul around for every flight hour, reducing your payload and looking for a time to break and add maintenance cost, as well as loading the engine during takeoff/climbout when you least need the parasitic loss.

I just don't get it - and I live in west Texas where 100+ is an everyday summertime norm.
 
An RV gets to 10k' exceptionally quickly. "Climb and maintain 72 degrees."
 
But!!!

RV's may be able to climb fast but when it's hot enough to use AC, keeping the engine cool can be a problem. We have been down in the heat (100*+), throttled back to keep the oil and CHT's out of the red, and been able to climb at only 100-200 fpm.

There's also airspace concerns (at least out here on the left coast), that prohibits climbing to cooler temps. So sure, RV's may be able to climb fast, but AC can provide passenger relief when it's hot and you're down low or on the ground. You have to decide if it's worth the effort and weight penalty.

If I were building my -10 I would install it without blinking.

-Marc
 
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RV's may be able to climb fast but when it's hot enough to use AC, keeping the engine cool can be a problem. We have been down in the heat (100*+), throttled back to keep the oil and CHT's out of the red, and been able to climb at only 100-200 fpm.

There's also airspace concerns (at least out here on the left coast), that prohibits climbing to cooler temps. So sure, RV's may be able to climb fast, but AC can provide passenger relief when it's hot and you're down low or on the ground. You have to decide if it's worth the effort and weight penalty.

If I were building my -10 I would install it without blinking.

-Marc

Thread Drift, but if you have an RV that can only climb at 200 fpm due to cooling concerns, it's not a weather or air conditioning issue - you've got severe baffling or mixture problems.
 
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Thread Drift, but if you have an RV that can only climb at 200 fpm due to cooling concerns, it's not a weather or air conditioning issue - you've got severe baffling or mixture problems.

+1

I am able to climb at 2500 and WOT all the way to 14K with CHTs below 400, assuming I run 25* of advance, on 90* days in my 10. My oil temps get to 225 in the climb, but I am OK with that and doesn't warrant a bigger cooler for me (it drops back to 185 once I level off). If I don't dial the advance back to 25, I can get 430+ CHTs. I feel for the Pmag guys that can't dial back the advance. After 7-8K', the stock EI advances are simply too much for the less dense air while in a ROP climb. You're losing power and generating excess heat.

Larry
 
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Installing in a -10

I live in the DFW area, have family in Tucson. So, yeah. My RV-10 will have A/C in it. Already bought in. Soon will be installed. Long taxi, waiting for clearance, flying in bravo around DFW at 3500ft in 90F weather is not enjoyable for myself or anyone else in the plane.

YMMV
 
My wife made the decision easy for me. When she agreed to my building the RV-10, she stated that if I wanted her to fly with me it needed to have A/C. Made my decision very easy.

I also find it very nice to have on hot Houston area summer days during taxi, takeoff, and when in the pattern for landing. I'm glad I installed in in my RV-10.
 
My personal opinion, but I have never understood the air conditioning thing in an RV. The airplane climbs so well that it's only a couple minutes until the outside air temp is dropping noticeably, and they have excellent air ventilation for those few minutes. In exchange for AC for those few minutes of flight you are paying high dollar and adding 40-50 pounds to the airplane that you have to haul around for every flight hour, reducing your payload and looking for a time to break and add maintenance cost, as well as loading the engine during takeoff/climbout when you least need the parasitic loss.

I just don't get it - and I live in west Texas where 100+ is an everyday summertime norm.

Ditto this for me. All the extra complexity, weight, and electrical loads, for the minimal times that you would use it most places, makes it a "no way" for me. Even on a hot/humid day (I'm in Indiana), we would be at 8K plus feet in no time enjoying free air conditioning, cruising to our destination. The standard temperature lapse is 2 degrees Centigrade, or 3-1/2 degrees Fahrenheit, for every thousand feet you climb:). Stay lighter, keep it simpler, go faster, and farther on the same fuel than an air-conditioned 10.
 
+1

I am able to climb at 2500 and WOT all the way to 14K with CHTs below 400, assuming I run 25* of advance, on 90* days in my 10. My oil temps get to 225 in the climb, but I am OK with that and doesn't warrant a bigger cooler for me (it drops back to 185 once I level off). If I don't dial the advance back to 25, I can get 430+ CHTs. I feel for the Pmag guys that can't dial back the advance. After 7-8K', the stock EI advances are simply too much for the less dense air while in a ROP climb. You're losing power and generating excess heat.

Larry

Well Larry, you are just a special guy! VAF is rife with stories about keeping the engine cool during hot weather ops.

Yeah, if my plane hasn't been run and I get it and start climbing, I an do pretty good at keeping the temps under control. But if I fly somewhere that has an OAT of 100+ degrees, then land for fuel and try to climb out of there.... Well lets just say it's a slow climb until I get to cooler weather. :eek:

Wish you were closer to look over my system and figure out why I have problems like several other VAF members. ;-)

-Marc
 
I polled the group years ago, and something like half were not satisfied with their cooling setup.

One thing for sure. Cutting a hole in the left inlet ramp for an AC compressor drive belt is definitely not going to improve anyone's climb rate.
 
Or a second alternator to run the A/C...actually I wonder about a transformer to step it down to 12v as system redundancy. Probably easier to have a second alternator at 24v than to run everything as 24v.

Another advantage of an electrically driven AC compressor is pre-cooling the aircraft. Plug it into a power source and cool down the cabin before hopping in and starting the engine. The old King Air 100 series was great for that.


My wife made the decision easy for me. When she agreed to my building the RV-10, she stated that if I wanted her to fly with me it needed to have A/C. Made my decision very easy.

That is certantly an easy decision!
 
This one is a tough one, living here in the south and having a wife that isnt going to tolerate the temporary heat makes me want to do an a/c but I feel like current systems are not worth it. Really wish there was an easy way, an all electric would be fantastic.
 
Something like this:

car_ac_1-thumb.jpg
 
This one is a tough one, living here in the south and having a wife that isnt going to tolerate the temporary heat makes me want to do an a/c but I feel like current systems are not worth it. Really wish there was an easy way, an all electric would be fantastic.

I have the same issue. The heat is a problem with the wife and kids in the Florida sun. I also agree the current systems are not the answer. I looked long and hard for a solution I liked (Oshkosh, Sun N Fun, web, etc) and could not find one so I am building one for market. Waiting on some laser cut parts then I can put some pictures up of the proof of concept. It is 12 volt variable speed conpressor, all electric, and removable. Should weigh approx 40 pounds all up.
 
Or a second alternator to run the A/C...actually I wonder about a transformer to step it down to 12v as system redundancy. Probably easier to have a second alternator at 24v than to run everything as 24v.

Another advantage of an electrically driven AC compressor is pre-cooling the aircraft. Plug it into a power source and cool down the cabin before hopping in and starting the engine. The old King Air 100 series was great for that.

That is certantly an easy decision!

I looked at a 110VAC portable system for my 10. Unfortunately, once I accounted for inverter efficiency loss, the 90 amp alternator (highest amperage I could find in a form factor that fit) just wasn't enough, especially on the ground. I also found a decent setup for truck cabs that runs on 12 volts that could easily be adapted for installation behind the baggage bulkhead. However, that puts 45-50 lbs behind the baggage wall and I thought that was simply too much loss in carrying capacity. It also creates issues on the ground, as it is drawing much more than the alternator is putting out at idle RPMs (it needed around 50 amps at max cooling rate, which is most needed on the ground). I didn't like the idea of launching into the sky without full battery capacity, as I am electrically dependant. Adding another 20 lbs of battery back there just created more weight issues.

Larry
 
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I have the same issue. The heat is a problem with the wife and kids in the Florida sun. I also agree the current systems are not the answer. I looked long and hard for a solution I liked (Oshkosh, Sun N Fun, web, etc) and could not find one so I am building one for market. Waiting on some laser cut parts then I can put some pictures up of the proof of concept. It is 12 volt variable speed conpressor, all electric, and removable. Should weigh approx 40 pounds all up.

I probably speak for many, I wish you much success!!! and hope to benefit from effort :D
 
Size matters. If your 6’04 and 230 lbs the extra 40-70 pounds of weight added on makes a difference when useful load is important. If your 5’09 and 170 pounds you can sacrifice some useful load.
 
After 200 hours flying my 10 I can honestly say I've used AC close 95% of the time. Yes it's added cost, complexity, and is just something else that can break... but if you prefer comfort over speed, useful load and you fly a good bit in warmer climates than I would seriously consider AC.

I do most my flying with one passenger, maybe two. I can think of two times that I had the plane loaded with 2 adults and 2 kids.
 
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