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RV-14 Air Conditioning
- Thread starter RViator60
- Start date
AC starts at 3500 feet! (is what others have done 
)
It's really only useful on the ground but these systems take a bit to cool the cockpit down so they are really limited on the actual relief from the heat they provide. I think the general consensus is it's not worth it.
)It's really only useful on the ground but these systems take a bit to cool the cockpit down so they are really limited on the actual relief from the heat they provide. I think the general consensus is it's not worth it.
It's for ground operations primarily in hot and humid North Carolina summers. I didn't come across a lot of VAF post related to A/C, so not sure what you mean by general consensus...although I think my wife's opinion trumps that anyway. Hopefully I'll come across someone with some first hand experience with it.
There are some RV-10's with AC installed, that's probably your best resource.
Here in central Alabama, I feel your pain
Those brutal summer days on the tarmac really sweat the pounds off
I think the consensus (just from reading discussions over the years) is that while it seems like a great idea, the extra complexity [and expense] isn't worth the meager cooling you get in the cabin [when you need it most]. You're generally off the ground before the air inside is cooled significantly and at altitude it's just not needed.
But with that said .. happy wife, happy life
Here in central Alabama, I feel your pain
Those brutal summer days on the tarmac really sweat the pounds off I think the consensus (just from reading discussions over the years) is that while it seems like a great idea, the extra complexity [and expense] isn't worth the meager cooling you get in the cabin [when you need it most]. You're generally off the ground before the air inside is cooled significantly and at altitude it's just not needed.
But with that said .. happy wife, happy life
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Adding the exhaust extensions and the big evaporator housing on the belly has to cost cruise speed.
Climb rate is a function of (1) power excess to that required for level flight at the same speed, and (2) weight. The engine driven compressor eats some of the available excess, and the system has a weight cost.
There is a indirect effect too; engine driven compressor installs usually require a hole in the inlet ramp for the bracketry and drive belt, a huge cooling leak.
I will now don my old married guy hat. We all consider the wife's comfort, as we wish to keep the gas and hangar dollars flowing. However, some (not all) wives don't actually fly very often. The vast majority of flight time is solo or with a buddy.
So, for some minor part of a minor part of your flight time, you are cool. The rest of the time, you have the slowest cruise, lowest climb rate, and highest CHT of all your flying buds...which is not so cool.
Climb rate is a function of (1) power excess to that required for level flight at the same speed, and (2) weight. The engine driven compressor eats some of the available excess, and the system has a weight cost.
There is a indirect effect too; engine driven compressor installs usually require a hole in the inlet ramp for the bracketry and drive belt, a huge cooling leak.
I will now don my old married guy hat. We all consider the wife's comfort, as we wish to keep the gas and hangar dollars flowing. However, some (not all) wives don't actually fly very often. The vast majority of flight time is solo or with a buddy.
So, for some minor part of a minor part of your flight time, you are cool. The rest of the time, you have the slowest cruise, lowest climb rate, and highest CHT of all your flying buds...which is not so cool.
I put this b-Kool swamp cooler in my 14-A in July and August, works great for the first hour in Texas at 98 degrees, keeps the temp manageable on the ground. $299 Keep the wife cool for sure!
https://www.b-kool.net/product-details.html
https://www.b-kool.net/product-details.html
Air Conditioning
I suggest you call Bill Genevro (Airflow Systems) at 949-218-9701 and ask him about the installation and also for names and contact numbers of RV-14 owners with the system. I know he worked with a builder to install the first unit in an RV-14 a couple of years ago, so there is at least one and likely more.
I have the Airflow Systems A/C in my RV-10 and am glad I have it during the Houston area summers. While the amount of cooling from the system is reduced when you are at idle speed on the ground, it is still an improvement over not having A/C. And unless you are doing most of your flying above ~6000 ft. during the summer time, the outside air temp is still hot.
As for the ice chest coolers, based on my experiences with one in my Grumman AA-5, they are not worth the effort or cost. I gave up using one I bought a few years ago at Air Venture after just a couple of uses, as the ice was completely melted in the first 15 min., and getting the ice chest in and out of the back of the plane, particularly when full of melted ice, caused me to overheat more than the amount of cooling that came from it during flight.
Just my opinions based on my personal experiences.
I suggest you call Bill Genevro (Airflow Systems) at 949-218-9701 and ask him about the installation and also for names and contact numbers of RV-14 owners with the system. I know he worked with a builder to install the first unit in an RV-14 a couple of years ago, so there is at least one and likely more.
I have the Airflow Systems A/C in my RV-10 and am glad I have it during the Houston area summers. While the amount of cooling from the system is reduced when you are at idle speed on the ground, it is still an improvement over not having A/C. And unless you are doing most of your flying above ~6000 ft. during the summer time, the outside air temp is still hot.
As for the ice chest coolers, based on my experiences with one in my Grumman AA-5, they are not worth the effort or cost. I gave up using one I bought a few years ago at Air Venture after just a couple of uses, as the ice was completely melted in the first 15 min., and getting the ice chest in and out of the back of the plane, particularly when full of melted ice, caused me to overheat more than the amount of cooling that came from it during flight.
Just my opinions based on my personal experiences.
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Not meaning to argue, but I have flown with ice chest coolers (Artic Air) in a Cardinal and a Dakota. Both worked well on the ground and in the air. The ice lasted surprisingly well. Both pilots left the coolers in their planes during the hotter months and used the built-in pump to remove melt water, only adding ice for flight. Their planes were hangared, so were not heat-soaked to start. A/C is probably better, but you will pay different penalties. Good luck with your decision.
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10 lbs of ice absorbs 1,440 Btu's by the time it is completely melted. A compact car AC unit will do at least 14,400 Btu's per hour. So you'd need to have the capability to melt 100 lbs of ice per hour to get what your Prius can do.
In my case, I live in SoCal and it takes at least 20 min from taxiing from my hangar to getting outside of Class B and climbing to cooler air. I tried one of those icebox coolers too and the 10 lbs of ice I started with were gone within 15 min. At that point I was still schlepping that 20 lbs of warm water with icebox for the rest of the trip and getting no benefit from it. And, I still have to descend and land at the end where I'm sweating again. No thanks.
In my case, I live in SoCal and it takes at least 20 min from taxiing from my hangar to getting outside of Class B and climbing to cooler air. I tried one of those icebox coolers too and the 10 lbs of ice I started with were gone within 15 min. At that point I was still schlepping that 20 lbs of warm water with icebox for the rest of the trip and getting no benefit from it. And, I still have to descend and land at the end where I'm sweating again. No thanks.
Thanks for your comment so far. I think I will use this post to document my journey to designing, installing, and testing A/C in my RV-14A under way to learn from the experience and knowledge of this great community of builders and to perhaps help other RV-14 builders with the same goals.
Part 1
A/C or not?
I live in a hot and humid climate so I'm looking for a traditional A/C system not only to cool the cabin air during ground ops but also to reduce humidity in the cabin, making me, but more importantly my wife, much more comfortable. To me, that really rules out the ice chest approach, although it may work well for others.
Scoop or no scoop?
Since I most need cooling/dehumidification during ground ops with the engine in idle and not moving or moderately taxiing, I think the actively cooled condenser will give me better performance on the ground then the external scoop. There is of course greater potential for CO entrainment that must be considered, but without the potential loss in aerodynamic performance.
Power considerations
What I've seen so far suggest the typical compressor will consume around 4-5 HP and 15-20 Amps in a 14 V system. The IO390 should have plenty of HP to spare and 70 Amp alternator should provide the electrical power needed, but the latter still needs to be confirmed.
The attachment is a rough schematic of what the system might look like.
Part 1
A/C or not?
I live in a hot and humid climate so I'm looking for a traditional A/C system not only to cool the cabin air during ground ops but also to reduce humidity in the cabin, making me, but more importantly my wife, much more comfortable. To me, that really rules out the ice chest approach, although it may work well for others.
Scoop or no scoop?
Since I most need cooling/dehumidification during ground ops with the engine in idle and not moving or moderately taxiing, I think the actively cooled condenser will give me better performance on the ground then the external scoop. There is of course greater potential for CO entrainment that must be considered, but without the potential loss in aerodynamic performance.
Power considerations
What I've seen so far suggest the typical compressor will consume around 4-5 HP and 15-20 Amps in a 14 V system. The IO390 should have plenty of HP to spare and 70 Amp alternator should provide the electrical power needed, but the latter still needs to be confirmed.
The attachment is a rough schematic of what the system might look like.
Awesome! Will be following, interesting project for sure!
What does it weigh? CG will be a serious consideration with gear that far back in the empennage ... depending on what the compressor offsets you'll have to add weight up front
Curious to the size of the compressor, not a lot of room up there ...
Also, your elevator linkage and elevator and yaw AP servos occupy space around that second bulkhead, the one aft the baggage bulkhead, fyi.
CG Considerations:
Prop: The blended foil Van's recommended Hartzell prop is the heaviest
Battery: EarthX sheds like 9 pounds over the PC680, iirc, but generally recommended
Alternator: Probably need the 60amp?
Edit: Just a thought ... if you install the new top access panels you can creatively shift avionics forward ...
What does it weigh? CG will be a serious consideration with gear that far back in the empennage ... depending on what the compressor offsets you'll have to add weight up front
Curious to the size of the compressor, not a lot of room up there ...
Also, your elevator linkage and elevator and yaw AP servos occupy space around that second bulkhead, the one aft the baggage bulkhead, fyi.
CG Considerations:
Prop: The blended foil Van's recommended Hartzell prop is the heaviest
Battery: EarthX sheds like 9 pounds over the PC680, iirc, but generally recommended
Alternator: Probably need the 60amp?
Edit: Just a thought ... if you install the new top access panels you can creatively shift avionics forward ...
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Regarding CO entrainment, note there is no actual requirement to bring in outside air. Every auto AC includes a "MAX" or "recirculate" control. When selected, the system has no outside air intake. It's really what you want if the goal is primarily ground cooling. Or you may wish to implement it as a selectable the feature, just like your car.
The climb rate loss for 5 hp will be roughly 80 FPM.
Check alternator output at idle speed, not rated RPM.
Marty,
I assume your diagram is just a schematic and doesn't reflect exact location of air inlet/outlet? The enclosed system that I'm familiar with has the condenser air fully enclosed, taking it in through the belly, through the condenser, and then back out through the belly, with the airflow being driven by a fan. I don't think you will want the exhaust air out of the condenser to be just dumped into your tail cone.
Also, you will need 2 electric fans with this system, one for the condenser and one for the evaporator. From what I understand, on the RV-10 system like this the total max current draw is about 30+ amps! See post #10 to this thread: https://vansairforce.net/community/showthread.php?t=187446
Regards
I assume your diagram is just a schematic and doesn't reflect exact location of air inlet/outlet? The enclosed system that I'm familiar with has the condenser air fully enclosed, taking it in through the belly, through the condenser, and then back out through the belly, with the airflow being driven by a fan. I don't think you will want the exhaust air out of the condenser to be just dumped into your tail cone.
Also, you will need 2 electric fans with this system, one for the condenser and one for the evaporator. From what I understand, on the RV-10 system like this the total max current draw is about 30+ amps! See post #10 to this thread: https://vansairforce.net/community/showthread.php?t=187446
Regards
RV-14A A/C Update
I finished installing and running A/C in my RV-14A and wanted to summarize the project for anyone interested or just curious. Details will be high level in this post but happy to drill down further as requested.
Air conditioning is supplied by a custom-build system installed during construction. Flightline AC (Redmond, OR) supplied the primary system components. A key design criteria was to use an engine-driven compressor and incorporate the condenser and electric powered fan within the aft fuselage behind the baggage bulkhead.
Key features of the system includes:
- Engine driven compressor with dual pulley ring gear
- Modified induction air plenum and baffling
- Electrical forced air condenser
- Custom designed evaporator and fan
- Conditioned air plenum
A summary of the modifications are as follows:
- The single pulley ring gear was replaced with an original Lycoming dual pulley ring gear.
- An a/c compressor installed on the left side forward accessory pad with a custom bracket. A belt was identified and installed and the compressor aligned with the drive pulley on the ring gear.
- The left side forward engine baffling was modified to accommodate the compressor while providing airflow to cool the engine
- The induction and alternate air system was redesigned and relocated.
- The lower cowling was modified with a separable induction air scoop and to provide space for the fuel mixture, throttle, and induction air control cabling.
- Refrigerant lines were firesleeved and run over the engine and through the firewall and along the fuselage floor to the aft fuselage.
- Condenser suction and discharge vents were installed with boots on either side of the fuselage
- The condenser and fan was installed in the aft fuselage and connected to the air vents with scat tubing
- The evaporator was installed and mounted to the baggage bulkhead access panel.
- A fiberglass cold air plenum was fabricated and installed to direct conditioned air to the forward cabin.
- A harness was fabricated and installed.
- Refrigerant hoses were fabricated and installed
- The receiver/dryer was installed.
- A drain hose was installed
I recently flew my RV-14A (N818PP) out Oregon to see John Strain at Flightline A/C to look over my install and recharge the system with his more advanced equipment. 19 oz of R-134A was required and the evaporator outlet temp reached 42F. Total current draw is 30-40A.
What a pleasure to be able to sit on the tarmac with the canopy closed on a hot and humid North Carolina summer day and have my passenger feel perfectly comfortable. I'll be at Air Ventures this year for anyone interested in seeing the install first hand.
I finished installing and running A/C in my RV-14A and wanted to summarize the project for anyone interested or just curious. Details will be high level in this post but happy to drill down further as requested.
Air conditioning is supplied by a custom-build system installed during construction. Flightline AC (Redmond, OR) supplied the primary system components. A key design criteria was to use an engine-driven compressor and incorporate the condenser and electric powered fan within the aft fuselage behind the baggage bulkhead.
Key features of the system includes:
- Engine driven compressor with dual pulley ring gear
- Modified induction air plenum and baffling
- Electrical forced air condenser
- Custom designed evaporator and fan
- Conditioned air plenum
A summary of the modifications are as follows:
- The single pulley ring gear was replaced with an original Lycoming dual pulley ring gear.
- An a/c compressor installed on the left side forward accessory pad with a custom bracket. A belt was identified and installed and the compressor aligned with the drive pulley on the ring gear.
- The left side forward engine baffling was modified to accommodate the compressor while providing airflow to cool the engine
- The induction and alternate air system was redesigned and relocated.
- The lower cowling was modified with a separable induction air scoop and to provide space for the fuel mixture, throttle, and induction air control cabling.
- Refrigerant lines were firesleeved and run over the engine and through the firewall and along the fuselage floor to the aft fuselage.
- Condenser suction and discharge vents were installed with boots on either side of the fuselage
- The condenser and fan was installed in the aft fuselage and connected to the air vents with scat tubing
- The evaporator was installed and mounted to the baggage bulkhead access panel.
- A fiberglass cold air plenum was fabricated and installed to direct conditioned air to the forward cabin.
- A harness was fabricated and installed.
- Refrigerant hoses were fabricated and installed
- The receiver/dryer was installed.
- A drain hose was installed
I recently flew my RV-14A (N818PP) out Oregon to see John Strain at Flightline A/C to look over my install and recharge the system with his more advanced equipment. 19 oz of R-134A was required and the evaporator outlet temp reached 42F. Total current draw is 30-40A.
What a pleasure to be able to sit on the tarmac with the canopy closed on a hot and humid North Carolina summer day and have my passenger feel perfectly comfortable. I'll be at Air Ventures this year for anyone interested in seeing the install first hand.
The empty weight including A/C components was 1335 and CG was within the design CG range. Since the components are built-in during construction, I don't have a before weight, but I would estimate they added about 100 lbs.
Peltier for cooling
Has anyone ever considered using a peltier for creating a personal cooling option in the cabin? The point being that simply having some cool air blowing on you can make a would of difference. You don't have to cool the whole cabin. As these are small solid state devices they can be placed much more easily then an evaporator coil. The primary down side is that they are not very efficient, but I suspect with 120 watts, you could get quite a lot of cooling. If you have ever seen one of the ice coolers that plug into a cigarette lighter, that is what they use. There would be much to design to come up with a working solution, but I suspect it could be smaller and cheaper, although not a full AC system.
Has anyone ever considered using a peltier for creating a personal cooling option in the cabin? The point being that simply having some cool air blowing on you can make a would of difference. You don't have to cool the whole cabin. As these are small solid state devices they can be placed much more easily then an evaporator coil. The primary down side is that they are not very efficient, but I suspect with 120 watts, you could get quite a lot of cooling. If you have ever seen one of the ice coolers that plug into a cigarette lighter, that is what they use. There would be much to design to come up with a working solution, but I suspect it could be smaller and cheaper, although not a full AC system.
I’m wondering if anyone with the exp119 setup has installed a/c? The fuel injection air inlet is where the compressor needs to go. Pictures would be helpful.
