Electric AC Compressor?

Check this out and see if it gives you any ideas:

http://www.flightlineac.com/kits_

Just slap an 'EXPERIMENTAL' sticker on the 310 and call it good. ;)

Engine driven pumps. It's easy when you make that leap, tons of suppliers for those, and commercial automotive condensers, evaps, lines, driers. It's not rocket surgery if you can drive off the engine.
 
Engine driven pumps. It's easy when you make that leap, tons of suppliers for those, and commercial automotive condensers, evaps, lines, driers. It's not rocket surgery if you can drive off the engine.

The factory Cessna system on the 310 utilized an automotive compressor with an electric motor to turn it.
 
The factory Cessna system on the 310 utilized an automotive compressor with an electric motor to turn it.

The Bonanza system uses an auto compressor driven off the engine. I think Piper did the same.
 
They also have electric systems, which is what I was referencing Ted towards.

http://www.flightlineac.com/engine_off_systems

Ah, cool (pun intended). :yesnod:

Edit: Looks like they have a ~50 amp service for the whole system. If we take out about 12 amps to drive the evap blowers, that leave roughly 32 amps to drive the DC comp motor. Not bad. I wonder if they have the evap blowers on the hot side of the bulkhead, or if they have to shed the heat load of the blowers on the cool side? I always like a system that keeps the blower motors on the hot side so they don't load the cool side and reduce efficiency.
 
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I'm smelling a 337 to be required here.
 
30,000 BTU's of cooling on 1260watts of input power (45Amps X 28V)?


Ah, cool (pun intended). :yesnod:

Edit: Looks like they have a ~50 amp service for the whole system. If we take out about 12 amps to drive the evap blowers, that leave roughly 32 amps to drive the DC comp motor. Not bad. I wonder if they have the evap blowers on the hot side of the bulkhead, or if they have to shed the heat load of the blowers on the cool side? I always like a system that keeps the blower motors on the hot side so they don't load the cool side and reduce efficiency.
 
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30,000 BTU's of cooling on 1260watts of input power (45Amps X 28V)?

"With the flexability offered by this technology, we can provide 8,500 to 30,000 BTU to your cabin space and even more with dual units.

The total electric requirements for most systems is as little as <45 amps at 28 volts. Humidity, ambient heat load, and restrictive pressure against the blower and condenser motors, all raise the amp draw on any system, so please read about our other components in order understand that we address the power consumption issue from every possible direction.

The Truth About Electric Air Condition Compressors

There has been a lot of speculation and misinformation concerning the electric compressor. Engineering truth is engineering truth. Somethings we know all there is to know. Other things we are adding new theory to what was previously known and building on our new discoveries and failures and designing much greater effieciency into our newer designs. The latter is true of air conditioning compressors as well as electric motors.

Two types of systems are used for producing air conditioning from electricity. The first utilizes an electric motor that drives an automotive compressor with a belt. This type of system is very effective as an airconditioning unit, but to this date the electrical requirements to turn the compressor and effectively cool large cabin space with high heat sink is far too great without voltage changes greater than 28 volts or currency draws in excess of 65 Amps. The second type of system is modeled after the hermetically sealed design in cold storage units (refrigerators and freezers). High voltage and current draw have also been a problem for these units until rotary and scroll compressor technology had some very incredible engineering advances over the last 5 years. Flightline's systems are custom manufactured in DC brushless models that we can then use in a number of ways that was not previously possible. Coupling the advances of our compressor design to the advances in heat exchanger technology, allow once unsatifactory technology to be the best pound for pound producer for air conditioning.

Flightline's advances in air conditioning technology allow 28 volts to produce what other manufacturer's require 48 volts and 100 amps to produce. Flightline utilizes the variable voltage conditions of our compressors to maximize their efficiency at 28 volts. Still capable of operation within the 20 to 50 voltage range, 28 volts has been maximized because of our desire to not require higher or mixed voltage in an aircraft. Combine Flightline's electric compressor with our evaporator and our multi-pass, parrellel flow condenser technology, and you have a complete system weighing only 50 lbs that requires 45 amps, with higher capability than that of units weighing 65-85 lbs using 48 volts and 65-100 amps."

Ask them, I just got what I got from the web material. Nor did I say they got 30k BTUs from that current. So, direct your questions to the builder.
 
Ask them, I just got what I got from the web material. Nor did I say they got 30k BTUs from that current. So, direct your questions to the builder.

Sorry if you're offended. I don't suspect of you of being the manufacturer.

I'd like to see independent testing of their equipment to verify their claims. I'm always suspicious of product data claims. There was a guy selling an electric heater for preheats that managed to have more output than input. I think Sportys was selling it. I called the manufacturer and he tried to convince me that he measured it and had a college professor verify his claims - right.
 
"Lisa invented this perpetual motion machine - it just keeps going faster and faster. LISA! IN THIS HOUSE WE OBEY THE LAWS OF THERMODYNAMICS!!!"
 
So if you are smelling a 337, how about using the Cessna system? I think it would make getting the approval easier.
 
So if you are smelling a 337, how about using the Cessna system? I think it would make getting the approval easier.

Agreed. Question is finding one that I can buy and getting it for a reasonable price.
 
regarding your fan question...
its often a game of specsmanship. expect any published number to be for the fan in free air unless otherwise noted. if you are lucky enough to get a number for the fan as installed in the housing, remember that all the ductwork will reduce it even further... especially spiral wirewound duct.
 
The Masterflux, iirc, is a variable-speed unit, using their controller. I believe the one-piece is around $3700, but cannot find my valuable notes.

Edit:

How 'bout $3500?

http://www.downriversupply.com/displaybyMfg.php?pageNum_rsItems=2&totalRows_rsItems=73&mfgCode=458

Now to find a good, easy evaporator/blower.

Definitely higher than what I wanted to spend, but might make sense. I do like the fact that it's a simply constructed unit. Might have to ask them some questions.
 
Definitely higher than what I wanted to spend, but might make sense. I do like the fact that it's a simply constructed unit. Might have to ask them some questions.

If I had 28 volts, this is where I'd be going. Simple, straightforward, not a lot of moving parts.
 
The Bonanza system uses an auto compressor driven off the engine. I think Piper did the same.

The factory system on Bonanzas is a Sanden 508 compressor, belt driven, with a 14 or 28v clutch as appropriate. The pilot sits on the evaporator and in older models, the cold air comes from vents in the lower console.

The condenser sits in a pod roughly under the cargo area. It retracts and extends depending on the mode.

The STCed FTA aftermarket AC also uses a engine driven compressor, however the condenser sits in the tail, along with most everything else. Heat exchange over the condenser is done by an electric fan that kicks on as necessary. Cold air is piped in through an overhead duct to eyeball vents. The controls, including the heat controls are replaced with a digital control/servos. The rear seats can even bias their temp to some degree. All in all, a very neat system, and the price is reasonable (17k installed, if I recall).

Richman
 
So if you are smelling a 337, how about using the Cessna system? I think it would make getting the approval easier.

I keep hearing 337. I would think with some ingenuity a 337 wouldn't be a problem. You configure the system as truly removable. Then you get the 337 ONLY on the parts of the aircraft that must be modified without the AC system installed. I'm thinking a 337 to cover the change to skin for ducting, the drain, the anchor points for the AC system and maybe the power run to connection point. The 337 would NOT include the AC system ... it would be removable.

Would this be a kosher approach? I think it would meet both the letter and the intent of the law. You get a 337 if you need to run a new cigarette lighter plug to the panel, but you don't 337 the entire AHRS based EFIS you plan to run on your iPad, right? This wouldn't be much different, would it?
 
If I had 28 volts, this is where I'd be going. Simple, straightforward, not a lot of moving parts.

I absolutely agree with the pros. The cons as I see it are the high cost and also the solder connections for freon vs hose connections. I worry about the longevity with vibrations. I do think an automotive based setup would likely be more reliable in that regard, but maybe because I'm more familiar with it. The cons with the automotive system are having to add an electric motor to power the compressor.

I keep hearing 337. I would think with some ingenuity a 337 wouldn't be a problem. You configure the system as truly removable. Then you get the 337 ONLY on the parts of the aircraft that must be modified without the AC system installed. I'm thinking a 337 to cover the change to skin for ducting, the drain, the anchor points for the AC system and maybe the power run to connection point. The 337 would NOT include the AC system ... it would be removable.

Would this be a kosher approach? I think it would meet both the letter and the intent of the law. You get a 337 if you need to run a new cigarette lighter plug to the panel, but you don't 337 the entire AHRS based EFIS you plan to run on your iPad, right? This wouldn't be much different, would it?

That was the original idea, and the idea seems to work well for Arctic Air and the people who buy their freon units.

In the 310 I am trying to NOT place something in the main cabin. Keep in mind our plane is regularly filled to the brim with dog crates or luggage. Taking away from that space hurts the mission of the plane. The hat rack is an acceptable area for a system, but otherwise it needs to go behind the bulkhead. At that point I think you fall outside of what could be considered temporary.
 
The factory system on Bonanzas is a Sanden 508 compressor, belt driven, with a 14 or 28v clutch as appropriate. The pilot sits on the evaporator and in older models, the cold air comes from vents in the lower console.

The condenser sits in a pod roughly under the cargo area. It retracts and extends depending on the mode.

The STCed FTA aftermarket AC also uses a engine driven compressor, however the condenser sits in the tail, along with most everything else. Heat exchange over the condenser is done by an electric fan that kicks on as necessary. Cold air is piped in through an overhead duct to eyeball vents. The controls, including the heat controls are replaced with a digital control/servos. The rear seats can even bias their temp to some degree. All in all, a very neat system, and the price is reasonable (17k installed, if I recall).

Richman

I was looking at Sanden compressors last night. They publish performance curves including horsepower requirements. It does look like a 1-1.5 HP electric motor would be sufficient to drive one, but I need to run some more math to see what the results would be BTU wise. Benefit is easy to build and low cost.
 
Ted,
There are systems made for trucks that are all electric. They're called "no idle" systems because they can operate with the truck's engine shut down. I don't have any experience with them. I just found information about them on the internet.

I understand these system are becoming more popular because of all the "no idle" truck parking areas.

Just google "no idle ac system"

Dave
 
Dave,

Checked that out. There are some components that might work, but I think on the whole the systems won't do quite what I want to.

I did find what might be some good evaporator setups:

http://www.nostalgicairparts.com/ac/evaporator-units-6.php

The in-dash units look promising, although at ~290 CFM a bit lower than what I'd like to see. But if that's the installed airflow, that might not be too bad, and the BTU advertised capacity is within the range I'm interested in.

This one has more on the BTUs, but I don't think would mount the way I want:

http://www.nostalgicairparts.com/air-conditioning/ud-550-overhead-roof-mount-evaporator-unit-483.php
 
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