Go Back   EcoModder Forum > EcoModding > EcoModding Central
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 06-02-2008, 03:16 PM   #1 (permalink)
EcoModding Lurker
 
Join Date: Jun 2008
Posts: 1
Thanks: 0
Thanked 0 Times in 0 Posts
Question Insulating cold a/c lines?

I run without the a/c when I can, but here in New Orleans it can get terribly hot in traffic. Would insulating the cold a/c lines inprove a/c efficiency? Why isn't this done from the factory?

  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 06-02-2008, 04:12 PM   #2 (permalink)
Pokémoderator
 
cfg83's Avatar
 
Join Date: Dec 2007
Location: Southern California
Posts: 5,864

1999 Saturn SW2 - '99 Saturn SW2 Wagon
Team Saturn
90 day: 40.49 mpg (US)
Thanks: 439
Thanked 528 Times in 355 Posts
CHEGAI -

Welcome to EM! I think insulating the lines would help. I think that you want to insulate the "cold" lines leading from the AC to the cabin, right?!?!?!? Someone smarter than me will chime in.

CarloSW2
__________________

What's your EPA MPG? Go Here and find out!
American Solar Energy Society
  Reply With Quote
Old 06-02-2008, 04:15 PM   #3 (permalink)
EcoModding Apprentice
 
Join Date: Dec 2007
Location: Ventura, Ca
Posts: 112

Whoop's Wheels - '89 Honda Civic Wagovan
90 day: 39.09 mpg (US)
Thanks: 1
Thanked 9 Times in 7 Posts
Yes it will help some. You can purchase split insulation hose from Home Depot or someplace like that. On a lot of car's the lines are insulated. I think the manufacturers also count on the fact that it's hose, so maybe they figure those sections won't make that much a difference. It probably won't be noticeable, in terms of mileage, but it should also help the level of cool you can get, since you won't be cooling the engine compartment, so much.
  Reply With Quote
Old 06-02-2008, 04:44 PM   #4 (permalink)
igo
Master EcoModder
 
igo's Avatar
 
Join Date: Dec 2007
Location: Wheeling, WV
Posts: 410

Mini Box Truck - '05 Scion Xb
90 day: 32.87 mpg (US)

It FITs - '09 Honda Fit Sport
90 day: 36.2 mpg (US)

Impreza - '13 Subaru Impreza Sport
90 day: 30.92 mpg (US)
Thanks: 12
Thanked 14 Times in 10 Posts
What ever you use for insulation make sure that it will be able to withstand hot under hood temps.
  Reply With Quote
Old 06-03-2008, 01:57 AM   #5 (permalink)
Master EcoModder
 
Ryland's Avatar
 
Join Date: Jan 2008
Location: Western Wisconsin
Posts: 3,904

honda cb125 - '74 Honda CB 125 S1
90 day: 79.71 mpg (US)

green wedge - '81 Commuter Vehicles Inc. Commuti-Car

Blue VX - '93 Honda Civic VX
Thanks: 867
Thanked 433 Times in 353 Posts
Make sure that the hose you are insulating isn't part of the high pressure side or you may be holding heat in, instead of holding cold in, this would put a higher load on your A/C, if the A/C system was designed correctly this should already be the case so it shouldn't matter that they are not insulated.
  Reply With Quote
Old 06-03-2008, 04:57 PM   #6 (permalink)
EcoModding Lurker
 
Join Date: Apr 2008
Location: Colchester, CT
Posts: 38

POS - '97 Ford Aspire
90 day: 47 mpg (US)
Thanks: 0
Thanked 1 Time in 1 Post
this is how A/C works in your car:

- The compressor increases the pressure (and temp) of the LP vapor (R-134a).
- It then goes to the condensor (the 'radiator' in front of the coolant radiator) where heat is removed (read temp dropped) until the R-134a condenses (still at or above ambiant temp). it is still at high pressure.
- the high pressure liquid then flows to the evaporator in the cab (usually under the dash or in a compartment in engine bay passenger side against the firewall)).
- in the evaporator, the R-134a aquires the 'latent heat of vaporization' from the ambiant air in the cab. this heat transfer cools the air flowing over the evaporator. this is when the R-134a gets cold (going from liquid to gas).
- the vapor then returns to the compressor.

Insulating the condesner-to-evaporator line will do nothing, as this liquid is warm already. the time spend in the line means that if there is much of a temp difference, the amount of heat transfered will be neglible (meaning you will spend more money on insulation than you save in gas and you will not be able to measure a any temp difference in the cab).

if you want your system to be more efficient, insulate the cab and ensure your system has the proper amount (not too much or too little) R-134a in it. If you converted from R-12 to R-134a, you will need a bigger condenser to get the same cooling since R-12 is much more efficient of a refrigerant than R-134a.

so, save your time/money for an eco-mod that will work
__________________
  Reply With Quote
Old 10-01-2009, 03:08 AM   #7 (permalink)
aero guerrilla
 
Piwoslaw's Avatar
 
Join Date: Oct 2008
Location: Warsaw, Poland
Posts: 3,541

Svietlana II - '13 Peugeot 308SW e-HDI 6sp
90 day: 58.1 mpg (US)
Thanks: 1,056
Thanked 630 Times in 396 Posts
Today someone at the Polish Peugeot-Klub forum posted that he insulated his A/C line. It was a 2 minute job and he reports a slight improvement. I attached his photo, as you can see the A/C line runs between two very hot things: the radiator and the engine.
Attached Thumbnails
Click image for larger version

Name:	klima.jpg
Views:	1523
Size:	61.9 KB
ID:	4347  
__________________
e·co·mod·ding: the art of turning vehicles into what they should be

What matters is where you're going, not how fast.

"... we humans tend to screw up everything that's good enough as it is...or everything that we're attracted to, we love to go and defile it." - Chris Cornell

Piwoslaw's Peugeot 307sw modding thread

  Reply With Quote
Old 10-01-2009, 01:04 PM   #8 (permalink)
.........................
 
darcane's Avatar
 
Join Date: Aug 2009
Location: Buckley, WA
Posts: 1,586

Ninja 650R - '06 Kawasaki Ninja 650R
90 day: 52.02 mpg (US)

B*tch - '01 Honda Civic HX
Team Honda
90 day: 38.09 mpg (US)

Ms. Hyde - '06 Cadillac CTS V
Sports Cars
90 day: 16.93 mpg (US)
Thanks: 375
Thanked 480 Times in 311 Posts
Quote:
Originally Posted by rocket View Post
this is how A/C works in your car:

- The compressor increases the pressure (and temp) of the LP vapor (R-134a).
- It then goes to the condensor (the 'radiator' in front of the coolant radiator) where heat is removed (read temp dropped) until the R-134a condenses (still at or above ambiant temp). it is still at high pressure.
- the high pressure liquid then flows to the evaporator in the cab (usually under the dash or in a compartment in engine bay passenger side against the firewall)).
- in the evaporator, the R-134a aquires the 'latent heat of vaporization' from the ambiant air in the cab. this heat transfer cools the air flowing over the evaporator. this is when the R-134a gets cold (going from liquid to gas).
- the vapor then returns to the compressor.
You missed one critical element of an A/C system: the expansion valve (sometimes just an oriface). This valve is between the condensor and the evaporator and this is where the refridgerant transitions to low pressure and cools off in the process.

Before the expansion valve, you WANT it to dissapate heat, so it is not really helpful to add insulation. The ONLY part of the system that insulation would help is after the expansion valve and before the evaporator. I've seen this already in place on some newer cars, but a lot of manufaturers place the expansion valve so close to the evaporator that insulation is pointless.

Mike
__________________
2001 Civic HX Mods


Past Cars:
CTS-V

2003 Silverado Mods
  Reply With Quote
Old 10-02-2009, 05:23 AM   #9 (permalink)
EcoModding Apprentice
 
Join Date: Jun 2009
Location: stl
Posts: 139

rusty - '00 ford mustang coupe
90 day: 24.31 mpg (US)

cbr929 - '00 honda cbr929 fast
90 day: 39.54 mpg (US)

Porshe - '06 Kawasaki zx10r
90 day: 47.21 mpg (US)

truck - '96 ford ranger
90 day: 26.51 mpg (US)
Thanks: 5
Thanked 11 Times in 8 Posts
don't forget about condensation, if you do decide to wrap the lines, make sure that water has a place to go.
  Reply With Quote
Old 10-02-2009, 06:40 AM   #10 (permalink)
aero guerrilla
 
Piwoslaw's Avatar
 
Join Date: Oct 2008
Location: Warsaw, Poland
Posts: 3,541

Svietlana II - '13 Peugeot 308SW e-HDI 6sp
90 day: 58.1 mpg (US)
Thanks: 1,056
Thanked 630 Times in 396 Posts
Quote:
Originally Posted by nemesis View Post
don't forget about condensation, if you do decide to wrap the lines, make sure that water has a place to go.
Yeah, this problem was mentioned on that forum. If the pipe is insulated, then water will still condense on it, but will take much longer to evaporate, and that may lead to corrosion.

__________________
e·co·mod·ding: the art of turning vehicles into what they should be

What matters is where you're going, not how fast.

"... we humans tend to screw up everything that's good enough as it is...or everything that we're attracted to, we love to go and defile it." - Chris Cornell

Piwoslaw's Peugeot 307sw modding thread

  Reply With Quote
Reply  Post New Thread


Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Comparing Warm Air Intakes (WAI) & Cold Air Intakes (CAI) toomuch EcoModding Central 23 05-26-2019 05:41 AM
Winter cold start & idling warm-up experiment MetroMPG Hypermiling / EcoDriver's Ed 17 12-17-2010 03:39 PM
It's not just the A/C tasdrouille General Efficiency Discussion 4 04-17-2008 11:57 PM
Riding in cold weather, HELP! NoCO2 Alternative Transportation 16 03-20-2008 11:58 PM
MetroMPG.com mailbag: Metro engine won't stay warm in super cold weather MetroMPG General Efficiency Discussion 13 02-01-2008 11:28 PM



Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com