To increase the AC efficiency

[nissanh]

I don't know why Toyota didn't insulate the AC suction line between the firewall and compressor: So I did it!

Atmospheric water vapor condenses on this hose: Any condensation means for the system which is freon, a gain of energy (can also be called heat) from water vapor. This heat adds to the heat generated during the compression of freon.

One more helpful hint for home AC users: The capacitor on my home AC got blown at 4:30 PM and glad I was able to find one before 5 PM, and installed it by my self. What I've been told is to keep a spare capacitor handy. A capacitor sells online for less than $30 so keep one ready! Buy capacitor based on the micro Faraday value posted.

 

[eddielasvegas]

Thanks for the auto and residential HVAC info and reminder.

My former HVAC company wanted to charge me $650 to replace the capacitors (2) in our units. Said they were bad. I declined knowing they were $30 parts and had them checked by a trusted HVAC tech. No issues and just a money grab by this unscrupulous company.


Any idea what increase in efficiency adding the insulation will create?


Eddie

 

[audiness]

Looks like it will help. Also get some coil cleaner and clean your condenser

 

[JRZEE2000TR4LTD]

I don't know why Toyota didn't insulate the AC suction line between the firewall and compressor: So I did it!

Atmospheric water vapor condenses on this hose: Any condensation means for the system which is freon, a gain of energy (can also be called heat) from water vapor. This heat adds to the heat generated during the compression of freon.

One more helpful hint for home AC users: The capacitor on my home AC got blown at 4:30 PM and glad I was able to find one before 5 PM, and installed it by my self. What I've been told is to keep a spare capacitor handy. A capacitor sells online for less than $30 so keep one ready! Buy capacitor based on the micro Faraday value posted.

Shouldn't need to insulate that line. It is the suction line post evaporator to the compressor. You want low pressure gas - vapor - in this line as that is what the compressor wants - vapor. By insulating it you may lower the temp of the gas and it may liquefy a little and make your compressor unhappy.

The unit for capacitors is farads.
Keep an eye on that compressor too. Usually when those caps go on the single-phase motors or compressors it means they they were overloaded by a restriction mechanically. Not in all cases, but I know just about every motor I replaced caps on I had to go back to and replace the entire motor. Check the start and run amps and see if it's close to the load rating.

 

[jgue467]

Shouldn't need to insulate that line. ...

+1. Toyota is Not dumb and engineered it that way.

Now here was my thought. My a/c is beyond belief COLD as is (dirty with very little maintenance other than one item described below)! After 15 mins of cooling a closed (hours long) in central texas 105+ temps, I have to turn fan speed down, redirect "crotch" cooler vent and so forth.

It doesn't need to be more efficient.

Now here is what I think many, many folks over look in a/c maintenance, the space between the condensor and radiator. Remove the skid pan and take a good look up between the two. That is where debris, grass and such begin to block the flow of air which is what both depend on.

I'd like to clean my evaporator, I'm sure it's never been opened and has to be horribly dirty yet the SOB is beyond belief cold as it, should I bother?

Luck and enjoy those Runners. :cowboy:

 

[nissanh]

Reply

Thanks for the auto and residential HVAC info and reminder.

My former HVAC company wanted to charge me $650 to replace the capacitors (2) in our units. Said they were bad. I declined knowing they were $30 parts and had them checked by a trusted HVAC tech. No issues and just a money grab by this unscrupulous company.


Any idea what increase in efficiency adding the insulation will create?


Eddie

I am not sure about the exact quantity: About Chemistry-Physics: AC works on Joule Thompson effect and total enthalpy (or the internal energy) at the expansion valve is constant. Narrow tube (high side) becomes a wide tube at the expansion valve and the volume change is what brings the kinetic energy down making it cooler. Based on all that, I find cooler freon going into the compressor (1) helps to cool the compressor (2) lowers the output temperature on high side.

My 92 Corolla, 2000 Land cruiser got factory insulation on the suction hose all the way from firewall to the compressor.

If you look at your home AC, the return line is covered with an insulation as well.

I do clean all the condenser/radiator fins in my vehicles and home condenser prior to every summer.

I am more into efficiency, I guess!!!

 

[gamefreakgc]

That insulation is very close to your exhaust manifolds. Make sure they are not toching anything, not even the heat shield or it's going to be a sloppy, smelly mess on a long drive.

 

[PRG3K]

My system has had little to no maintenance, as far as I know, in 21 years. After 15 minutes in the Florida summer, the cabin is colder than a morgue. I have no idea how nasty the evaporator looks but the air doesn't even smell. Genius engineers were making these things.

 

[jgue467]

That insulation is very close to your exhaust manifolds. Make sure they are not toching anything, not even the heat shield or it's going to be a sloppy, smelly mess on a long drive.

Or worse, a fire, yikes! Perhaps a heat shield in more in order?? :cowboy:

 

[19963.4lsr5]

I vacuum my system and charged it after the engine swap. Charged it and my temp gun showed 28 to 35f on the center vent outlet. I am pretty sure our system has an orifice tube, which as the low pressure low temperature liquid from the condenser is forced through the hole it starts boiling off which absorbs heat and makes the cold air. Sometimes that length of tubing is designed to be an exact length to catch the “vapor” just as it enters the EVAP. Insulating it would keep it in liquid form longer and possibly lower the efficiency and heat absorption.

Just my 3 cents.....


Sent from my iPhone using Tapatalk

 

[JRZEE2000TR4LTD]

I vacuum my system and charged it after the engine swap. Charged it and my temp gun showed 28 to 35f on the center vent outlet. I am pretty sure our system has an orifice tube, which as the low pressure low temperature liquid from the condenser is forced through the hole it starts boiling off which absorbs heat and makes the cold air. Sometimes that length of tubing is designed to be an exact length to catch the “vapor” just as it enters the EVAP. Insulating it would keep it in liquid form longer and possibly lower the efficiency and heat absorption.

Just my 3 cents.....


Sent from my iPhone using Tapatalk

These systems use an expansion valve not an orifice tube.

High pressure liquid is what is what is fed through the expansion valve making it low pressure liquid allowing the refrigerant to be in it's coldest state and absorb the most heat as it passes through the evaporator

The line he insulated is the line AFTER the evaporator to the suction side of the compressor. Probably not going to hurt anything but IMHO really not going to help anything either as cold and efficient as these systems seem to be.

 

[96RedRunner]

Interesting topic, I'm in the group with design is a good one though experimenting is cool if hazards are not put into it.

Maint of system has been mentioned.
Easy way to get to Evap for cleaning is to remove the fan speed resistor module, gives you about a 2" x 4" opening to work with.
I learned the expensive way on this one, the drier 320k mi never changed it. Desiccant cartridge inside drier broke into zillion pieces, required replacing everything in system. A $30 part tuned into $1100.00 in parts PITA job, well worth changing drier around 300k mi. On my 01 I changed it at 200k along with condensor.

 

[Vooryjoni]

Recharge or new compressor

I recharged my A/C recently with that A/C Pro bottle. I think it is R134. It has a pressure gauge and tells me when it is filled. It was not blowing cold air and after it became much better.

If efficiency is the ultimate goal than get a high-end compressor as it will take less energy from the engine and cool the cabin better.

Good luck all.

 

[averyislost]

I agree, the AC in my 4runner has had zero maintenance as far as I know and it's crazy cold compared to even newer cars. Compared to my '15 Fiesta ST, it's a night/day difference. I can't think of another car I've been in recently where I get cold inside and have to turn up the temperature even when it's 100 degrees outside.

+1. Toyota is Not dumb and engineered it that way.

Now here was my thought. My a/c is beyond belief COLD as is (dirty with very little maintenance other than one item described below)! After 15 mins of cooling a closed (hours long) in central texas 105+ temps, I have to turn fan speed down, redirect "crotch" cooler vent and so forth.

It doesn't need to be more efficient.

Now here is what I think many, many folks over look in a/c maintenance, the space between the condensor and radiator. Remove the skid pan and take a good look up between the two. That is where debris, grass and such begin to block the flow of air which is what both depend on.

I'd like to clean my evaporator, I'm sure it's never been opened and has to be horribly dirty yet the SOB is beyond belief cold as it, should I bother?

Luck and enjoy those Runners. :cowboy: