DIY - Cooler AirCon for FREE

[jin1119]

True. If liquid goes into the compressor it would spoil. Therefore the refrigerant goes into the compressor as saturated vapour. That is why never set your thermostat to the lowest temp. if the load in space is low, e.g. rainy day or in the morning. So make sure the temperature at suction is not lower than approx -9.4 deg C.

Second thing: higher suction temperature back to compressor does not reduce compressor work but increase it. Very simple question: Why does the compressor needs to work harder when the heat inside a room is high? When the load in suction is high, that means the compressor has to give higher refrigerant flow rate in order to dissipate enough heat at the condensing side so that it can obtain 12~15 deg C at the evaporator coil.

COP of the system is Heat/Work (Q/W). The higher the Q, the lower the COP.

Our evaporator now day come with electronic expansion valve where is can control the liquid refrigerant flow in to the system depend on heat load in the cabin. it will control the right quantity amount of liquid flow in to evaporator and make sure all the liquid fully vaporize at the evaporator outlet.

it depend on many condition, says your compressor,

SST (saturate suction temperature) is 4degC
SDT (saturated discharge temperature) is 50degC
delta T is about 46degC, meaning to say compressor need to compress from 4degC to 50degC to condenser coil to get heat rejection.

Lower the SST will push the compressor to work more.
if let say you have superheating about 1degC mean your SST will be 4+1degC, hence delta T 50-(4+1)=45degC
It reduce the compression ratio between SDT and SST.

 

[Supra_Fanatics]

True. If liquid goes into the compressor it would spoil. Therefore the refrigerant goes into the compressor as saturated vapour. That is why never set your thermostat to the lowest temp. if the load in space is low, e.g. rainy day or in the morning. So make sure the temperature at suction is not lower than approx -9.4 deg C.

Second thing: higher suction temperature back to compressor does not reduce compressor work but increase it. Very simple question: Why does the compressor needs to work harder when the heat inside a room is high? When the load in suction is high, that means the compressor has to give higher refrigerant flow rate in order to dissipate enough heat at the condensing side so that it can obtain 12~15 deg C at the evaporator coil.

COP of the system is Heat/Work (Q/W). The higher the Q, the lower the COP.

So actually is good to actually wrap the hotter pipe line as well?

 

[cvkit17]

Our evaporator now day come with electronic expansion valve where is can control the liquid refrigerant flow in to the system depend on heat load in the cabin. it will control the right quantity amount of liquid flow in to evaporator and make sure all the liquid fully vaporize at the evaporator outlet.

it depend on many condition, says your compressor,

SST (saturate suction temperature) is 4degC
SDT (saturated discharge temperature) is 50degC
delta T is about 46degC, meaning to say compressor need to compress from 4degC to 50degC to condenser coil to get heat rejection.

Lower the SST will push the compressor to work more.
if let say you have superheating about 1degC mean your SST will be 4+1degC, hence delta T 50-(4+1)=45degC
It reduce the compression ratio between SDT and SST.

You seem to know thermodynamics
But before replying to your opinion, I would like to clarify with you:

1. The thermal expansion device is a throttle controller which controls the refrigerant flow?
2. Is it the more the refrigerant superheat, the less power the compressor consumes? E.g the AC consume less energy in a hot room than a cold room.

So actually is good to actually wrap the hotter pipe line as well?

Not necessarily. It depends on the surrounding temperature of the hot pipe. If the surrounding temp is a lot higher than the temp of the hot pipe, then it is better to insulate it. If it is not, then don't insulate.

 

[jin1119]

You seem to know thermodynamics
But before replying to your opinion, I would like to clarify with you:

1. The thermal expansion device is a throttle controller which controls the refrigerant flow?
2. Is it the more the refrigerant superheat, the less power the compressor consumes? E.g the AC consume less energy in a hot room than a cold room.



Not necessarily. It depends on the surrounding temperature of the hot pipe. If the surrounding temp is a lot higher than the temp of the hot pipe, then it is better to insulate it. If it is not, then don't insulate.

Just sharing some what i know.
expansion valve basically got 2 major function, one is to expand those refrigerant in to low pressure (low pressure = low temperature)before going in to evaporator for cooling effect, another one is to control the total amount for liquid flowing in to evaporator base on cabin heat load.

cant say higher superheat lesser cmpressor load. we must know the delta T between high side and low side difference, higher the difference higher work compressor to do, cause compressor need to compress those gas to higher temperature to condenser for heat rejection effect as our country ambient temperature is quite high.

if ambient temperature is low meaning you will have better heat rejection and of cause air cond will perform better, in this case your high side temp also low and compressor compression ratio lower, compressor has less work, better refrigeration effect.

 

[twistedichc]

:wavey:question?? reading the wiki, I assume that, in a car, compressor work is to make the refrigerant that is already hot super hotter before getting into the condender to dissipate heat & to reliquidify the gas with lower temperature right. than the valve releases required amount of liquid into the evaporator to collect the heat from inside cabin & become gas again. am I right??

 

[stupidcar]

Man, I'm too dumb for this.

 

[vr2turbo]

Man, I'm too dumb for this.

Not only you. I also know the basic only. Only bro. cvkit and jin1119 are the professors in this....

 

[twistedichc]

Not only you. I also know the basic only. Only bro. cvkit and jin1119 are the professors in this....

yepp they surely r, I oni got to know the parts names oni coz basically changed every part for my fish & the AC doesn't last oso. things I've changed the cost is more than buying new ori compressor edi.

 

[cvkit17]

Just sharing some what i know.
expansion valve basically got 2 major function, one is to expand those refrigerant in to low pressure (low pressure = low temperature)before going in to evaporator for cooling effect, another one is to control the total amount for liquid flowing in to evaporator base on cabin heat load.

cant say higher superheat lesser cmpressor load. we must know the delta T between high side and low side difference, higher the difference higher work compressor to do, cause compressor need to compress those gas to higher temperature to condenser for heat rejection effect as our country ambient temperature is quite high.

if ambient temperature is low meaning you will have better heat rejection and of cause air cond will perform better, in this case your high side temp also low and compressor compression ratio lower, compressor has less work, better refrigeration effect.

Agree on the TXV and ambient temperature but I have not come across the delta T thingy before. I only know delta T between evaporator and condenser lol

Well 2 things you must know..first law of thermo and PH diagram. Heat absorbed needs to be rejected somehow and PH diagram can shows why.

It's lucky for me to be able to find a good article from google so that I don't have to type a lot LOL.

Ice Breaker: Suction Line Insulation | 2013-09-02 | ACHRNEWS

Happy reading =)

Ohya, insulating the suction line is way more important than the hot line. So SF, insulate the suction line first and then only use the rest for others.

:wavey:question?? reading the wiki, I assume that, in a car, compressor work is to make the refrigerant that is already hot super hotter before getting into the condender to dissipate heat & to reliquidify the gas with lower temperature right. than the valve releases required amount of liquid into the evaporator to collect the heat from inside cabin & become gas again. am I right??

The refrigerant coming out from evaporator is cold to us, but scientifically hot haha. You are right.

 

[vr2turbo]

Agree on the TXV and ambient temperature but I have not come across the delta T thingy before. I only know delta T between evaporator and condenser lol

Well 2 things you must know..first law of thermo and PH diagram. Heat absorbed needs to be rejected somehow and PH diagram can shows why.

It's lucky for me to be able to find a good article from google so that I don't have to type a lot LOL.

Ice Breaker: Suction Line Insulation | 2013-09-02 | ACHRNEWS

Happy reading =)

Ohya, insulating the suction line is way more important than the hot line. So SF, insulate the suction line first and then only use the rest for others.



The refrigerant coming out from evaporator is cold to us, but scientifically hot haha. You are right.

Good article but to layman like us still understand slightly only.....

 

[cvkit17]

Good article but to layman like use still understand slightly only.....

Haha..very simple. The enthalpy is energy (which is the x-axis in the graph). So if heat goes into the refrigerant in the evaporator, enthalpy is increased. We call it superheat. At condenser side we call it sub cooling (reject heat).

 

[twistedichc]

so that means, insulate the line going to compressor is better coz reducing the risk of overheating the compressor for better performance, so the best way to improve performance of our AC is to insulate all so it runs under its circulation temp with lesser interference from outer temp. correct me if i am wrong sifuses


wifey lenovo wit tapatalk

 

[cvkit17]

so that means, insulate the line going to compressor is better coz reducing the risk of overheating the compressor for better performance, so the best way to improve performance of our AC is to insulate all so it runs under its circulation temp with lesser interference from outer temp. correct me if i am wrong sifuses


wifey lenovo wit tapatalk

You hit the spot! But insulating cold side has more effect than insulating the hot side

 

[twistedichc]

so that the coldness of the refrigerent does not affected by the ambient temp rite?

wifey lenovo wit tapatalk

 

[cvkit17]

so that the coldness of the refrigerent does not affected by the ambient temp rite?

wifey lenovo wit tapatalk

Yes. The suction line is kind of part of the evaporator. If heat is gained that means the load is high

 

[Supra_Fanatics]

You hit the spot! But insulating cold side has more effect than insulating the hot side

Like Vr2turbo told me yesterday. If the hot pipe is hot enough best to leave it. Unless is not hot enough the insulaflex will help. Cuz if it is very hot, if insulate, the temp would be trap inside and containing the heat inside and the heat cant disperse easily if were to compared with hot pipe unwrap right?

 

[Izso]

fark.. so do I wrap everything or not?

 

[cvkit17]

Like Vr2turbo told me yesterday. If the hot pipe is hot enough best to leave it. Unless is not hot enough the insulaflex will help. Cuz if it is very hot, if insulate, the temp would be trap inside and containing the heat inside and the heat cant disperse easily if were to compared with hot pipe unwrap right?

fark.. so do I wrap everything or not?

Wrap the suction line first.. Then if got extra, wrap the suction line of your other cars. If after that you still have extra then only wrap the hot line. No harm wrapping the hot line, just that it is not as good as wrapping the cold line.

 

[vr2turbo]

Wrap the suction line first.. Then if got extra, wrap the suction line of your other cars. If after that you still have extra then only wrap the hot line. No harm wrapping the hot line, just that it is not as good as wrapping the cold line.

But after wrapping and not enough you know who to look for......hahahhahahahhaha

 

[Supra_Fanatics]

Wrap the suction line first.. Then if got extra, wrap the suction line of your other cars. If after that you still have extra then only wrap the hot line. No harm wrapping the hot line, just that it is not as good as wrapping the cold line.

But after wrapping and not enough you know who to look for......hahahhahahahhaha

Mine 1 piece enough for 1 Kelisa and Kancil

Anyway, sharing my part. Mind the poor quality of photos...Cartel phones is not much to offer.







This was easier to be done, compared to my mousedeer which the cold pipeline is just too close to the chassis wall. Struggled longer than having it installed in my kelisa. Photos are kelisa.