Aircon Problem-OFW from KSA

**shadow** · January 24th, 2012 06:00 PM

Kailangan Si Enrile dito da thread

**Retz** · January 24th, 2012 06:06 PM

meron din aircon servicing ang jaka group of companies ni enrile.

**burjegol** · January 24th, 2012 06:26 PM

Originally Posted by shadow

Kailangan Si Enrile dito da thread

si Enrile ang presiding si miriam ang investigator? ha-ha-ha. just kidding

**jick.cejoco** · January 24th, 2012 10:10 PM

Originally Posted by burjegol

got to clear somethings about the facts you have stated.

1. could you elaborate what you mean by an accumulator/dryer and receiver/dryer? In my 30 years as an practicing HVAC engineer, i haven't heard this terminology. an accumulator is a big different from a dryer and from a liquid receiver.

2. Likewise sight glass is usually installed in the liquid side to monitor the refrigerant state. I have encountered a sight glass which is connected to the suction side but it was to monitor the oil return to the compressor. The vision of the sight glass in the suction side as you mentioned will be cloudy, Of course as you are viewing the vapor state of the refrigerant. since it is colorless, the probable medium you are seeing the oil entrained in the refrigerant. If the sight glass is installed in the liquid line, you will view a clear sight glass when refrigerant quantity is correct, in accordance to its operating pressure.

3. fixed orifice and variable orifice? what controls the variable orifice to open and close to regulate the flow of refrigerant? Or you just simply means capillary expansion device (fixed orifice) or thermostatic expansion valve (variable orifice) ?

4. the low side varies from 27 to 35 psig, at what rpm of the engine? and the setting of the low pressure switch to open at 27 psig is usually utilised in R-22 system. We are discussing about R-134 system.

in a mobile automotive airconditioning or climate control system, the refrigeration cycle is the same as that of of fixed airconditioning. however, there are differences in operating systems and controls. an automotive system, the compressor speed varies with the driver's throttling the engine compared to a fixed speed of an HVAC. in an automobile system, the orifice tube type dryer is installed on the low side, does not need a sight glass and is a dyer at the same time. it is in the low side to prevent any liquid refrigerant that may have passed through the evaporator to prevent slugging the compressor. in a thermostatic expansion valve, the dryer is in the discharge side and is called a receiver. please do not confuse your fixed HVAC terminology with the automotive terms. i respect your being an HVAC engineer. in this field, i have been diagnosing, maintaining and repairing automotive systems for over thirty years. i have been teaching automotive service technology for over twenty years concurrently. i do not design them.

in an orifice tube system, both fixed and variable orifice tube type, so far from the big three namely ford (lincoln, mercury), chrysler (dodge, jeep) and GM (buick, cadillac, chevrolet, gmc, oldsmobile and pontiac) do not use sight glass.

what controls the variable orifice tube to modulate the opening? it is the temperature sensitive element inside the orifice tube working exactly like the capillary expansion valve. the fixed orifice is just a restriction to allow the liquid refrigerant to change in state.

the low or suction side varies from 27 psig to around 35 psig and still work satisfactorily even at idle speed. if the speed of the compressor overwhelms the flow control and the pressure drops below the 27 psig threshold, the compressor disengages to prevent the hose from collapsing and prevent freezing the evaporator. let's not talk about other refrigerant. we are talking about a vehicle that utilizes R134a for refrigerant, to be specific, we are talking about a GM product. as you have stated in previous posts, you said once the gauges are connected on the low side, it should read 110 psig. if the compressor was at rest, the pressure between the suction and the discharge is the same, but when you say the low side should read 110 psig, you are insinuating that the system is running. at that pressure of 110 psig, the temperature on your low side is 92.99 degrees fahrenheit. please check your pressure temperature chart, yes for R134a

**canproauto** · January 24th, 2012 10:41 PM

to TS , kung malapit ka po sa Las Pinas pwede natin i diagnose yung AC problem mo .

name ng shop namin CAN-PRO AUTO SPECIALIST 0999 991 7924

fully equipped po tayo w/ electronic leak detector , AC service station, snap on scanner , and service manuals.

**burjegol** · January 25th, 2012 01:28 AM

1. OK in the automotive, the filter drier is also a receiver. Just wondering then where will they put the desiccant though. In the fixed HVAC system, the liquid receiver is used to receive the liquid refrigerant when you are pumping down the system for repairs. So I think to call that small filter with sight glass installed in the liquid line of your automotive air conditioning system is misnomer.

2. Now, we come to the refrigerant flow regulator. You stated that in the variable orifice tube, it is controlled by a temperature sensing device, meaning a feeler bulb? well, if this is so, that means you are regulating the flow by controlling the orifice opening which is in turn controlled by a sensing bulb. this is the principle of operation of the expansion valve. In the fixed orifice, you said it is just a restriction for the liquid refrigerant. Have you noticed the capillary tube? and by the way, the refrigerant flow controls fixed or variable opening, does not change the state of the refrigerant. It expands them hence the term, "adiabatic expansion".

3. again you have stated the suction pressure of 27 to 35 psig. I am asking at what rpm of the engine should yo base this reading since this is a very big different from our fixed HVAC system you mentioned. and by the way, I also operate, repair and maintain open type compressor system wherein the compressor is driver by belts just like in the automotive system. the only difference is that, the rpm is somewhat constant and the compressor has various unloader system.

And I do not insinuate that the engine is running when I mentioned that when I attach the gauges, the readings is such. Now, question to you. when you attach the gauges to their respective ports, is the engine running or not? That is why I am asking the guy to indicate the rpm since he did not mentioned it likewise to you.

Now, this is an open exchange of ideas wherein we may learn from each other. You are an expert in your trade I presume, so let's learn together. I nearly have the experience to be a trainor in HVAC system in ARAMCO ITC but I declined the offer. You, on the other hand, is an experienced teacher.

**chua_riwap** · January 25th, 2012 01:52 AM

Originally Posted by burjegol

si Enrile ang presiding si miriam ang investigator? ha-ha-ha. just kidding

langya, pagalingan sa oral arguments........

(nosebleed!)

**burjegol** · January 25th, 2012 02:11 AM

1. OK in the automotive, the filter drier is also a receiver. Just wondering then where will they put the desiccant though. In the fixed HVAC system, the liquid receiver is used to receive the liquid refrigerant when you are pumping down the system for repairs. So I think to call that small filter with sight glass installed in the liquid line of your automotive air conditioning system receiver is misnomer.

2. Now, we come to the refrigerant flow regulator. You stated that in the variable orifice tube, it is controlled by a temperature sensing device, meaning a feeler bulb? well, if this is so, that means you are regulating the flow by controlling the orifice opening which is in turn controlled by a sensing bulb. this is the principle of operation of the expansion valve. In the fixed orifice, you said it is just a restriction for the liquid refrigerant. Have you noticed the capillary tube? and by the way, the refrigerant flow controls fixed or variable opening, does not change the state of the refrigerant. It expands them hence the term, "adiabatic expansion". The devices that changes the state of the refrigerant are the evaporator and condenser

3. again you have stated the suction pressure of 27 to 35 psig. I am asking at what rpm of the engine should yo base this reading since this is a very big different from our fixed HVAC system you mentioned. Likewise, what should the reading be when the engine is at idle? and by the way, I also operate, repair and maintain open type compressor system wherein the compressor is driver by belts just like in the automotive system. the only difference is that, the rpm is somewhat constant (depending on the power supply and power factor) and the compressor has various unloader system.

And I do not insinuate that the engine is running when I mentioned that when I attach the gauges, the readings is such. Now, question to you. when you attach the gauges to their respective ports, is the engine running or not? That is why I am asking the guy to indicate the rpm since he did not mentioned it likewise to you.

Now, this is an open exchange of ideas wherein we may learn from each other. You are an expert in your trade I presume, so let's learn together. I nearly have the experience to be a trainor in HVAC system in ARAMCO ITC but I declined the offer. You, on the other hand, is an experienced teacher.