Hello, I am new to the forum. I am a student at Wichita Area Technical College, and I am en route to obtain my AAS in HVACR. I just started my refrigeration classes and I am beginning to learn some of the lingo.
Anyways, I have a question regarding my home AC system.
I have a Goodman condensing unit, and a Trane furnace. I was outside the other day and I noticed the line running from my condensing unit to my furnace/ evaporator has water condensing on it. The water is seeping through the thick insulation on the line and there is some dripping near the furnace and some dripping outside by the condensing unit. My question is, is this normal, should I be concerned? What does this tell me?
it would be normal for water to condense on the cold lines coming back from the evaporator. That's the main reason it's insulated. Ideally, the insulation should be sealing the moist air out - that appears to not be the case. There will pretty much always be some condensation going on on the short exposed sections of tubing near the valves though.
If it is the "suction" line (i.e. the "fat" line) that is condensing, that is normal. The insulation is supposed to prevent that, but with age and sun damage the insulation often does not perform its intended job. I would not worry about it too much, but you can secure or replace the insulation if you like to get that extra .0005% of efficiency out of the system.
By the furnace where it is leaking, just wrap cork tape making sure to get it as tight as possible against the coil box. That should stop water drip inside.On the outside as long as the water is not dripping on anything that will cause damage. I would not worry to much about it. If you do reinsulate just remember to leave enough room to get a clamp style temp probe on it to check super heat. That is a term you should learn real good. It will help you diagnose multiple problems. Sub cooling is just as important.
By the furnace where it is leaking, just wrap cork tape making sure to get it as tight as possible against the coil box. That should stop water drip inside.On the outside as long as the water is not dripping on anything that will cause damage. I would not worry to much about it. If you do reinsulate just remember to leave enough room to get a clamp style temp probe on it to check super heat. That is a term you should learn real good. It will help you diagnose multiple problems. Sub cooling is just as important.
Good idea! We have already touched on the superheat and subcooling and how it applies to the refrigeration cycle, but I'm still a little fuzzy on it. I just need to go over my notes. Today I learned how to read a Pressure Enthalpy chart and that was pretty cool. I like graphs. lol
Good idea! We have already touched on the superheat and subcooling and how it applies to the refrigeration cycle, but I'm still a little fuzzy on it. I just need to go over my notes. Today I learned how to read a Pressure Enthalpy chart and that was pretty cool. I like graphs. lol
Superheat: The heat added to a vapor beyond its saturation temperature. For purposes of refrigeration if you look on your gauges, there is a temperature scale that corresponds to the pressure. That is the saturation temperature of the refrigerant. So if you are at a pressure where the saturation temperature is 40 degrees Fahrenheit and the suction line is 52 degrees then you have 12 degrees of superheat. Steam heated above 212 degrees would be superheated. The air we breathe is superheated.
Subcooling: Heat removed from a liquid below its saturation point. Again, for purposes of refrigeration if the high side of the system is operating at 205psi that corresponds to a 100 degree saturation temperature (R-22). If the temperature of the liquid line leaving the condenser is 88 degrees that would be a 12 degree subcooling. Everything we drink, water; beer; soda; ect is a subcooled liquid.
Saturation temperature: The temperature where a state change occurs from liquid to gas or from gas back to liquid again. Saturation temperature refers to both evaporation and condensation and so it applies to both the vapor and liquid portions of the refrigerant cycle.
If you learn and truely understand these principles then you will be well ahead of the curve in the HVAC-R industry. Shamefully, many contemporaries in this field do not fully understand how a vapor compression refrigeration cycle works. Their lack of knoweledge harms the reputation of the industry as a whole, but provides a bona-fide opportunity for those that do understand and can offer real solutions to intricate problems to their customers.
Superheat: The heat added to a vapor beyond its saturation temperature. For purposes of refrigeration if you look on your gauges, there is a temperature scale that corresponds to the pressure. That is the saturation temperature of the refrigerant. So if you are at a pressure where the saturation temperature is 40 degrees Fahrenheit and the suction line is 52 degrees then you have 12 degrees of superheat. Steam heated above 212 degrees would be superheated. The air we breathe is superheated.
Subcooling: Heat removed from a liquid below its saturation point. Again, for purposes of refrigeration if the high side of the system is operating at 205psi that corresponds to a 100 degree saturation temperature (R-22). If the temperature of the liquid line leaving the condenser is 88 degrees that would be a 12 degree subcooling. Everything we drink, water; beer; soda; ect is a subcooled liquid.
Saturation temperature: The temperature where a state change occurs from liquid to gas or from gas back to liquid again. Saturation temperature refers to both evaporation and condensation and so it applies to both the vapor and liquid portions of the refrigerant cycle.
If you learn and truely understand these principles then you will be well ahead of the curve in the HVAC-R industry. Shamefully, many contemporaries in this field do not fully understand how a vapor compression refrigeration cycle works. Their lack of knoweledge harms the reputation of the industry as a whole, but provides a bona-fide opportunity for those that do understand and can offer real solutions to intricate problems to their customers.
I hope this helps, and good luck with school.
Thanks for the clarification!
If I have this right, a saturated gas would be 100% gas that has just absorbed all of the latent heat necessary to change from a liquid, but once the saturated gas begins absorbing sensible heat, the gas becomes superheated?
...If I have this right, a saturated gas would be 100% gas that has just absorbed all of the latent heat necessary to change from a liquid, but once the saturated gas begins absorbing sensible heat, the gas becomes superheated?
Definition: Saturated Gas is a vapor in stable equilibrium contact with its own liquid.
(This can be static, as in a refrigerant drum, or dynamic as in the condenser or evaporator, typically after about 10 or 15 minutes of operation. Adding heat causes evaporation of a portion of liquid and removing heat causes condensation of a portion of the vapor.)
Definition: Saturated Gas is a vapor in stable equilibrium contact with its own liquid.
(This can be static, as in a refrigerant drum, or dynamic as in the condenser or evaporator, typically after about 10 or 15 minutes of operation. Adding heat causes evaporation of a portion of liquid and removing heat causes condensation of a portion of the vapor.)
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Originally Posted by meoberry
