dclark1946
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Re: A/C Condenser Evaporative Cooling Assist
PatJ wrote: I like the idea and would love anything that would make RV AC more effective or efficient, and wish you the best of luck overcoming the issues with using water to assist the condenser in an RV. In the meantime, it seems to me the effort is best spent just using a much larger condenser and much larger condenser fan for increased efficiency. Of course then we would need a variable speed condenser fan and compressor to keep the pressures in check, maybe an electronic TXV, and a computer to run the whole thing. This is starting to sound like a modern mini-split!. Most current RV roof air conditioners use 1960s/1970s window banger technology. They could make a rooftop RV air conditioner with a very superior performance and efficiency to what's available now, but it would be $4500 instead of $800. You and I may buy one for that, but unfortunately we are the minority RV buyer at the moment. We do have the Coleman Mach 3 PS 13.5 which has a higher efficiency compressor (scroll I think) and larger condenser compared to their standard 13.5 Mach 3. Currently only have 15A service in our back yard where our trailer is parked and that works well except in the middle 9f Aug. in full sunlight.1.2KViews0likes0CommentsRe: A/C Condenser Evaporative Cooling Assist
PatJ wrote: I like the idea and would love anything that would make RV AC more effective or efficient, and wish you the best of luck overcoming the issues with using water to assist the condenser in an RV. In the meantime, it seems to me the effort is best spent just using a much larger condenser and much larger condenser fan for increased efficiency. Of course then we would need a variable speed condenser fan and compressor to keep the pressures in check, maybe an electronic TXV, and a computer to run the whole thing. This is starting to sound like a modern mini-split!. Most current RV roof air conditioners use 1960s/1970s window banger technology. They could make a rooftop RV air conditioner with a very superior performance and efficiency to what's available now, but it would be $4500 instead of $800. You and I may buy one for that, but unfortunately we are the minority RV buyer at the moment. We do have the Coleman Mach 3 PS 13.5 which has a higher efficiency compressor (scroll I think) and larger condenser compared to their standard 13.5 Mach 3. Currently only have 15A service in our back yard where our trailer is parked and that works well except in the middle 9f Aug. in full sunlight.1.2KViews0likes0CommentsRe: A/C Condenser Evaporative Cooling Assist
pianotuna wrote: dclark1946 wrote: I don't understand how any kind of evaporative cooler can function to lower temperature in a closed environment regardless of where it is located. The cooling process adds moisture to the air raising the interior humidity and if it is just recirculating it keeps adding more humidity to the air reducing the cooling. To me it seems somewhat similar to operating a window A/C unit totally inside your closed RV with the cooled evaporator air and heated condenser air both being blown into your RV. Then you don't understand that when water evaporates the temperature is lowered. It is NOT at all similar to a window A/C operating inside. I must be doing a terrible job of communicating on this post. I was trying to use an analogy with the window unit substituting temperature for humidity. I fully understand that when water evaporates the air is cooled. The lower the relative humidity the greater the cooling. I used that principle in the A/C assist evaporative cooler I designed, built and used successfully for years. However when the air is cooled by evaporation the air moisture content is increased. If you keep recycling the air through the evaporative cooler in a closed environment (no outside air brought in) the relative humidity will continue to increase and the evaporation process will give you less and less cooling. I hope I have explained it clearly.1.2KViews0likes0CommentsRe: A/C Condenser Evaporative Cooling Assist
Chum lee, I get it that you understand the technical concept of evaporative cooling to assist the A/C by significantly reducing condenser temperature. Your responses however seem to suggest that this is an impractical solution looking for a suitable problem. I have already demonstrated to myself how well it works on a home residential system under extreme temp conditions. I would agree that under normal camping conditions there is no need to assist an RV A/C. It is the extreme high ambient temperature conditions that I routinely run into every year (as do others camping in Jul/ Aug here in TX) where the heat load exceeds the A/C BTU capacity (which unfortunately is decreasing as temps go above 95) that would benefit.1.2KViews0likes0CommentsRe: A/C Condenser Evaporative Cooling Assist
pianotuna wrote: dclark1946 wrote: I thought you were referring to the rooftop RV evaporative cooler where you would keep a window open for proper operation. The reason your cooler did not work is because it kept raising the interior humidity level to the point that very little evaporative cooling could occur. These coolers only work when you have a continued fresh supply of outside air. I'm aware of the need to have a way to exhaust air when running a roof top evaporative cooler. The input air was at 27 C, the output air was about 4 C cooler, at 23 C. The physical temperature in the RV rose as the out door temperature peaked at 31 C. I did take humidity readings--but I failed to record them. I'm comfortable up to 25 c (77 f). The recirculating air evaporative cooler I purchased was not able to maintain the RV at 25 C, even though the makers rating was for 500 square feet when my RV is 241 square feet. I don't understand how any kind of evaporative cooler can function to lower temperature in a closed environment regardless of where it is located. The cooling process adds moisture to the air raising the interior humidity and if it is just recirculating it keeps adding more humidity to the air reducing the cooling. To me it seems somewhat similar to operating a window A/C unit totally inside your closed RV with the cooled evaporator air and heated condenser air both being blown into your RV. Except in this case you would dehumidfy the air but not see any net cooling because the heat you absorbed in the A/C evaporator would be pumped right back into the RV via the condenser.1.2KViews0likes0CommentsRe: A/C Condenser Evaporative Cooling Assist
pianotuna wrote: dclark1946 wrote: pianotuna wrote: Chum lee, Where I live--I do on occasion run a humidifier in my RV. But never in the summer. Our relative humidity goes from 4% to 84% on a yearly basis. Even with our relatively low humidity I found the swamp cooler I bought, rated for 500 square feet, did just about nothing for the 241 square feet in my class C. Here is the one I was referencing: https://www.turbokool.net/product-p/2b-0001-turbokool-swamp-cooler.htm They don't share the picture--how odd of them. Did you open a window to allow the outside air pulled into the evaporative cooler to push the trailer air outside? These systems are commonly used for interior cooling in dry climates where the cooling is greater and increase in interior humidity is a desired benefit. We used evaporative cooling in Dallas when I was a kid with cooler pads in three windows and a centrally located attic fan that pulled outside air through the wet pads and exhausted interior air out through the attic. Hi, The unit I purchased is a "stand alone" device that recirculates the air in the room. It did lower the temperature of the out put air--but there was too little cooling going on to keep up with the sun--even thought I had purchased something that was supposed to be good for double the area I was attempting to cool. I thought you were referring to the rooftop RV evaporative cooler where you would keep a window open for proper operation. The reason your cooler did not work is because it kept raising the interior humidity level to the point that very little evaporative cooling could occur. These coolers only work when you have a continued fresh supply of outside air.244Views0likes0CommentsRe: A/C Condenser Evaporative Cooling Assist
Chum lee wrote: dclark1946 wrote: Chum lee, The evaporative cooling system I am proposing raises the humdity only of the outside air passing through the condenser unless the RV A/C is not sealed properly and allows leakage between outside and interior (conditioned) air. It should function like the home central A/C system I referred to in my original post. Not only does the humidified cooled air benefit the condenser because of the lower temperature but the denser humid cool air is more efficient in removing heat from the condenser coils. I understand what you are doing and I agree with you. It will work. However, how much time have you spent traveling/living in an RV? Most who have realize that water is always at a premium when they are out and about. (boondocking/camping/fishing/hunting/etc.) If you prefer to stay in an RV park, generally, water/electricity/sewage are no big deal. IMO, you are trying to solve a problem that doesn't exist. I don't know what else to say to you other than "live and learn." Chum lee Apparently you have not comprehended my posts with regard to where I would use the A/C assist. I listed two different specific scenarios at home where this would be most beneficial for us. We have been camping in travel trailers since 1999 and have traveled thousands of miles. We typically do not camp at locations where the daytime temperature is expected to be above mid 90's although we often stay at a commercial campground overnight (where there have been upper 90 deg daytime temps ) heading to a cooler more scenic final destination where we will dry camp and not require A/C. However on a North Texas RV website there have been multiple posts by those trying to camp in recent NT 100+ deg weather who find their RV A/C is not up to the task of maintaining comfortable temp. I think these campers might also benefit from such a system and since they are camping mostly either in state parks or commercial camp grounds water supply should not be an issue.245Views0likes0CommentsRe: A/C Condenser Evaporative Cooling Assist
pianotuna wrote: Chum lee, Where I live--I do on occasion run a humidifier in my RV. But never in the summer. Our relative humidity goes from 4% to 84% on a yearly basis. Even with our relatively low humidity I found the swamp cooler I bought, rated for 500 square feet, did just about nothing for the 241 square feet in my class C. Here is the one I was referencing: https://www.turbokool.net/product-p/2b-0001-turbokool-swamp-cooler.htm They don't share the picture--how odd of them. Did you open a window to allow the outside air pulled into the evaporative cooler to push the trailer air outside? These systems are commonly used for interior cooling in dry climates where the cooling is greater and increase in interior humidity is a desired benefit. We used evaporative cooling in Dallas when I was a kid with cooler pads in three windows and a centrally located attic fan that pulled outside air through the wet pads and exhausted interior air out through the attic.244Views0likes0CommentsRe: A/C Condenser Evaporative Cooling Assist
Chum lee, The evaporative cooling system I am proposing raises the humdity only of the outside air passing through the condenser unless the RV A/C is not sealed properly and allows leakage between outside and interior (conditioned) air. It should function like the home central A/C system I referred to in my original post. Not only does the humidified cooled air benefit the condenser because of the lower temperature but the denser humid cool air is more efficient in removing heat from the condenser coils.245Views0likes0Comments
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