tommie gorman Posted August 5, 2006 CID Share Posted August 5, 2006 justinlay, do you also have a basement? Quote Link to comment Share on other sites More sharing options...
cholla Posted August 5, 2006 CID Share Posted August 5, 2006 justinlay & anyone else I know Voltageman warned of this but I'm going to put it where it can't be missed. TURN OFF ALL ELECTRICITY TO THE UNIT BEFORE YOU WASH IT Quote Link to comment Share on other sites More sharing options...
justinlay Posted August 5, 2006 CID Share Posted August 5, 2006 my outside unit does say 4ton in it. no tommie i dont have a basement i have a moble home Edit: I did notice when i went outside i did notice the coils where dirty Quote Link to comment Share on other sites More sharing options...
tommie gorman Posted August 5, 2006 CID Share Posted August 5, 2006 4ton would be actually a little high for 1500sq feet. my place is 1475sq feet and mine is 2.5 ton. Not really dlewis23. I install 2.5 ton's in all of my 900sq. ft. rental houses with basements And have no trouble, except maintenence. "Change your furnace filters tenants, please!" 99% of the problems. "No airflow, no A/C!" And then I have to make sure the condensors are also clean. Quote Link to comment Share on other sites More sharing options...
Voltageman Posted August 5, 2006 CID Share Posted August 5, 2006 If it is a 2.5 ton then it might be a little too small. Interesting that oversizing will not cause ice up. & you say the air intake should basically be located high on the wall & not near a supply vent. Like I said for me where I live humidity is almost never a problem & I'm able to use a swamp cooler most of the time.My 2 refrigerated window units will do a pretty good job for the rare times humidity is high. Low humidity makes cooling very easy...The water is the problem. Water requires a lot of energy to heat...And it also requires a lot of energy to remove the heat...Less water = less energy required for cooling. And yes high returns are preferable, especially if you have floor grilles...If you have a low return and floor grilles, the air will sit at the floor, and just recycle, and not cool the house...Ceiling fans help alleviate this. Supplies too close to the return can increase the chances of freezing. Especially as house gets cooler. There is approx. a 20deg difference across an a/c coil. If you send say 70 deg air into return, you get around 50 deg out...So if you start sending 50 deg air into return, it gets cooler...And so on.. If return is say 60deg..it will drop to 40...which means coil is colder than that...Probably close to 32. Once it gets to 32, the water freezes on the coil, the pressure in unit drops even further, which makes coil even colder. And now the ice has covered coil, so no air flows...Even cooler...Now if unit is undercharged or dirty, this can happen pretty easy. Quote Link to comment Share on other sites More sharing options...
Voltageman Posted August 5, 2006 CID Share Posted August 5, 2006 General rule of thumb when sizing a/c is: 12,000btu = 1 ton = 400 square ft If you live in a very dry climate(low humidity), you will need less. my outside unit does say 4ton in it. no tommie i dont have a basement i have a moble home Edit: I did notice when i went outside i did notice the coils where dirty Clean them, and you will notice a difference.. Edit: Check your windows for leaks...If you find any, get the window sealer..3m makes good stuff... Feel the floor on a hot day...Is it warm? If trailer has space underneath it(open area) see if it gets warm...Perhaps the floor has poor insulation.. Quote Link to comment Share on other sites More sharing options...
tommie gorman Posted August 5, 2006 CID Share Posted August 5, 2006 I am not sure if this has been addressed, but you might have your freon checked. If it is low, have them fix the leaks. Even though it is fairly new, there are bad installs. Quote Link to comment Share on other sites More sharing options...
Voltageman Posted August 5, 2006 CID Share Posted August 5, 2006 Even though it is fairly new, there are bad installs. I've seen a bunch of em... It's amazing the crap work some people do...If they ever tell you you need refrigerant, tommie is correct, make them find the leak. Contrary to myth, refrigerant does not have to be changed/added. Oil is the only thing that may need to be changed, and this is normally only done with commercial units. Is your unit a packaged unit? Meaning one unit mounted on outside of trailer.... Quote Link to comment Share on other sites More sharing options...
tommie gorman Posted August 5, 2006 CID Share Posted August 5, 2006 Actually justinlay, you can do a partial test yourself, just fill up a bottle with soapy water (like an empty window cleaner bottle)and spray it on the soldered joints on the line. It will foam up if you do have leaks. But this will not tell you if you have any leaks in the A coil inside the furnace. Quote Link to comment Share on other sites More sharing options...
cholla Posted August 5, 2006 CID Share Posted August 5, 2006 If you can, take door off unit in attic(the door where the pipes go in..either 5/16 or 1/4" nut driver will do), and take a look at the coil. It could just be dirty.....Make sure they didn't leave the factory filter in the unit(will be right after where the return ductwork is attached...I've seen it left in, and people don't know about it, and only change filter in the grille...Over time, that second filter will get plugged, and decrease cooling capacity. Voltageman ;I wanted to know more about the underlined part.Should this filter be replaced if it is there or just removed? Quote Link to comment Share on other sites More sharing options...
Voltageman Posted August 5, 2006 CID Share Posted August 5, 2006 Voltageman ;I wanted to know more about the underlined part.Should this filter be replaced if it is there or just removed? If you already have a filter in the grille..I mean one that is inside the return grille, then you can remove that filter inside the unit(usually there is a filter track with either a washable filter or a fiberglass one.. It will just inhibit airflow...I normally put 4-5" thick Hepa Media filters in the return. They get just about everything, including pollen, and other small airborne materials. Every coil in the systems I install the Hepa filters, stay shiny clean. Edit: Hepa filter assembly example http://www.allpartsgrills.com/item513242.ctlg Quote Link to comment Share on other sites More sharing options...
justinlay Posted August 6, 2006 CID Share Posted August 6, 2006 I am not sure if this has been addressed, but you might have your freon checked. If it is low, have them fix the leaks. Even though it is fairly new, there are bad installs. Your telling me when i bought the house I had to get them out a week later and fix it. It had a leak inside the house. Then about a month later a new leak outside in the coil. so they put a new coil in it and ran for another 2 months. Then again it went down. So I told them i need someone that know what the hell there doing and fix this thing. This time there was a restrition at a coupling (outside), and there was something else. *Knock on wood* its working fine Quote Link to comment Share on other sites More sharing options...
Voltageman Posted August 6, 2006 CID Share Posted August 6, 2006 I hope they evacuated the system properly after they fixed the leaks, and installed a filter dryer....Some people just purge the system with nitrogen, and then some refrigerant. This will remove most of the water/air, but not all...Any water or air in system will cause major problems and short compressor life. Look for oil on the piping....If you find oil on a fitting, it most likely is leaking at that spot..As posted before, soap and water will find most leaks. They should have installed a filter either on the Suction line, Liquid line, or both(I normally put a dryer on both to be safe)... If you have the system repaired again, make sure they use a vacuum pump(will make the water boil @ approx. 50deg F), to evacuate the system, and ask them to install a filter dryer. This will collect any contaminants(water/dirt/etc). Why people can't braze is beyond me...I can count on one hand the amount of leaks I have had in thousands of installs over 10 years.... Its not all that hard to test... Fill the system with nitrogen up to about 110+ psi and leave it for 24 hours...If the pressure is still at 110+, you most likely have no leaks. If you do, it will leak at the condenser most likely since the pressures can go up to 250-300 psi if unit is dirty or it is extremely hot. Quote Link to comment Share on other sites More sharing options...
cholla Posted August 6, 2006 CID Share Posted August 6, 2006 I'm going to second Voltageman on the importance of vacuuming the system.The filters are a good idea too.I have vacuumed a severely contaminated automobile system for several hours before just to make sure. My dad was an appliance repairman & his main specialty was refrigerator & refrigerator repair. I wish I could braze & solder as good as he could.He used silver solder for some repairs & brazing for others. Quote Link to comment Share on other sites More sharing options...
Voltageman Posted August 6, 2006 CID Share Posted August 6, 2006 For A/C you normally braze... Brazing is easy, just takes practice...Can't be afraid to heat up the piping...Its gotta get a lot hotter for brazing..But you have to be careful...You can burn right through the copper...Once that piping just starts turning cherry red, you are good to go. And with brazing you must move the torch around the pipe, it will not flow around like soft solder, and if it does, it is too hot, and you are pretty close to making a hole. The pressures are lower with refrigeration, so silver solder can be used..Stay Silv is the best stuff...Stays shiny forever.. Trick for brazing...When you braze, you should have nitrogen running through the pipe while brazing. Just a small amount to displace the oxygen, or you will get a black film on the inside of the piping which is bad for the a/c systems...Most people do not do this, but you really should. This is where filter dryers come in...They will catch that crap before it clogs up an expansion valve or an orifice.. Quote Link to comment Share on other sites More sharing options...
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