Why would my air conditioner not cool my house despite the repair guy saying nothing is wrong?
Ok first is this a heatpump or a regular AC unit. Is the valve he replaced a reversing valve or a Thermal expansion valve (TXV). If the valve was inside it was a (TXV) if it was outside it would be a reversing valve and most likely a Heat Pump. If it was a TXV give it about 12 hours as there is a piston to open and closes to adjust the freon for the heatload. If its still not working then your unit cool be undercharged or over charged. Ask for many diffrent tempetures if a tech is out there. You should request these tempetures Outdoor ambient temp. Sub cooling temp Superheat temp Indoor dry bulb temp. indoor wet bulb temp. supply and return temp. (theses should have a a 12 to 20 degree split) Make sure he added the right freon (refrigerant) hopefully he didn't add the wrong kind its happen. You can do a quick check on your AC unit too to see if its working. Place your hand on the larger pipe going to the outdoor unit it should be very cold and sweating. Then place your hand on the smaller line it should be warm to the touch. The other thing I can think of is that the there is a heat gain or air lost from the duct work and not sure if if your ducts run through your attic most likely if he checked the attic they do. I hope this helps its really hard to trouble shoot systems sometimes online with out more info.
It's 62 degrees inside my house. Is that cold?
That's a bit chilly for me, but the outdoor alternative is winter in MN. To me, it's chilly indoors if I have to wear socks or slippers. I love to go barefoot any time of the year! (Within reason.)
It is 104 degrees outside.Should my A/C be able to acheive 78 degrees inside?
Here's a couple of things: Your house might have been just on the edge of say a 3 ton unit or a 4 ton unit, and the builder may have put in the 3 ton unit to save him a couple of bucks. It would work fine unless it got really hot, like say 104. Now, I design A/C for a living, and the calculations are based on the 99% weather data, meaning that 99% of the hours during cooling season are at or below that temperature. The 99% temperature is only 98 degrees. That means that when it is over 98 outside, your A/C will not be able to maintain your thermostat setting. And the more consecutive hours over 98, the hotter your house will get. During the evening/night the problem is that the roof/attic absorbs heat during the day, and it probably gets to be over 130 degrees up there. When the sun sets, all the heat stored up there starts to dissipate down into your upper story, keeping the house hot. Even still, sometime during the night, the unit should be able to cool the house.
How long should it take to cool down a house with central air?
here's the thing about AC. It's usually designed to meet a 99% condition, meaning that 1% of the hours during the summer, it's too hot out for your AC to keep up. Basically that means that if you wanted to keep your house cool when it is near 100 degrees outside, you would have needed to buy a bigger air conditioner for your house. And then that airconditioner would be bigger than you need, except factoring in the hottest days. So on the hottest, sunniest, most humid days, your AC might not be able to keep up (until it cools down in the evening). Generally that means whenever it's around or over 100 out, unless you live like in Vegas, where it might have to get to 110. The fact that your house was getting cooler, slowly, means that the cooling provided by the AC was BARELY enough to keep up with the heat outside. Any hotter and your A/C may not have been able to cool down the house at all (though some cooling is better than nothing, you wouldn't want it to be 100 degrees in your house). Pull all your shades closed. Turn off all lights you aren't using. Maybe put another layer of insulation in the attic. All these things will help keep the house cooler, by reducing the cooling load on the house, so your A/C unit will cool the house down quicker. Also, have the refrigerant level (used to be called freon) checked. Make sure the filters inside are replaced regularly. If you have ducts in your attic, insulate them. You want to be able to get all the cooling you should out of your system.
AC not cooling when its over 100 degrees?
Quite simply, your air conditioner is not designed to overcome heat loads above 95 degrees. For every five degrees above 95, the system loses 10 to 15% of its capacity. No, I'm not kidding. Please don't put the thermostat on 65 and expect it to cool faster. It won't. Thermostats are a simple two position control; its either on or off. The lower you put the thermostat, the longer it runs and the higher load is placed upon the system.... Plus, if you are setting the thing on a higher set point to save electricity while you are at work, then walk in the door at 5:30 and set the thermostat to 65 and then wonder why it won't cool,.... well thats just foolish. What could be wrong? There could be structure insulation problems, there could be too much of your apartment facing west, or if someone is walking in & out of the door(s) constantly.... well, you know. Do your system a favor; keep cooking to a minimum, especially in the oven. Don't boil alot of water or fry alot. keep direct sunlight out of the windows. If your landlady will let you get one of those big ol' exterior bamboo roll up shades and keep sun off any exterior walls. Shower in a little cooler water -with the door closed and the exhaust fan on. These tips should help