Central A/C Help

emtjmac

My wife and I purchased our first home a year ago and it has central air conditioning. It is a Trane, the unit is only a few years old and I do not know it's service history. I feel like it could really do a much better job cooling our house and keeping it cool. There are some days when it is 90+ degrees and humid outside and we can only keep the house, at best, around 76-78 F. We have tried setting the thermostat at anywhere from 50 to 74 with no change in performance. Some of the vents seem to leak the cold air into the room rather timidly while a couple of vents blow a little more vigorously. We don't have the money to call out an HVAC technician and have no plans to do so. Any advice from experienced homeowners or people with related experience would be much appreciated.

ldrosophila

All your vents are open correct? You could have some leakage among the duct work is it possible for you to take a look and then seal it up with some ducting tape? IDK I'm not an HVAC expert thats just what the tech told me when they came out.

PS-76 seems cool enough to me, but you must not pay high electric bills where you live.

emtjmac

Electricity bills are high everywhere. I'll check the duct work in the basement for leaks, that's a good idea. Thanks!

blt0087

At least you have central air! Our house was built in the 50s and doesn't have it..Texas summers are awful, but its like having my own personal sauna

Have you tried closing vents in the rooms you're not in? We did that in out old apt, and it seemed to help keep the occupied rooms cooler.

CheekyBrahette

Make sure to replace the air filter! A dirty filter can cause decreased airflow. Also, is the unit big enough to cool the square footage of the house? Keep in mind that an AC unit can only make about a 21 degree difference. So setting your thermostat at 50 won't do you any good on a 90 degree day. Hope this helps. ^_^

How do I know this? I worked for an adult school for HVAC and commercial refrigeration. My ex-husband was also a Master Commercial/Domestic Refrigeration & Air Conditioning Technitian.

zagon_the_ultimate

inside each pipe, or duct there should be a large butterfly flap valve. for each vent out into a room, there will be one flap valve. this is so you can adjust the airflow to room specificly due to air resistance, and pressure loss along the system (also for personal "i like my bedroom cold" types). you can play with these to get a general flow of your choosing.

your problems seem to be more general flow based, or thermal output based. schedule a service for the unit, especially since you dont know its history. it could be low, or in dis-repair, this requires checking the pressure of the unit itself. over time, every system leaks a bit, even the brand new ones. a good check of this is to feel the air coming out of the condenser unit to see if its warm. if it isnt, then its not transfering heat properly, feel the coil fins to get a better idea. also checking both feed pipes going to the unit, one should be wrapped in insulation and be extreamly cold. if it is not cold you probably have either a low charge on the system, or the compressor is in disrepair.

a more annoying problem is that the inside of the evaporator coil (in the furnace stack itself) has become caked with dust and hair, and has formed a mat. the filter generally prevents this, but over time enough can slip by to build up. cleaning this is a major pain, and generally requires partial dissassembly of the primary ductwork, moving the evaporator, and cleaning off the mat. the GOOD news is, if its caked from years of neglect its generally easier to remove, cause it acts like felt.

cherio256

We had the same problem. Cool air coming out but hot in house. Had it checked out a few times and they claimed there was nothing wrong with it. Decided to use window units and its cooler and bill is cheaper.