[Bikehike]

When it's hotter you can raise the temp to 78 and the ac will work better imo. 74 is way too cool and the electric company will tell you that's why blackouts occur. Set it higher and go to a rec center if possible for a few hours. Your electric bill will thank you also!

Also older ac units are not as efficient as new models. When we replaced our 15 yo unit the house cooled better and our bills were less because the new technology was so much better.

[Bikehike]

BTW my ac was on 79 yesterday and it feels cool because it's 90 outside.

[GRACEALLEMAN]

Originally Posted by Dr.Butler

Hi all. So central AC is essentially a foreign concept to me. My unit is 15 years old but seems to be working fine, and I am of the mindset that if it is not broken..... BUT I notice that for example yesterday, I set the unit to 74 degrees. During the heat, it went up to 77 degrees. The house felt fine, but it seemed like the unit was not keeping up? By the evening it went back to 74. I recently had the unit inspected and topped off with the coolant. So I guess the question, is this essentially normal/expected behavior?

You need to call the professional air conditioning company. If you think that this format is gonna answer your question about AC you are incorrect. You cannot survive this summer without it. Call immediately MUNNS AC

[msilagy]

Could be your thermostat isn't working well.

[MandoMan]

Originally Posted by Bill14564

You should probably have a reputable company look at the system to ensure it is working correctly.

Our AC/heat pump was putting out 60 degree air yesterday. We set the thermostat to 76 and it had no problem keeping our house cool. That is normal for us but our home is relatively new (<10 years) with good insulation.

Several factors can come into play. If the system isn't working correctly then the system itself might not be getting cool enough. If the filter or coils are dirty then it might not be moving enough air. If the system is undersized then it won't move enough air. If the home isn't sufficiently insulated then regardless of how well the system works it won't be able to keep up with the heat coming in.

A reputable company should be able to tell you if the system is working properly and if the filter and coils are clean. They should also be able to comment on whether the system seems to be sized correctly. We are happy with Munn's though I'm sure there are other companies to choose from.

You are right about the filter. It’s unlikely that the AC is undersized. It’s also unlikely that it needs to be “topped up.” More insulation might help. Hard to know without checking. Air Conditioners have on off cycles. When they reach the desired temp, they turn off until the thermometer in the thermostat reads that the temp has gone up two or three degrees. Then they turn on the AC again.

[Iowagirl2]

Originally Posted by rjm1cc

It could be that it is not large enough to get 74 in yesterday's heat. Since 77 was fine why not use 77?
Up North (runs in the summer) my A/C ran about 15 years. I think at 15 you are getting to the end of its life. Assuming your new A/C will run for 15 years why not get it now instead of in a year or two after it breaks down. My assumption is you will buy a new A/C one more time in your life. So why not now?

My air conditioning unit was getting old so I went ahead and changed it rather than wait until it gave out. One of the main reasons is I heard that air-conditioning units or heat pumps were going up 25% in the near future.

[toeser]

Originally Posted by snbrafford

My AC unit is 13 year old - original equipment. When I moved here 4 years ago, I "purchased" a warranty (pay yearly) from Broward Factory Service. They have free seminars quite often at various restaurants. It covers repairs to A/C units under 5 tons and if they can't repair - replacement. When I signed up - there did not seem to be an issue with age of the unit. I pay them $99 a year to come out and inspect the units. They have had to replace a condenser twice at NO COST to me. The warranty also replaced a leaking hot water tank at no cost. I mention this as why replace a working unit. Other big ticket items are covered too so I suggest you check them out.

Be sure the house does not have one of those "energy saving" gadgets on it that limits your unit at times of high demand (like when its very hot and everyone's AC is running). I had one previously in VA and the house would sometimes get a little warmer as you describe and I can only guess if there were true savings. I'd rather be comfortable.

I looked up their reviews on Yelp. Notwithstanding your positive results, I don't think I will be using them anytime soon.

[Speedie]

Originally Posted by Dr.Butler

Hi all. So central AC is essentially a foreign concept to me. My unit is 15 years old but seems to be working fine, and I am of the mindset that if it is not broken..... BUT I notice that for example yesterday, I set the unit to 74 degrees. During the heat, it went up to 77 degrees. The house felt fine, but it seemed like the unit was not keeping up? By the evening it went back to 74. I recently had the unit inspected and topped off with the coolant. So I guess the question, is this essentially normal/expected behavior?

Before spending money, check to be sure the house air filter is clean. If clogged with dust, then air does not circulate as easily.

[stevekennedy3]

Originally Posted by Dr.Butler

Hi all. So central AC is essentially a foreign concept to me. My unit is 15 years old but seems to be working fine, and I am of the mindset that if it is not broken..... BUT I notice that for example yesterday, I set the unit to 74 degrees. During the heat, it went up to 77 degrees. The house felt fine, but it seemed like the unit was not keeping up? By the evening it went back to 74. I recently had the unit inspected and topped off with the coolant. So I guess the question, is this essentially normal/expected behavior?

My Trane A/C unit was built in 2004 and is now leaking coolant (410A). I called Broward who were kind enough to come out promptly. They topped off the coolant and then quoted me over $10M to replace entire system. No thank you. I ordered on Amazon a product called Nu Calgon Easy Seal Direct Inject to seal the leak. Also bought a 3 Way A/C Diagnostic Manifold Gauge Set to get the sealant into my system. Lastly, am replacing air filter, cleaning the fins on outdoor unit and all the junk on the bottom to improve the efficiency. (How to do all this is on YouTube). I hope to get a few more years out of the unit before replacement. All this for less than $200 and a few hours of my labor is more appealing to me than spending over $10M.

[Bill14564]

Originally Posted by stevekennedy3

...
then quoted me over $10M to replace entire system.
...

For $10M ($10,000,000) you could get several new units with very nice houses attached!

[retiredguy123]

Originally Posted by stevekennedy3

My Trane A/C unit was built in 2004 and is now leaking coolant (410A). I called Broward who were kind enough to come out promptly. They topped off the coolant and then quoted me over $10M to replace entire system. No thank you. I ordered on Amazon a product called Nu Calgon Easy Seal Direct Inject to seal the leak. Also bought a 3 Way A/C Diagnostic Manifold Gauge Set to get the sealant into my system. Lastly, am replacing air filter, cleaning the fins on outdoor unit and all the junk on the bottom to improve the efficiency. (How to do all this is on YouTube). I hope to get a few more years out of the unit before replacement. All this for less than $200 and a few hours of my labor is more appealing to me than spending over $10M.

I would suggest that you cancel the Broward contract and get 3 quotes for a new system, which will be far less than the Broward price. I doubt that the leak seal stuff will work.

[OhioBuckeye]

Good question! I cleaned mine like they said I should do once a yr. It only took about 15 mins. to clean & it did seem to help, but if you’re asking me how do I know it helped, to be honest I can’t really tell other than I know it was dirty because when I hosed out the cleaner it looked pretty muddy looking. My son in Ohio hasn’t never cleaned his & the way it looks neither did the previous owners, but I’m going to clean his when we go there in July!

[retiredguy123]

Originally Posted by OhioBuckeye

Good question! I cleaned mine like they said I should do once a yr. It only took about 15 mins. to clean & it did seem to help, but if you’re asking me how do I know it helped, to be honest I can’t really tell other than I know it was dirty because when I hosed out the cleaner it looked pretty muddy looking. My son in Ohio hasn’t never cleaned his & the way it looks neither did the previous owners, but I’m going to clean his when we go there in July!

If you are referring to the outside condensing unit, the fins on the coil are the most important part. If they are dirty, you will lose a lot of heat transfer efficiency. Also, if they are bent, you can buy a "comb" to straighten them. But, cleaning out the dirt at the bottom of the unit will not help much at all.

[Remembergoldenrule]

Totally normal when heat is extremely hot. Heat pump won’t be able to keep totally up. 15 degree difference is normal. It will take out humidity so feel fine. Born and raised in South. Don’t expect ever more than 77/78 in upper 90s or higher. Go to pool or watch favorite old movie You’ll miss the heat this winter. 😉

[bobchap]

I recently had the unit inspected and topped off with the coolant. So I guess the question, is this essentially normal/expected behavior?[/QUOTE]

You say that you recently had the unit inspected and topped off the coolant. If they had to add Freon to the system it means you have a leak some where in the system. The Freon is a closed loop system and you should never need to add Freon unless there is a leak. If it did not take much Freon it would probably mean it is a slow leak.