Austin Air Companie Blog : Posts Tagged ‘AC temp goes up in afternoon’

AC Cools But Doesn’t Cool Well All The Time

Saturday, July 23rd, 2022

Hi welcome to the #1 Katy Texas Air Conditioning Blog. This topic can be quite confusing at times because your air conditioner works by science not by magic.

The terms I use here are going to be terms that anyone should be able to understand. I remove as much technical jargon as I can to convey this subject so more people can understand it. (It’s not about writing it so I understand it.)

Air Conditioning Removes Heat

So the reason behind this post is that when record breaking temps come to town most air conditioners are going to struggle. It is completely normal for your thermostat temperature to go up in the afternoon under a heavy heat load.

With that said, this AC activity can point to trouble as well. Many people when they see this they think the thermostat is bad, their AC unit isn’t big enough, I might need some Freon and a laundry list of other potential guesses.

Air Conditioning doesn’t produce cool. It removes heat and the absence of heat is a cooling effect. That is what I mean by science. There are limits just as much as anything else. Trying running 50 miles with no breaks, to understand the point. Try driving your car with no gas or no electric if an EV. Everything has limits. But when it comes to air conditioners people repeatedly think they can put that thermostat dial anywhere and get it to get there.

Freon from above means refrigerant. This substance is more or less a solvent that was specifically designed for your air conditioner to remove heat from the structure. It is important that your system has the right type of refrigerant as well as the proper level. Too much or too little and your AC system will not remove heat properly and in triple digit heat (outdoor ambient temperature) will be costly to operate not to mention may not provide the cooling effect you are looking for.

Air Conditioners Don’t Use Up Freon

An Air Conditioner is a completely sealed system. The Freon in your AC will last indefinitely, unless the system has a refrigerant leak. Improper maintenance or service procedures can introduce leaks as well as age of the system can create refrigerant leaks over time. The older the equipment is, the more likely that the equipment is to blame.

However, just because your AC unit isn’t that old doesn’t necessarily mean it is free of refrigerant leaks. Air Conditioners are machines, and machines break – old and new alike.

In or near Katy, Texas? Call The Old AC Pro: Ray Austin 832-475-6895

Freon Leak Sealers / Additives To Stop Freon Leaks

I’ve used a couple of these over the past few years, but I have found they simply do not work. My definition of working is that they fix the refrigerant leaks. If they don’t do that, what is the point?

My opinion is that adding a Freon leak sealer to a system is attempting to take a short cut rather than to fix something the right way because the right way costs more money.

But if the refrigerant leak is not fixed, it will cost you more money anyway because the costly refrigerant will continue to leak out. The other less thought of problem with leak sealers is that you are placing something into your AC refrigerant system that does not belong there. This could lead to other problems later.

Watch the embedded video below how to properly fix Freon Leaks and stay tuned to just how well a leak sealer worked in a test I performed.

Live in or Near Katy, Texas? Your own personal AC repair Easy Button:

Call Ray Austin 832-475-6895

Substances Not Condensing In An AC System

A refrigeration system is critical to be a clean environment free from things that contaminate the system. The AC system is a sealed system remember? So if contamination is introduced the system isn’t going to work properly.

This problem is more so magnified in a record breaking heat wave. Your AC system’s operation is dependant on having the proper refrigerant, the proper amount with every thing fluidly moving about. If too much refrigerant is placed in your AC system it won’t work just as much as if it has too little of refrigerant or the wrong type. Freon is merely a brand name. I know what type your AC system needs, but I don’t know the service history if you call me for the first time. If a refrigerant circuit in your AC is blocked up it’s not going to work properly in triple digit heat.

Air is a common ingredient that will not condense in a refrigeration system. This only gets inside your refrigeration system by someone not doing something they should have done. Putting a leak sealer in the system could do essentially the same thing. The common reason people do this is that the system is older and will at times say I have nothing to lose.

Then replace the system a few years later, reuse the line set that possibly has some of this contamination left behind. It can be quite difficult to replace line sets on some homes and that difficulty can add a good sum of money to do so.

Did you know that the refrigerant in your AC system goes thru phase changes in side your AC’s refrigeration circuits? This is necessary because the pump otherwise known as the compressor is a vapor pump. Trying to compress anything other than refrigerant vapor will damage the compressor. If that happens? YIKES, not good.

But your AC’s refrigerant system also contains refrigerant in liquid form. Without that it simply will not work. It’s not magic, remember?

Your Air Conditioner Is Doing All It Can

This could be true, just as much as it could be false. Just because you dial in 70F on your thermostat doesn’t mean your house will get that cool in triple digit heat (100F and up – we’ve been hitting 102 and hotter recently in the Katy, Texas area.)

Design temperature plays a role. In our climate in Katy, Texas design for this area is 75F inside with 95F outside. These are design parameters. Does this mean you will never get lower than 75F inside? No. The heat of the day or the hottest part of the day is typically 3pm-7pm or 3pm-8pm during unusually hot record breaking periods.

These events as well as the condition of your AC system, your home’s thermal envelope conditions, duct work, system design and how you operate the system can all have an effect (good or bad) as to how hot or cool your house is.

A Not So Cool Story

Part of the reason for this blog post. I recently ran an AC service call in which the home in question was a rental house. The tenant recently moved in and not accustomed to the Katy, Texas climate just yet… or so this is what was relayed to me. I only know what you tell me, the rest is nothing more than a series of guesses.

I have never been to this house before. So I have no service history to go off of. I am walking blind so to speak. The system had recently been repaired, part of the AC system was replaced by another HVAC company. (Single story home, one HVAC system)

I get there (to the rental house) and the thermostat is reading 72F with nearly 100F outside. So on face value you could say this air conditioner is doing all it can. Essentially that would be true. But that unfortunately doesn’t go far enough.

Because taking AC service readings into consideration points to a bigger problem that only gets bigger the further I dig. It didn’t take long because this job wasn’t mine I was only there to “check out the work” that was done by another company.

Why was that necessary?

Because the other company had been out there a couple of times already saying the AC system is doing all it can do. The home owner decided to do the right thing and investigate further at additional cost. Not doing so could eventually turn into a revolving door of tenants moving in and out. That is costly in the home rental business. I know because I also own a rental house. Experience is worth what these days?

The ramifications of what I found? Split temperature / Differential Temperature / Temperature Drop / Delta T. What ever you wish to call it… was 12F. This should be 15-20F degrees. Preferably the closer to 20 the better for our climate here in Katy, Texas. Because as our design parameters describe you should have closer to a 20 degree temperature drop across the coil. Although any thing above 15F would be considered a passing grade.

So just that test alone I expected the AC system to be low on refrigerant. But that is not what I found. Because I don’t have any past service history I am led to guess what may or may not have happened here. (Contaminated System / Improper methods / Some other issue not yet known)

This is also to suggest you can’t just go with what you think the problem might be. As adding refrigerant to this system would only make things worse. Removing refrigerant won’t help either. The difference from proper to improper. Living with it? I suppose you could live on the edge but additional failures on your dime? Remember Katy, Texas is a hot climate. We separate the men from the boys in this climate on a fairly consistent basis when hitting triple digit temps. Not to brag, but I know what works, I also know what won’t work. So because I am not the installing HVAC contractor I can only guess what they did do as well as what they didn’t do but should have.

Guessing is not only dangerous but also costly. This customer ( home owner of this rental) has used me for work before. This wasn’t a free call – my opinions are worth paying for I am not nor have I ever been a gimmick provider. Service history is what determines what costs may be for me having to go behind someone else.

There is no warranty for improperly installed equipment. Currently the home owner had decided to get this company to go back and fix this system. The excuse this other company has been using isn’t going to fly now. The tenant is by now relieved that they’re no longer considered ‘nuts’ or making stuff up.

The AC Is Doing All It Can

When you’ve been doing HVAC Repair & Service for as long as I have you get the opportunity to see it all. I don’t just work on rentals, but this story is yet another rental. These stories provide unique insight to this AC blog post topic.

I think the reason for these kinds of stories is that tenants will push HVAC systems quite hard. This particular system has two floors with one system and thermostat on the top floor.

So this story goes to places the other call could only dream of. I have service history of this address so I know the complaint is likely bogus before I even get there. But I still have to “check it” because if you don’t you’re guessing and guessing doesn’t work in HVAC. I have a reputation of telling it like it is. Not going to stop now even if I think you can’t handle it. At some point you’ll have to put on big boy or big girl pants just like I do every morning.

I get there I have a conversation with the tenant and they claim to have to blast the AC at night so the room on the lower level doesn’t get too hot. Also that in the after noon the temps rise on the thermostat on the second floor. Which is normal by the way in triple digit heat.

Upon checking the unit while I was discussing things with the tenant on first floor the AC cycled off. I began this check with room temp on top floor at 69F at the thermostat.

In order to check this AC system I dropped the temperature to 65F to force it to run so I could perform the check. The Delta T / Temp Drop across the coil was 22F. This particular AC was installed by me. I have been servicing this property for a number of years.

Notice the difference in Temp drop from the first one? 10F better.

Operating Pressures? Outstanding. (These fluctuate so it’s pointless posting this information.)

Because of the nature of a tenant occupant I even recorded the temperature in the master bedroom suite on the lower floor. 65F — yet design is 75F. So you can see how these things can vary from one home to the next. No two homes are alike.

Everyone’s view of what comfort is can and will be different from other viewpoints. But design is the limit. This particular property has a control on the top floor with one HVAC system so it will always be warmer on the top floor. (Heat rises)

And the thermostat on the top floor does not now how hot or cool it is on the lower level. These design flaws can be fixed. But that costs money.

The HVAC Comfort Business

HVAC is a big box of comfort. Service is part of that, just as much as design and all these other factors. The HVAC product & design you choose has limitations. It doesn’t work by magic and your definition of work should mean more than “The unit turns on, The unit turns off”

Because there is more to it than just turning on or off. It must be doing so properly and efficiently. What is properly to someone who doesn’t know?

I thank you for visiting with me today. I hope this subject may help you garner more understanding in relation to how you view comfort the choices you make for those that provide it for you.

As always I hope your day is comfortable.

About the Author of this Katy, Texas Air Conditioning Blog:

My name is Ray Austin owner/operator of Austin Air Companie a small HVAC service company that services the Katy, Texas area and some surrounding areas. I write my own blogs, I make my own videos, No investors, no intimidation to tell you like it is. My HVAC career is 28 years long, 14 of which running and operating my own HVAC service company.

If you call me, you will get me. There is no technician roulette wheel to spin here at Austin Air Companie.

If you are calling me I will inform you of all choices after inspecting your HVAC system(s) in person and even repairing your air conditioner if that option makes sense. I am skilled in working for you, not just recommending something that is only beneficial to me. It’s about providing you an air conditioning service that you can rely on. I will do my best to explain the risks of doing what you decide to do. That is what a skilled HVAC contractor can do for you.

Let me know what your concerns are. Comfort means different things to different people. We are all unique that way. A solution I like, might not be right for you and vice versa. System Design is a wide varying topic but is very important as to the comfort level that system will perform.

Serving Katy, Texas and some surrounding areas. Call Ray at Austin Air Companie Today! 832-475-6895.

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