Hot outside, still too hot inside...
Do you need to make your AC colder? We all know that feeling of walking into a store or office that has its air conditioner singing on a hot day. The atmosphere of cool air is such a welcome and comforting change, so how can you achieve those levels at home?
If your air conditioner isn’t getting your space as cool as it used to, then don’t worry, it’s not time for an expensive new replacement system. There are things you can do to make your AC colder through the hotter months.
In this blog, we’ll take a look at why your machine isn’t getting as cold as it used to. Plus, we’ll also list some of the ways you get it back to peak performance and make your AC colder.
But before we get into those commonplace issues and fixes, there are some things you can do around the home to help out or get the most out of your machine.
How to make your AC colder

Alter the thermostat
Getting your room to the desired temperature is a big job for your AC. But you can minimize the amount of time you spend waiting for it to manage the temperature by setting it to come on 30 minutes before you get home.
Let it run
We don’t mean to just leave it to keep running day after day. But when you head to the local store or out on a short errand, it pays to leave your machine running. It can be expensive to run your central air, but it’s leaving it running is less costly from a monetary and environmental standpoint than stopping it and starting it back up again.
Use a fan
It may seem a little overkill to go breaking out the fan as well as having the AC on. But because your air conditioner extracts the hot air from your room and pumps it outside, rather than blowing cold air into the room, using a fan can help circulate the cold air. This means your machine doesn’t need to work as hard, and it will serve to make your AC colder.
Make use of ice
Another simple way that you can make your AC colder is by placing a bucket of ice or a frozen bottle of water in front of the fan or vent. This can just add that extra icy kick to the air.
So if you’ve tried all those quick fixes, and none of them seem to make your AC colder, and you’re still being greeted by awful tepid air from your machine, it may be time to step up the fault-finding.
Why isn’t my AC cooling as it used to?
There could be a range of reasons why your machine has started to lose performance. So, let’s take a look at the most common issues and go through the solutions to ensure your unit is equipped to beat the heat.
- Faulty thermostat
- Incorrect fan setting
- Clean your filters
- External obstructions
- Check your coils
- Seal your home
- Leaky ducts
- Refrigerant leak
- Make sure you have the right size machine
- Extreme weather
Faulty thermostat
If you have issues with your thermostat, then you could see all manner of issues pop up with your AC. From short cycling through to just not turning on. When your machine’s thermostat malfunctions, there are some things you can do to bring it back online.
First off, check the batteries in your thermostat and ensure they are not the cause of the problem. If the batteries are fine, then it’s worth heading to check the breakers. The main AC and thermostat breakers should be in the “up” position. Power outages can cause these to click off, so flip them back on and see if that gets your machine humming again.
Incorrect fan setting
Staying with the thermostat, for now, a lot of the time your central air issues can be solved by looking at your fan setting. You need to ensure the interface is showing the machine in “auto” mode rather than just “on”.
That auto setting means the machine will click on when the temperature in the room rises above a pre-set level. If your machine does kick into life when the temp goes up, then you can assume it’s a fan-setting issue.
Clean your filters
Now that we’ve checked over the thermostat, you can move on to more of the internal workings of your machine. One of the most common issues behind your AC not cooling your space is clogged-up filters.
A lot of dirt, dust, and other debris can find its way into your machine, so it’s only sensible to keep them as clean as possible. You should be looking to clean or replace your filters every couple of months. But only try to clean your filters if they’re labelled as “washable”.
External obstructions
While we’re on the subject of cleaning your machine, it’s also worth taking a look at your external unit (if you have one) and ensuring it’s in the best place and clear of any obstructions.
The external portion of your system is the condenser, which expels the warm air from your system out into the atmosphere.
A lot of AC, not cooling, issues can be caused by vegetation blocking your external vents and forcing the system to work harder than it should. It’s best to make a note, every few months, to head out and make sure the unit “can breathe”.
Check your coils
Another part of that outdoor unit is the condensation coils. There are two sets of coils in most systems, the external set as well as the evaporator coils which reside in the internal machine.
Generally speaking, you should probably clean your coils once a year, but if you live in a warmer state and use your system more often, then it makes sense to up that cleaning frequency.
Seal your home
If you want to make your AC colder, then you should take the time to ensure any windows and doors in your home are closed. In addition, you should try to seal any potential cracks around the frames of those moveable surfaces.
Products like caulk or weatherstripping tape can help plug those gaps and make your AC happy.
Leaky ducts
If you’ve tried all the above and it didn't make your AC colder, then it might be time to call a contractor to at least clean your air conditioner’s ducts.
Leaking ducts is a more common problem than you might think. However, if you do have a leak then it can mean cool air, which should be finding its way into your space, seeps out into other unused areas of your home like the walls or roof space.
Refrigerant leak
There could also be an issue with your machine leaking coolant. As you may have guessed, the coolant is a liquid in your system which conditions the air and makes it cooler. If this vital liquid is being lost, then there won’t be enough to cool your room.
While you may be able to refill or patch your coolant reservoir, it’s probably best to have a professional come and look at replacing the reservoir. Replacing the component is better for the overall running of your machine and the environment.
An easy way to tell whether you have a refrigerant leak (other than the room not getting cold) is to listen to your machine when it’s off. If you can hear any hissing coming from the unit then it’s a good sign that you’re leaking coolant.
Getting the size of your machine right
It may sound like an obvious problem, but if you don’t have the right size machine in your room, then probably won't make your AC colder. Plus, if your machine isn’t big enough to fill the space, you may find that it starts to short-cycle as it’s forced to work harder than it should.
Extreme weather
Another thing to bear in mind when it comes to your machine not getting cool is the external temperature. In extreme temperatures, you may not succeed in attempts to make your AC colder.
Ordinarily, if you want to make your AC colder, remember that air conditioners can only reduce the temperature in your room by around 20 degrees. So if your region has been experiencing super-hot conditions over a number of days, the room won’t get that cold regardless of how long you run the system.
When do you need a new machine?
Your air conditioner unit should last around 20 years and, as we said at the start of this blog, but if yor attempts to make your AC colder are not working out, that's not always a sign of needing a replacement system. However, it could be one of a number of ways you can tell that it’s time to move on.
If the inability to make your AC colder is accompanied by any of the below problems, then you may need to start looking for alternative systems:
- High-pitched noises when you turn it on
- Utility bills creeping up
- Running for longer without cooling the house
But, while getting a new machine can be a large initial expense, it could end up saving you money on your summer bills. When you just can't make your AC colder, it can be a problem that affects you and the environment.
To make your AC colder in the height of summer is a great thing. But in order to make your AC colder in your home throughout the hotter months, it pays to stay up to date with your machine’s general maintenance.
How long should it take to cool a house from 80 to 72?
On average, it can take around two and a half hours to cool a house from 80°F to 72°F.
Should I turn off AC if it's not cooling?
If your air conditioner is not getting your room cold you should shut it off. In the first instance you can check to see if the filters and coils are clear of dust and debris.