If you have a garage in Central Texas, you know the drill. By mid afternoon in July, that space is a furnace. You might be thinking about a mini split to turn it into a workshop, a gym, or just a place you can stand without sweating. But how cold can it really get when the walls and ceiling have no insulation? Let's look at the facts.
If you have a garage in Central Texas, you know the drill. By mid afternoon in July, that space is a furnace. You might be thinking about a mini split to turn it into a workshop, a gym, or just a place you can stand without sweating. But how cold can it really get when the walls and ceiling have no insulation? Let's look at the facts.
A ductless mini split is a powerful tool for cooling. But it is not magic. In an uninsulated garage, the system has to fight against the sun beating on the roof and the heat radiating from the concrete slab. The honest answer is that a mini split can make a dramatic difference, but you will not reach the same 70 degrees you might get in a well insulated living room. That is okay. The goal is to turn a dangerous oven into a tolerable space where you can work and store things safely.
An uninsulated garage in Texas is basically a solar collector. The roof soaks up heat all day, the concrete floor holds it, and the metal or thin wood walls do little to stop it. On a 100 degree day, the inside of an uninsulated garage can easily hit 120 degrees or more. A mini split is designed to remove heat from the air, but it can only do so much if more heat keeps pouring in through the walls and roof.
That does not mean the mini split is useless. It will lower the temperature significantly. But you should expect a realistic outcome. In a typical two car uninsulated garage, a properly sized mini split can often bring the temperature down by 20 degrees or more. That means from 120 down to 100 or even 95. That is still hot, but it is survivable. And if you add a little insulation later, the performance will improve. The mini split gives you a foundation you can build on.
A mini split in an uninsulated garage will run longer and harder than it would in a finished room. It might run almost continuously during the hottest part of the day. That is normal. The system is designed for that. It cycles on and off less often than a window unit, so it can maintain a steady temperature even when the outside is brutal.
How low can it go? That depends on the size of the garage, the outdoor temperature, and the amount of shade. On a 95 degree day, you might see the garage drop to 80 or 85. On a 105 degree day, it might only get down to 95. The key is that the mini split will keep the temperature from climbing into the dangerous range. It will also remove humidity, which makes the air feel cooler and helps tools and stored items stay in better shape. For a workshop or a home gym, that is a huge improvement.
You have other options for cooling a garage. A window unit is cheaper upfront, but it usually sits in a window or a hole in the wall, which can be a security risk and lets in outside air. Window units also struggle to cool a large uninsulated space because they are not designed for that kind of load. A portable air conditioner with a hose is even less efficient. It vents hot air out a window, but it creates negative pressure that pulls hot air in from every crack, so it often makes the room hotter overall.
Central air could be extended to a garage, but that is a major project. Most homes do not have ducts running to the garage, and adding them is expensive. Plus, zoning can be tricky. A mini split is a dedicated system. It is installed right in the space, with no duct losses. It is quieter than a window unit and more efficient than a portable. For the garage, a mini split is often the best trade off between performance and cost, especially if you plan to use the space regularly.
In a typical Central Texas summer, a properly sized mini split can lower the temperature in an uninsulated garage by 20 to 30 degrees compared to the outside. But the final temperature depends on the outdoor heat, the size of the garage, and how much sun hits the roof. On a 100 degree day, you might see the garage stay around 80 to 85 degrees. That is a huge improvement over 120 degrees.
Yes, if you use the garage for anything more than parking. Even without insulation, a mini split makes the space usable for a workshop, home gym, or storage of temperature sensitive items. The system will run longer, but it is still more efficient than window units. And if you later add insulation, the mini split will work even better. Think of it as a step by step improvement.
Most two car garages in Central Texas are around 400 to 500 square feet. For an uninsulated space, we usually recommend a 12,000 to 18,000 BTU unit. Oversizing can cause short cycling and poor humidity control. The best way to know is to have a professional measure the space and consider factors like ceiling height, windows, and sun exposure. We do that as part of the installation process.
You can buy a DIY mini split kit, but installation is tricky. The refrigerant lines must be properly sized, vacuumed, and charged. Mistakes can lead to poor performance or compressor failure. Also, electrical work is usually required. In many areas, a permit is needed. Permit requirements vary by city, but we handle that for you. A professional installation ensures the system runs correctly and lasts longer. Our flat rate covers everything, so you know the cost upfront.
A standard installation for a single zone mini split in a garage usually takes one day. Our crew arrives in the morning, mounts the indoor unit, runs the lines, installs the outdoor condenser, and connects the electrical. By the end of the day, the system is running and you can see it working. The balance is due after you have seen it cool the space.
Ready to tame your garage heat? Call Jester Climate at (512) 297-7493 to book your flat rate $2,400 installation. A $400 deposit locks your install day and the rest is due when you see the system running.