Installing a DIY Air Conditioner Yourself

By installing a DIY air conditioner in your home on your own, you can save money, time and energy. While the average cost to replace heating and air conditioning is what prevents people from hiring an HVAC technician, you can DIY the project for a fraction of the price. Considering the equipment, labor, installation of ductwork and the complexity of your home AC system, you'll save so much money on your HVAC replacement cost.

You would know if you need to replace your HVAC system if you see these warning signs in your air conditioner:

  • It's not blowing out cold air.
  • It won't start.
  • The coil has broken.
  • It's on fire.

When looking for a DIY air conditioning kit, don't settle for junk. Get a high-quality air conditioner that is easy to install, with a warranty included in the new AC unit cost. Use this guide to set up a system to control the temperature in your home.

Is Installing a DIY Air Conditioner Safe?

Installing a DIY air conditioner is relatively easy, but safety should always be your priority. You should only put up an air conditioning unit yourself if you feel comfortable doing so. If you get stuck at any time during the unit install process, we offer lifetime technical support on all our products.

Follow these safety instructions to avoid getting hurt or damaging your property:

  • Regularly maintain your HVAC unit: HVAC maintenance can lower your HVAC system cost since mold and debris from an old machine can make the installation more difficult. Clean your air filters at least once a month and replace them as needed. To prevent corrosion in your coils, clean them often or hire a technician to do so. Inspect the drain lines and pans to make sure the water is flowing smoothly. You should also check the refrigerant charge and remove debris around the outside unit.
  • Read the instructions: No matter which system you end up using, set up all products or accessories for your cooling system according to what it says in the instruction manual. Your new HVAC system should comply with local and national regulations for mechanical, building and electrical projects. If necessary, get local permits for your HVAC installation.
  • Use protective gear: If you make a mistake during the set-up process, it can hurt you and your living space. Wear safety gloves and even goggles if you feel they're necessary. Be cautious if you have to handle sharp sheet metal.
  • Call for backup: While an HVAC installation kit makes the project much more manageable, you should ask for help if you feel unsafe. Only handle refrigerant and high-voltage electrical wiring if you have the proper training. Call a friend or family member to help manage the equipment or provide easy transport from each part of the house.

What Unit Do You Have?

If you don't know what unit you currently have, you can find out by looking at them. Check out these characteristics of four different home air conditioners to identify which one you have in your house:

  • Portable air conditioner: These mobile, flexible systems are freestanding, which allows you to move them quickly throughout the house as needed. You can install these AC units on the floor through your window, a drop ceiling or a prepared hole in the wall. Use portable air conditioners for a temporary area or where it doesn't make sense to have a window-mounted unit.
  • Window air conditioner: These energy-efficient, versatile units can serve as either a primary cooling source or along with a central AC. Install your window air conditioner through a window or a prepared and measured hole in the wall. The unit comes with all the refrigeration components in a simple, compact box. Window air conditioners are efficient for single-story homes or smaller two-story homes.
  • Central air conditioner: As the most common type of conventional air conditioner, central split duct systems blow the same temperature throughout the entire home. The split systems provide cooling and dehumidification as well as heating in the winter.
  • Ductless mini-split system air conditioner: These high-efficiency air conditioners feature a quiet performance that can cool various parts of the home at once. You may have seen them in hotels and multi-unit buildings since they can adequately control the indoor air temperature of each room. Ductless mini-split system air conditioners require a sizeable outdoor condenser unit and a small blower unit that mounts on the wall inside the house.

What Do I Need to Get Started?

If you do the whole project yourself, you'll need a variety of tools, like an L-square, a wrench, wire cutters and other fancy items. With the Ductless Mini Split from MRCOOL, you only need these tools and supplies:

  • The air conditioner, of course.
  • Pliers with an adjustable wrench.
  • Cross-tip screwdriver.
  • Water and soap in a spray bottle.
  • A drill and drill bits according to the instructions for the DIY kit.
  • A handheld stud finder.
  • A 3.5-inch bi-metal hole saw with an arbor.

You can get most of these tools at a local home improvement or hardware store. The MRCOOL DIY is a pre-charged and sealed system, so it doesn't need a vacuum pump. Everything you need for this project is right in the kit, so you'll save money on the AC unit cost.

Do I Have to Do Anything to Get My House Ready for Installing a DIY Air Conditioner?

With a DIY kit, you will have to do minimal work to get the room ready for installing your air conditioning system. You can have the AC cranking through the house in a matter of hours. As you prepare the home, and yourself, to replace your AC unit, here are some steps to consider:

  • Select the right AC unit: Picking out the type of air conditioner unit you need isn't quite as simple as going to the store and grabbing the first one you see on the shelf. You also need to measure the area that you want to cool to find out what size unit you need. A ductless mini-split system is easy to install because it doesn't require the addition of ductwork throughout the house.
  • Find a spot for your new AC unit: The location for both the indoor and outdoor units of your air conditioning should be on a level and firm surface. If possible, keep the outdoor unit out of the sun or away from a gutter so it will run more efficiently. As you look for a wall that connects to an empty spot outside the house, remember that the MRCOOL DIY kit includes the copper refrigerant line that measures about 25 feet.
  • Clear away bushes and other obstructions: The outdoor unit should be in a space away from branches and plants for the proper airflow. If you care about the curb appeal of your house, you also should put the outdoor unit in a space that's out of sight, far from an electric or gas meter. Cut bushes away or move around furniture to make room for the exterior unit. Once you've found and cleared a space outside, lay down a condensing pad on a level surface and center the condenser on top.
  • Cut a hole in the wall: Use the wall template included in the DIY kit, a mounting plate and a level to mark the place where your indoor air conditioner unit will go. The stud finder will locate points to help you create a level line for the mounting plate. Double, triple and quadruple check that the wall template is plumb and level each time you complete a process in the unit install. Now comes the fun part. Using the bi-metal saw, drill a 3.5-inch hole on the right of the mounting plate to run the wiring. Cut the hole at a slightly downward slope to accommodate the drain piping.

What Is the Line Set and How Do I Install It?

A line set connects the indoor and outdoor AC units of a ductless mini-split system or a central air system. This system consists of a suction line, which connects the evaporator outlet to the compressor inlet, and the liquid line, which connects the condenser to the expansion valve. You would need to replace the line set when you install a new AC unit.

Here are the steps for installing a DIY air conditioner line set:

  • Insert the sleeve: The sleeve of wiring should be in a package together in the MRCOOL DIY kit. You might want to have a friend or family member stand on the other side of the wall to catch the piping outside.
  • Keep the piping and wires: Since the copper piping could kink when you bend it, make sure it stays straight as you move it through the hole. You could do this by holding the end down with your foot or taping it. At this point, you can install the unit on the indoor wall by snapping it into the mounting plate.
  • Bring it all together: On the outside of the house, connect the piping to the outdoor unit. Refer to the wire guide on the panel in the condenser, or call an electrician to connect the refrigerant lines. Thread the wiring by hand and use an adjustable wrench to tighten it. Be careful not to cross the pipes so that you don't kink the wires. Use soapy water to check for leaks after it's all connected.

How Can I Prepare My High-Voltage Connections?

An air conditioner runs on a significantly high voltage of electricity to establish a connection with the main electrical circuit panel. While you can prepare the wiring for a hook-up, only a skilled contractor can take on dealing with high-voltage wires. If you try to take on the project by yourself, you could shock yourself and damage your property. Plus, your AC probably won't work.

To prepare the high-voltage connections for your AC unit, choose the right wire thickness and corresponding breaker for your condenser. High gauge numbers indicate a thinner wire. Check the instruction manual for your air conditioning system to find out the gauge of your unit's connections. After you know which wires are correct for your installation, here are some steps for preparing the high-voltage electrical system:

  • Set up the disconnect box and electrical whips.
  • Mount the whips to the ceiling and connect the flexible wire through to the electrical panel of the home.
  • Install high-voltage wiring to the condensing unit.

How Do I Connect the Low-Voltage Wiring?

Low-voltage connections run from the thermostat and the inside furnace to control your air conditioner unit. These connections are safer than working with light fixtures or power outlets because there is less of a possibility for electrocution. While these will not be necessary for installing a DIY air conditioner, here are some tips for installing your low-voltage connections:

  • If you took a break from installation after your high-voltage connections, make sure the electricity is off.
  • Push the low-voltage wire set into the control box through the access opening.
  • Use a razor knife to remove a few inches of the outer plastic sheathing from the cable.
  • Strip a little less than an inch of insulation from each inner conductor using wire strippers.
  • Twist together the low-voltage wires and secure them with a wire nut.
  • Connect the low-voltage wires to the condensing unit.
  • Carry low-voltage wiring along with the ceiling to the furnace or the air handler.
  • Run wires from the furnace or air handler and connect to the thermostat.

After installation, you should always check that your AC unit is running smoothly after turning on the electricity. If you notice any weird noises or smells coming from the air conditioning system, call the manufacturer or technical support.

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