What Is The Minimum Distance Between AC Outdoor Unit And Wall?

Proper installation is critical for air conditioner function. If the unit is installed incorrectly or without observing local codes, there’s a risk of inefficient performance and possible damage to the unit.

As a result, installers must ensure optimal clearance distance around the AC outdoor air conditioning unit. Otherwise, the unit may not pull enough air to cool the condenser.

This can result in condenser overheating in the outdoor unit, potentially resulting in parts damages. In addition, poor airflow in the outdoor unit is also bad for air conditioning efficiency.

Read on to learn the recommended minimum clearance distances around your air conditioner’s outdoor unit, including the minimum distance between the outdoor unit and the wall, how to deal with obstructions, and the benefits of site inspection.

What’s the Minimum Distance Between the AC Outdoor Unit and the Wall?

The minimum clearance between the air conditioner’s outdoor unit and the wall is 30 inches. You must maintain this distance at all times to ensure enough cool airflow for efficient air conditioning. Otherwise, you may not get enough cooling and may even lose your product warranty.

Why You Should Follow Proper Clearance Requirements

You must install all air conditioning systems following industry regulations, which require sufficient clearance all around the appliance. Leaving enough clearance around the outdoor unit is important for three main reasons;

Ensure Maximum Cooling Efficiency

You want your air conditioner to cool with maximum efficiency, i.e., use the least amount of power to keep your rooms cool throughout the summer. Unfortunately, not providing enough clearance impacts airflow, reducing the cooling efficiency.

For instance, you need airflow into the condenser to remove heat from the refrigerant. The heat extraction process is negatively impacted if airflow into the condenser is compromised.

And, when heat extraction is compromised, your air conditioner must work harder to maintain the thermostat setting. Poor airflow can also cause ineffective cooling.

Avoid High Cooling Bills 

Whenever your air conditioner is forced to work harder to keep you comfortable, your energy bill goes up. Why? Because “working harder” is just another word for drawing more electricity.

For instance, think about the fan working harder to draw air into the condenser. It only means that the fan is running faster and longer – both of which require more power.

The more limited the clearance space, the harder the fan and other AC parts must work to keep you cool and comfortable.

Avoid Potential AC Damage

One of the dangers of poor airflow in the outdoor condenser is overheating. As we’ve mentioned, the condenser depends on reliable airflow through the outdoor unit to expel heat extracted inside your house.

Now, imagine when there’s not enough airflow to remove the heat! There would be overheating within the outdoor unit within no time. Overheating in the outdoor condenser can damage the condenser, compressor, or the entire outdoor unit, necessitating complete AC replacement.

General Clearance Requirements 

Clearance requirements may vary depending on your geographic location, type of air conditioner, and other factors. Therefore, you should always follow what your manufacturer says first. Everything else comes second.

Nevertheless, the following are the general clearance requirements for a standard air conditioning system;

General Working Space Around the air Conditioner

When installing your air conditioner, you need to leave sufficient appliance access clearance distance. Otherwise, it becomes very difficult to install wiring and refrigerant piping.

The recommended minimum working distance to the controls is 36 inches, or 30 inches for UMC units, on the side controls and fittings are located.  

Clearance to the Service Side of the Outdoor Unit

All air conditioner condensers also require servicing, both regular and scheduled. Therefore, you must leave at least 24 inches of clearance on the service side for easy accessibility.

However, some units, such as the Lennox Elite IOM, require at least 30 inches on the service side for accessibility. So, again, check with the manufacturer.

Clearance Above the Outdoor Unit 

To provide proper air circulation, you must leave at least 48 inches of clearance above the compressor/condenser unit. However, this requirement may be higher, especially in locations with overhead obstructions.

For instance, you need at least 60 inches of clearance distance in locations with overhead decks, soffits, or eaves.  

Clearance Space at the Sides of an Air Conditioner 

You need at least 6.0 inches of clearance on one side of the air conditioner and at least 12.0 inches on each of the other three sides for maximum airflow. However, the exact figures also vary depending on the manufacturer.

For instance, you need at least 36 inches on one of the other three sides, excluding the side closest to the control box. So, check with the manufacturer.

Clearance Space to Nearby Structures, e.g., Wall or Fence

Provide at least 12 inches of clearance between the outdoor unit and nearby structures, such as walls, fences, and other solid obstructions. However, some manufacturers permit reduced clearance to a single object with a small surface area, such as a post or outside corner. For instance, you may only need a 4-inch clearance to a post.

Clearance from an Inside Corner

If you’re installing the outdoor unit at a corner inside the building on a single-story structure, you need to evaluate the surrounding structures to ensure appropriate clearance.

For instance, larger overhanging soffits can cause air recirculation, impacting air conditioning efficiency. Again, speak to the manufacturer or HVAC technician about your options.

Other Clearance Requirements 

You must leave enough clearance between the outdoor unit and rooftops, doors, and windows. However, no code or manufacturer-specific guidelines are available for door and window clearances.

So, you need to read your manual to find out. However, you need at least six inches between the outdoor unit and the rooftop.

Dealing with Clearance Obstructions 

Obstructions, such as landscaping and construction machinery, also challenge locating the air conditioner’s outdoor unit.

The following are the recommended clearance requirements to deal with the most common obstructions.

Clearance in Case of a Construction Obstruction 

Construction obstructions include heavy machinery that may remain in place for the foreseeable future. If you’re installing the air conditioner’s outdoor unit near such constructions, you should maintain a clearance of at least two feet between the outdoor unit and the construction obstruction.

If you’re building an addition, make sure exhaust air vented by the outdoor unit doesn’t enter the new construction.  

Clearance in Case of Landscaping Obstruction 

Some homeowners prefer to install the outdoor air conditioner close to the landscaping obstructions, such as shrubs, long blade grass, and potted plants. This helps conceal the outdoor unit to maintain an attractive exterior look.

While this isn’t completely prohibited, you should ensure sufficient clearance to ensure maximum airflow. The recommended clearance is 2-4 feet.

Clearance in Case of Mechanical Obstruction 

Mechanical equipment, including kitchen exhaust vents, dryers, and heating appliances, can also obstruct airflow into the air conditioner. Furthermore, mechanical equipment producing hazardous gases, such as propane tanks, poses a fire hazard.

Thus, you need to maintain a clearance of at least eight feet between air conditioner compressors and the equipment. Alternatively, consider installing the air conditioner at a different location.

Clearance Requirements Between Two Outdoor units

If you have two air conditioners, such as a central air system and a complimentary mini-split system, you must leave 24 inches between their outdoor units for unimpeded airflow. This also reduces competition for outdoor air.

The same applies to an air conditioner adjacent to a heat pump system. However, some air conditioner manufacturers demand at least four inches (48 inches) between adjacent outdoor units.

What’s the Minimum Distance Between AC Outdoor Unit and the Wall? 

You need at least 12 inches between the outdoor unit of your air conditioner and nearby walls. However, this figure varies depending on several factors, including the appliance manufacturer. For instance, some brands require at least 20 inches to a wall, while others demand at least 30 inches. Ask your manufacturer if you’re not sure.

What’s the Maximum Clearance Between an AC Outdoor Unit and the Wall?

There’s none! You can place the outdoor unit as far from the wall as you wish as long as you have enough refrigerant piping and electrical wiring to cover the extra distance.

The only downside of installing the outdoor unit too far from the wall is that it creates new efficiency headaches. Additionally, wiring disconnections and refrigerant line leaks are more likely if the distance between the outdoor unit and the wall is too big.

Benefits of Site Inspection 

An easy way to avoid too little or too much clearance around your air conditioner’s outdoor unit is to get a professional inspection before the installation.

Hire a recognized HVAC inspection services provider and let the company help you determine the most appropriate installation location and advise accordingly on ideal clearance distances around the unit.

An inspection takes 45 minutes to an hour, and the inspector will issue a written review or report on the overall health of the air conditioner, including whether you have enough clearance.

Minimum Distance Between AC Outdoor Unit And Wall FAQs 

How Much Space do you Need for the Outside AC Unit? 

Depending on the installation conditions and other factors, you need at least 60 inches of vertical clearance and 12-30 inches on the other three sides of the outdoor unit.

Where should an AC Outdoor Unit be Located? 

Ideally, you should install the air conditioner in a safe, dry, and well-ventilated space. Additionally, ensure the outdoor unit is clear of trees, construction obstructions, and dusty areas, such as a driveway. 

What’s the Maximum Distance Between the Outdoor and Indoor Unit? 

Keep the distance between the indoor and outdoor units as small as possible to facilitate faster refrigerant flow between them. Faster refrigeration cycles mean faster cooling. So, the indoor evaporator and outdoor condenser/compressor should be no more than 15 meters apart.

Can you Put a Fence Around an AC Outdoor Unit? 

Yes, you can put a fence around the outdoor condenser. It helps keep kids, pets, and thieves at bay, thus reducing the risk of damage. Just remember that the same fence can impede airflow around the unit, though. So, you must leave at least one-foot clearance between the fence and the condenser. 

Can an AC Outdoor Unit be Installed on the Roof? 

Unfortunately, no. First, although the roof may seem like a good spot with good airflow, the rooftop exposes the outdoor unit to multiple dangers. For instance, the unit will be directly exposed to sunlight, rainfall, and snow. Secondly, how would you handle servicing? Would you get on the roof every time you check the refrigerant levels or dust off the unit? It’s impractical.


The minimum distance between an AC outdoor unit and the wall is 12 inches or one foot. Your manufacturer may recommend a bigger or shorter clearance depending on the appliance’s airflow requirements.

However, beware that improper clearance can cause inefficient cooling, high energy bills, or even appliance damage.