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Outdoor Unit Air Flow Issues – A Deep Dive

Your air conditioner won’t work correctly if there is a lack of airflow around the outdoor unit. In Winter the unit has to absorb heat from outside to heat the air inside your home, in Summer the unit needs to expel heat that has been removed from inside your home. Without the ability to move high volumes of air from the outdoor unit, your air conditioning outdoor unit will have serious performance issues. Performance can drop over 50% with inadequate ventilation and this is worse when the ambient temperatures are very low and very high. If the outdoor unit is installed close to a fence or wall, the air blows against the fence and bounces back towards the unit. This air recirculates around to the back of the air conditioner unit causing the refrigerant coil to freeze in Winter and overheat in Summer.

Problematic outdoor airflow issues include:

  • Fence, wall or obstruction within 2m of the front of the air conditioner
  • One or multiple units blowing air into the back or side of another air conditioner
  • Multiple air conditioners blowing towards each other (especially if they are offset)
  • Dense trees, shrubs in front of the air conditioner can prevent proper ventilation
  • Rubbish stored behind the air conditioner can hinder airflow
  • Pet hair and dander can clog the outdoor coil, preventing airflow
  • Outdoor units installed on a balcony or within entertaining areas can cause unwanted air blowing on guests

Fence, wall or obstruction within 2m of the front of the unit

The best way to overcome front obstructions such as a fence or wall is to relocate the air conditioner. The new location should be well ventilated and the outdoor unit installed with adequate distance between the front of the unit and any obstructions such as a fence or wall. The specific distance depends on manufacturer specifications but keeping a minimum of 2 meters will ensure no issues. If the cost to relocate the unit is high or there are no locations around the property that are suitable, the only other option is to install a deflector on the front of the outdoor unit. Magnetic deflectors are available and provide a DIY solution that is removable to allow access when required.

One or multiple units blowing air into the back or side of another unit

If two or more air conditioners are blowing into each other, in Summer the hot air from one unit will be sucked into the other unit, causing the front unit to overheat. In Winter, the rear unit blows cold air and the front unit will freeze. As with the outdoor unit near a fence or wall, the best way to overcome other units blowing into your air conditioner is to relocate one or more of the problematic units. If units cannot be relocated to a suitable location, a deflector should be installed to the rear outdoor unit to stop air blowing into the front outdoor unit. Magnetic deflectors are available and provide a DIY solution that is removable to allow access when required.

Multiple units blowing towards each other (especially if they are offset)

This issue is particularly common in apartment, townhouse living and independent living villages. With multiple air conditioners installed close together, often the units are blowing towards each other. If the units are close or down an alley between houses, this causes each unit to blow air into the opposite unit. Both units recycle the other units air and cause freezing and overheating issues, drastically reducing unit performance. If the units can be installed in a better location, this is the best fix. If this is not possible, a deflector installed to both units is required. If only 1 unit has a deflector installed, the unit without the deflector is now ok but the unit with a deflector is still suffering performance loss until the opposite unit has a deflector installed. Magnetic deflectors are available and provide a DIY solution that is removable to allow access when required.

Dense trees, shrubs in front of the unit can prevent proper ventilation

As we have covered above, outdoor unit ventilation is important to ensure correct operation and performance of your air conditioner. If the front or sides of your air conditioning unit is overgrown with trees, shrubs or bushes, it can act like a barrier and prevent adequate ventilation. Ensure the plants are cut back and thinned out to allow airflow from your air conditioner. This can also help prevent bugs, lizards, snakes, spiders and mice from making a home within the outdoor unit.

Rubbish stored behind the unit can hinder airflow

Most air conditioning units installed in Australia will draw air through the coil at the back of the unit and then blow the air out the front of the unit. If there is rubbish such as boxes, tools, cardboard or plastic etc stored behind the unit, the amount of available air is reduced. This causes the unit to freeze in Winter and overheat in Summer. Keeping the space behind the unit clear is a very important factor to ensure correct operation of your air conditioner.

Pet hair and dander can clog the outdoor unit, preventing airflow

This is a common problem, especially with a large, hairy dog living outside. We have often found a mat of dog hair against the back of the air conditioner coil. This acts like a blanket over the coil and dramatically reduces airflow and performance. This can be removed with a dustpan brush or by hand. Ensure you wear gloves to prevent any cuts from the coil. If the hair has become ingrained within the coil fins, you may require a professional clean from the inside out. This is often done with a foam cleaner which expands and pushes the hair outward.

Outdoor units installed on a balcony or within entertaining areas can cause unwanted air blowing on guests

Not all airflow issues affect performance, sometimes your entertaining area is subject to unwanted airflow from your air conditioning outdoor unit. Outdoor units installed on a balcony or within an entertaining area can cause discomfort as unwanted air blows at your guests. One solution is to relocate the outdoor unit to a new location, this is the best way to prevent unwanted air in your entertaining area. If relocation is not possible or practical, another solution is to install a deflector onto the unit and divert the air away from the entertaining area. A deflector can deflect the air at a 45 degree angle, either upwards or sideways, away from your entertainment area. Magnetic deflectors are available and provide a DIY solution that is removable to allow access when required.

In a nutshell

  • Outdoor unit airflow has a massive effect on the efficiency of your air conditioner
  • Outdoor airflow issues are worse when the ambient temperature is very high or low. Often the issue is not noticed as easily during mild weather
  • Most issues can be identified by the homeowner
  • Professional advice is required to relocate an air conditioning outdoor unit or clean the coil from the inside
  • If a unit cannot be moved, a defletor is recommended. Deflectors can be installed DIY, especially our magnetic removable deflector found here

Need help?

T&K Airpower have been working to keep Adelaide and the Sunshine Coast homes comfortable for over 25 years. Air conditioner not working properly? Does your air conditioner struggle on hot or cold days? Is your air conditioner close to a fence? Give us a call and we will be more than happy to help.
September 28, 2023
Mitch, the technician that came out to inspect our unit was excellent. He arrived promptly and conducted a thorough service. The unit on the property was about 15 years old but he found major faults that required it to be immediately shut down at the mains. Drainage tubes propped up on cardboard boxes, sagging in the middle. The fan axle wrapped in electrical wires, and rubber mounts that had delaminated due to friction and heat. He provided photos of everything, and a quotations for repair and replacement. Frankly, Mitch might have stopped the house burning down, and for that, he and T&K get a five star review.
samantha watson
samantha watson
September 14, 2023
The T&K crew are amazing. Special shout out to Nicole for being so friendly helpful, understanding, and a straight up communication Queen. Steve is professional and helpful. We had a few tradies through, because the job wasn't straight forward, they were all friendly, helpful, super polite, and didn't leave rubbish everywhere. 10/10 would recommend.
Evan Hunt
Evan Hunt
September 13, 2023
We have been using TK Airpower now for a number of years to service or repair our reverse cycle aircon. Living out of town you rely on punctuality and professional work. On every occasion our expectations have been more than met. The company offers an annual maintenance service and performance check which in our case has been done by Nathan who has advised of any problems and carried out any necessary repairs in an efficient and cordial manner. We find the service charge when compared to other electrical service companies highly favourable and payable by card on the day. Our trust in the company has been extended to having no hesitation in leaving the service team alone to finish the job when we had to attend to an unscheduled appointment.
Scott “ScottG” Gully
Scott “ScottG” Gully
September 12, 2023
Absolutely fantastic service. I was referred to this business by Mitsubishi as they are an authorised dealer for the brand as I had issues with my WiFi connection. Steve was so accommodating. To the point of after I had contacted them for help he followed up with a phone call and an email with information on how to go about reconnecting the WiFi side of my system. This level of service in this day and age is very rare . I highly recommend this company and will continue to use it in the future for all of my aircon needs. Regards Scott G
Mark Halliday
Mark Halliday
June 14, 2023
Excellent company. Prompt, friendly service.
mike yardley
mike yardley
May 19, 2023
This is the second time we have used TK Air power We find they are professional trustworthy informative and reliable with friendly techs Adam did our job this time and it was a pleasure to have him in our home Thanks Adam and thanks TK Air power Mike Yardley Greenwith
Adam Beecken
Adam Beecken
May 18, 2023
We recently spoke with T&K AirPower about supply and fitting of a new ducted reverse cycle air conditioner for our home, we’ve always had evaporative ducted air-conditioning but never refrigerated. They gave us a few options but we went for the Mitsubishi Electric knowing they’re one of the best on the market, they also advised us adding the Air Touch 5 controller so we can control via an app and also turn on our system prior to getting home. Installation went smoothly, the guys were on time, friendly and communicated well, they showed us how to use the system and cleaned up before leaving. We will definitely tell our friends and refer T&K AirPower to others, Thx Adam and Cindy
Steve Brown
Steve Brown
May 17, 2023
Excellent customer service. Dealt professionally with my insurance company. I would highly recommend. Nicole was a pleasure to deal with!
Grant Cooper
Grant Cooper
April 28, 2023
Very prompt service. Cost less than was quoted originally because the job turned out to be not so difficult.