A friend, a neighbor or a blog may have advised you that putting your air conditioner in the shade makes it more efficient. While other sources tell you, it is a myth and the benefits of shading your AC are quite questionable. What is the truth?
The truth is, IF DONE PROPERLY, studies show that placing your air conditioner in some form of shade can increase the efficiency by 2% to 10%. A well shaded A/C can save money from reduced energy consumption and potentially increase the lifespan of your system. IF DONE IMPROPERLY, shading your air conditioner will do the opposite and could possibly damage the unit.
During the blazing hot days of summer many folks keep their air conditioner on for most, if not all, of the day. This means that the use of electricity in most households can double, or even triple, during summer which of course translates to higher electricity bill. So you want your A/C to run as efficiently as possible for as many years as possible.
Shading your air conditioner can be a practical and inexpensive way to increase the efficiency of your unit for many years to come if you follow this simple rule: DO NOT BLOCK THE AIRFLOW AROUND YOUR AIR CONDITIONER!
Whenever you are considering putting something near, surrounding, or most importantly, above your air conditioner please check the manufacturer’s guidelines. If you restrict airflow around the A/C unit it will severely decrease the efficiency, capacity, and even lifespan. Now that we have that important caveat out of the way let’s talk about getting the most out of this expensive and important system through shading.
DO NOT BLOCK THE AIRFLOW AROUND YOUR AIR CONDITIONER!
Shading your air conditioner can be a practical and inexpensive way to increase the efficiency of your unit for many years to come if you follow this simple rule.
Why Shade Could Benefit Your Air Conditioner
In simple terms, an air conditioning system draws in the warm air inside your house, removes the heat, and sends back the chilled air, creating a cool and comfortable environment. The heat removed from the air inside your living space is then released outside your home. This process happens so many times each day, you may not even notice it anymore.
HVAC professionals are always harping on airflow around an air conditioner because once the refrigerant in your air conditioning system absorbs the heat from in your home and circulates outside to release it, it needs substantial airflow to then release that heat and return to do it all again.
Without proper airflow, meaning allowing the released heat to dissipate from the area around the unit, the refrigerant cannot fully release the heat and circulates back into your home with a reduced capacity to absorb more heat. It is like trying to clean up a spill with a half full sponge. You will get the job done eventually, but it will take longer and be a lot more work!
So, what’s that got to do with shade? Well even if you have proper airflow around your A/C, if it is sitting in direct sunlight for the majority of the day, especially when the sun is highest in the sky, then the air around the unit is going to be hotter and will reduce the refrigerant’s ability to release heat completely.
Now your air conditioner must work harder and longer than it would if it were enjoying a cool, shady spot! Consequently, it is less efficient, less capable to cool your home quickly, and the harder it works the more likely it is to wear out before it’s time.
What Are Your Options
Shading your air conditioner from the full blast of sunshine can be accomplished in a few ways: shading through trees or other plants, structures, or positioning it on the north side of the house.
We will discuss these means of shading separately and determine which one fits your home the best and can give you substantial savings on electricity. Whichever option you choose you will need to determine if the benefits outweigh the costs. Spending thousands to shade or move an air conditioner will not be offset by energy savings! However, there are inexpensive ways to provide shade and reap the benefits.
Spending thousands to shade or move an air conditioner will not be offset by energy savings!
However, there are inexpensive ways to provide shade and reap the benefits.
North Side is the Best Side
We’re not trying to start a turf war, but this is the most straightforward option! The best time to consider moving your A/C to the north side of the house is when you are getting a new unit installed.
If you are planning on purchasing a new HVAC system be sure to discuss placement of the condenser unit, with your contractor. It may add a little to the cost of the installation if it is not where your current unit is placed but it’s still the cheapest time to change its location.
If you are not planning to replace any time soon then on your next maintenance appointment (which should be annually) ask the technician if it is possible to move the outdoor unit to the shady side of your house and how much it would cost. Most companies will provide free quotes even if they are not already there for an appointment and it never hurts to ask. It may cost less than you think!
Nature Wins Again
If you cannot place your air conditioner on the shady side of your house, and truthfully even if you can, making use of trees and plants to provide shade is the best option!
The study, Effectiveness of Shading Air-Cooled Condensers of Air-Conditioning Systems, summarizes the positive effects of shading your A/C with landscaping to 1) lowering condenser inlet air temperature, and 2) decreasing the solar heat directly received by the condenser.
In other words, shading provided by trees keeps the surrounding air and the ground in a much cooler temperature. It also blocks the sunlight that directly hits the air conditioning unit and even the sunshine that enters your home through your windows. All in all, your A/C does not have to work harder than it should when shaded.
Plenty of studies have been published showing the substantial impact of shading using trees and other plants on the energy consumption of households. There were even benefits that ensued from using trees as shade to reduce carbon emissions in the urban setting.
The article entitled The Value of Shade: Estimating the Effect of Urban Trees on Summertime Electricity Use (Donovan & Butry, June 2009) discusses the result of observing 460 single-family homes in Sacramento, California.
Their research reveals that there is a significant impact of planting trees around your house in reducing electricity use in the summertime. Specifically, there is a cutback of a 185-kilowatt hour or 5.2% in energy consumption in houses that utilize trees on the west and south sides of their property.
This conclusion was supported by an earlier 2002 study written by Hashem Akbari of Concordia University with the subject, Shade Trees Reduce Building Energy Use and CO2 Emissions from Power Plants.
His analysis did more than just show the paybacks of using trees as shade in percentages but actual dollars. It states that there are $200 savings related to the benefits of planting each tree in an urban environment.
You may be surprised by this figure, but Akbari’s accredited research suggests that this reduction takes into consideration the savings for your heating and cooling energy use alone.
Granted that there is also a cost in planting and maintaining trees and plants especially when purchasing more mature plants. With creative design you can get some benefit now and even more down the road as your landscaping grows.
By combining fast growing but inexpensive plants such as, tall grasses, bushes, shrubs, or even a thick vine on a trellis, with some small saplings you can provide some shade to your air conditioner quickly. As everything grows you will get more and more protection which will help as energy costs continue to rise.
By combining fast growing but inexpensive plants such as, tall grasses, bushes, shrubs, or even a thick vine on a trellis, with some small saplings you can provide some shade to your air conditioner quickly.
We hate to be redundant but before planting anything please check the manufacturers instructions on how far to keep plants from the unit on all sides and top. As everything grows you will need to maintain that distance through pruning. As wonderful as plants and trees can be for providing shade and reducing energy costs, they can also impede airflow if they enclose the area around the unit too much.
Shading with Structures
If you live in a climate where your choice of trees and plants is limited, you don’t have a green thumb, or you don’t want to wait for landscaping to grow, building a structure could be your best bet.
You can take advantage of a wall or other parts of a building to block the sunlight when the temperature is at it’s highest. Another option is to build an awning or pergola over the air conditioner. Even using a sun shade canopy could provide quick and economical shade!
However, shading with these structures must be done with caution. Most air conditioners sold nowadays release the hot air removed from inside of your house upward. Meaning, any obstruction not at least 48 inches away from the top of your air conditioner will risk recirculating the removed heat.
Another factor to consider is the possibility of increased noise because the structure could serve as a bouncing off surface for the sound waves.
As previously mentioned, spending thousands to build a structure just to provide shade to your air conditioner will not be offset by energy savings. If you are planning a she-shed, garage or other type of structure on your property then positioning it to shade the A/C could be an added benefit!
If an out-building is not in the works then consider an attractive awning, pergola, or canopy. Always keeping airflow and manufacturer’s guidelines in mind before utilizing any of these options (we just cannot say it enough).
What If I Can’t Do Any of Those Options?
If providing shade just is not an option, you do have another way to lower the temperature around your air conditioner. You can use an evaporative or "misting” system that automatically sprays water droplets the size of microns around the condenser. This could also be used in addition to shading your condenser.
Evaporation of water helps in lowering the temperature around your AC. A high-pressure misting system sprays fine droplets of water without drowning the area because they evaporate before hitting the ground.
There are plenty of evaporative cooling devices you can choose from online that are easy to install and operate, and use very little water to be functional. But some of the best are homemade. Here is an example on Youtube:
The Bottom Line
Based on the evidence presented above, we recommend shading your air conditioner from direct sunlight if it can be done economically. It can improve the efficiency of your unit and gain you some savings.
Important Tips To Remember
Mind the clearance
Any method of shading should not prevent the A/C from releasing the hot air. Otherwise, the efficiency would be worse, and the unit could be damaged.
Shading with trees is better
The comparison between shading your A/C through plants or with structures shows that plants are superior in lowering the neighboring temperature in addition to shielding from the sun.
Place your AC on the north side
If at all possible, position your unit to the north side of your home as it is known to stay the coolest all day.
Pair your shading with an evaporative or “misting” system
For optimal benefits, combine shade and an evaporative system. If you can’t shade though using a misting system can go a long way to cooling the area around your air conditioner.