Several factors affect HVAC performance and costs for cooling and heating a home. The age and energy efficiency of the HVAC system, insulation sealing, and exterior structure play significant roles. Regular heating and cooling system maintenance improves performance and reduces energy use. But landscaping, often overlooked, also influences HVAC efficiency.
This article explores how landscaping affects home temperature in summer and winter, and ways to use it to enhance HVAC performance and lower energy bills.
The Impact of Landscaping on Indoor Temperatures
According to the U.S. Department of Energy, well-placed trees, bushes, and shrubs have the potential to save the average homeowner up to 25% on their annual energy bills. The main reason is that landscaping features like these can impact both heat gain and heat loss at different times of the year.
In the summer, you want to use landscaping features to cut the heat gain that the house receives from the sun and lessen the work your air conditioning has to do. In the winter, you can use landscaping to reduce heat loss and increase heat gain, thereby lowering the workload on your heating system.
Trees and bushes can create an effective windbreak during the winter, helping to reduce heat loss. Erecting a windbreak on the sides of the house can assist in maintaining warmth by preventing wind from blowing against the structure and causing it to cool down faster. An effective windbreak can also help reduce your summer AC costs, as hot winds can make a house much warmer.
In the summer months, taller trees provide a great source of shade that reduces solar heat gain, allowing the house to stay cooler. A well-thought-out tree placement can reduce the workload on an AC system by around 30%.
Having shade around parts of your house also reduces the “heat island” effect. Heat islands result from the ground, especially concrete, absorbing heat from the sun. As the heat radiates off the ground, it raises the temperature of the surrounding air. The hotter air then contributes to nearby structures heating up faster. Grass helps keep the ground and the surrounding area cooler than if landscaping rocks covered the ground.
Another way landscaping can help keep your house cooler in the summer is through evapotranspiration, which is the technical name given to the process by which plants release water vapor into the air. All the water vapor released by the plants cools the surrounding air. Vegetation cools the air in its surroundings by about 5 degrees compared to nearby areas, and this cooling effect increases when the vegetated area has shade.
Planting lower-growing trees and shrubs close to the sides of your house can be beneficial during both summer and winter. The reason is that the vegetation creates a barrier between the house and the outdoor air, forming an extra layer of insulation.
The Impact Landscaping Can Have on Outdoor HVAC Units
Also, it affects the temperature in your house, and landscaping can impact how well an outdoor HVAC unit operates. Constant sunlight beating down on an AC or heat pump during the summer leads to a decrease in the unit’s performance and efficiency. If your unit is on the north or east side of your house, where it receives shade during the hottest parts of the day, you don’t need to worry about it. However, if the unit is on the west or south side of the house, it can become a significant concern.
The main issue when the sun is shining on an outdoor HVAC unit is that all the added heat causes the refrigerant to remain warmer, preventing it from capturing as much heat from inside the house. This is another area where the placement of bushes and trees is beneficial, as they provide shade to the outdoor unit, keeping it much cooler. The only concern is that bushes and shrubs can also impact the unit’s performance if they grow too close and begin blocking its airflow. So you should plant them far enough away and prune leaves and branches to maintain at least two feet of clearance around the unit.
Most Effective Ways to Use Landscaping to Boost HVAC Performance
The types of trees and bushes you plant, as well as their location relative to your house, make a difference in their effectiveness. For instance, if you’re looking to create an effective windbreak during winter, the best way to do so is to plant evergreen trees and shrubs along the north and northwest sides of your house. Deciduous trees are a much less useful option for reducing heat loss during winter since they lose all their leaves in the fall. Planting a mixture of taller trees along with shorter bushes and shrubs creates an effective windbreak that blocks most of the wind.
The best option to cut heat gain during the summer is to plant deciduous trees along the west and, especially, south sides of the house, as this is where the house receives the most sunlight during the hottest parts of the day. Evergreen trees are also helpful in providing shade and reducing heat gain in the summer.
The issue is that they will continue to block sunlight during the winter. That is why deciduous trees are the better year-round choice, as they allow for increased heat gain in the winter once they have dropped their leaves, keeping the house warmer.
When choosing which type of trees to plant, you should also consider their shape and how fast they grow. Unless you want to pay a much higher price for already mature trees, selecting faster-growing species is the best option. It is also a good idea to plant only species with shallow, less invasive root systems to prevent the roots from damaging your foundation or your home’s main water or sewer line. When choosing shade trees, you should opt for those that have bushier, more expansive canopies instead of taller, skinnier trees like elms.
Strategic Ground Cover and Mulching
Using ground cover plants or mulch around your home helps regulate soil temperature and reduces heat radiation back into your home. Grass, ivy, and low shrubs cool the area, reducing the load on your air conditioning during the summer.
HVAC Unit Shading
Planting shrubs or installing a trellis with climbing vines around your outdoor HVAC unit can provide shade and improve efficiency. Be sure to leave at least 2 to 3 feet of clearance on all sides for airflow and maintenance access.
Green Roofs or Wall Vines
If applicable, green roofs or vertical gardens on exterior walls can further insulate your home by reducing heat gain through the building envelope, especially on south- and west-facing surfaces.
Proper Drainage Design
Good landscaping can also protect your HVAC system from water damage. Sloping the soil away from the foundation and the HVAC pad prevents pooling water that could damage components or reduce efficiency.
Since 2010, Environmental Heating & Air Solutions has dedicated itself to providing top-notch HVAC services to homeowners in Roseville, Benicia, and the Northern California communities.
For heating and cooling installation, repairs, and maintenance, contact Environmental Heating & Air Solutions today.
