Trees, Evapotranspiration, And Reducing AC Costs

Posted on: 23 May 2016

You do not necessarily have to have the latest, most energy-efficient equipment in order to have the most cost-effective AC system. To be clear, keeping your house cool starts with buying a highly efficient AC system, but you can boost the function of your air conditioner by planting trees, This is a low-tech solution because trees are nature's air conditioner. 

Shade Is Only the Beginning

The sun's UV rays will heat up objects. For example, the sun can heat the shingles on your roof up to 150˚ on a sunny day. Your insulation will stop most of this heat before it gets to your house, but some of this heat will leak into your home and cause your AC unit to run over time in order to cool your home back down. Planting tall trees with a large crown on the south side of your home will help to block some of the sun's rays, which in turn will help to keep your home cooler. Still, the most important way that trees can help to keep your home cool has nothing to do with shade. 


As part of a tree's natural process, trees will release water vapor into the air through its leaves. In the same way that vaporizing refrigerant in your AC system will absorb heat from the air in your home, the water vapor released by the trees will cool the air around your home. The air thus cooled will then settle over your house on yard. Not only will this help to keep your home cooler, but it will boost the function of your AC system. 

Condenser Coil Function

Condenser coils cool the refrigerant running through them by pushing air over them. The cooler the air is that the condenser coils have to use, the faster they can cool the refrigerant running through them. Thanks to trees performing the process of evapotranspiration, your condenser will have a large volume of cool air to push over your coils. The less your AC unit has to work to cool your home back down, the more money you stand to save. 

You might think of trees as just part of your landscaping, and if you don't plant your trees strategically, that's all they will be. However, if you plant trees in a way that they can shade your trees during the hottest part of the day and especially provide shade to your condenser unit, you can save on your AC operating costs and HVAC installation further down the line.