Is Kickstarter's HVAC Cooling System A Cool Way To Lower Energy Bills, Or Just Plain Shady?

Most air conditioning systems have an outdoor unit called a condenser that cools the outside air and passes it inside. Installers usually recommend it be positioned on the north side of your home, where it is shaded from the sun. The theory being that if it runs cooler, it will be more efficient, resulting in lower energy bills. If a north wall is not practical, many HVAC experts recommend natural shading from trees or shrubs. Unfortunately, unless you buy expensive, full-grown specimens, it will be a while before they're effective. What is always stressed is that it's vital that the airflow to the condenser is not obstructed in any way, which rules out putting many types of barriers anywhere near.

There are numerous creative ways to conceal your air conditioner outside, but not all of them provide shade. One inventor claims to have designed a solution that cools the exterior of the condenser without blocking the all-important vents. It's called the AC Shade. It has a lightweight tubular construction and UV-stabilized PVC mesh. It goes together quickly, without tools, and simply attaches to the top of your condenser with bungee cords. Judging by the hugely successful Kickstarter campaign, a lot of people find the idea very attractive. However, to date, no shades have shipped, so there's no customer feedback. In fact, whether there's any point in shading at all is open to question, so let's take a closer look at what we know.

Air conditioning units aren't cheap, so if you're worried about the cost of replacing one, then the AC Shade seems great. It extends outward like an angular umbrella, so it doesn't block the vents. Images clearly demonstrate it casting shade over condenser units, supposedly making for a 10% reduction in air conditioner bills.

However, there are doubts about whether shading is worth doing at all. Although the AC Shade is a new design, other condenser shading products have been on the market for some time, and their effectiveness has been contested by some experts. The Florida Solar Energy Center rates savings from existing devices at just 1% to 3%. This is partly because a typical household AC unit uses around 170,000 cubic feet of air per hour, meaning it has to draw it from a way bigger area than is cooled by shading. The AC Shade might be more efficient, but as none have been delivered yet, we only have the inventor's word for it.

There's another issue. Shading lowers the temperature of the condenser exterior, but that part isn't in direct contact with the fan, tubing, or fins, so minimal cooling effect is transferred. If anything, the casing is already shading the inside anyway. HVAC experts provide several AC efficiency tips to beat the summer heat, but as independent figures for the AC Shade are not available, how much it might save is yet to be proved.