Don't Be Daft Seal The Draft

Spring, summer, winter, and fall your window unit leaks through them all.  Steven Winter Associates conducted a study for Urban Green Council on the energy and emissions costs of window unit air conditioners.  There Are Holes In Our Walls examined real world installations in New York City and concludes that, on average, each unit is the equivalent of a six square inch hole (roughly 39 square centimeters).

In the summer the cold goes out, causing the air conditioning unit to work harder and use more energy.  In the winter the cold comes in, causing the heating system to work harder and use more energy.  Air conditioning units that are removed during cold seasons literally cut the problem in half.  Installing and uninstalling an air conditioner twice a year is a hassle if you are on the ground floor and down right daunting on the second floor and up.

Buildings may require professionals to be hired to do the work as the liability of raining air conditioners to the ground below can be considerable.  The extra expense is one more factor that makes most installations rather permanent.  The focus of the study is on heat loss during winter months.  Just in New York City the six square inch holes add up to an estimated 167,000 square feet or roughly the size of an average block in Manhattan.

The financial cost is approximated at $130 million to $180 million (USD) every winter.  The range is in part due to the energy source of the heating system, gas versus electric for example.  Even if you do not pay directly for the energy cost, we are all on the hook for the CO2 emissions which are estimated between 375,000 and 525,000 tons per winter just for NYC.  Extending these numbers around the globe is down right mind boggling.

The potential financial savings alone should make it easy to eliminate these emissions from the atmosphere.  Even with improved building codes, the installation of a window unit air conditioner counteracts the benefits of double-pane windows and well insulated exterior walls.  The report includes air conditioners installed in exterior walls including non-window units such as sleeve units.

Beyond stating the cost of the situation today, the report goes on to make recommendations.  The recommendations are broken into categories.  The categories include equipment manufacturers, building owners, city councils, and energy efficiency program developers.  Some of the recommendations can be implemented today and some are concepts that can be developed for tomorrow.

Photo Credit: Geoff Parsons