I have a sun room that faces east in northern Maryland. I would like to improve its energy performance. What should I do first?

Asked by Dave on the Bay
Chesapeake City, MD

The east and north wall of the sun room have casement windows. On the south side are sliding glass doors. It has a metal roof. When I turn on the ceiling fan there is hot air coming down. Should I use blinds, removable window tint, replace roof with increased overhang?


Paula Zimin

Answered by Paula Zimin

New York, NY

Steven Winter Associates, Inc. (SWA)

June 29, 2010

Your ceiling fan's job is to mix up the air in the room. Air naturally stratifies; layers of air with gradually increasing temperatures, the coolest temperatures at the floor and hottest at the ceiling. 

When you first turn on the ceiling fan, the hottest air above is pushed down to mix with the cooler air. At first, this may be uncomfortable, but after a few minutes the air temperature should even out.

If the mixed air temperature is still uncomfortable, you identified very good and relatively inexpensive options to fight off heat gain, including blinds and window tint.

Shading the windows from the summer sun from the outside is the most effective way to avoid solar gain. Given your location in Maryland, an extended roof overhang would be most effective, if designed in a way to block the intense summer sun, but allow the winter sun in to naturally warm the room during the colder months. Unfortunately, the roof overhang is likely the most expensive option.

Solar window film is likely the second most effective way to deter heat gain, although this will also block out free warmth from the sun in the winter. Interior blinds are great in their flexibility, but are not as effective a window film.

Also consider checking the insulation value of the sun room roof. Metal roof systems work well to deter heat gain. However, if not well insulated, the metal roof system could be a contributor to your sultry sun room.

For more information:

Read Mark Schrieber's "We're adding a sunroom to our home. Can you suggest strategies for natural heating and cooling?" for more information on designing an energy efficient sun room.

Tagged In: solar gain

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