Hot and Cold Bedroom

My daughter’s bedroom is always colder in the winter and hotter in the summer than the other bedrooms. She has a hatch opening to the attic in her bedroom. Is the hatch the problem and, if so, how do I solve it?

The Expert Answer:

The hatch is definitely a problem and there is an easy fix; but let’s start with a few facts. More energy is lost through the attic than from anywhere else in a home making it the most important area of the home thermal barrier. The thermal barrier is comprised of insulation and air sealing. The attic entrance is a very important component of that attic thermal barrier, but usually overlooked. If the attic entrance is properly addressed, it pays big dividends in terms of savings on heating and cooling costs, preventing a common cause of mold and enjoying improved comfort.

While the rest of your attic is probably air sealed and insulated to an R-30 or higher level (the higher the number, the greater the insulating value), the attic entrance has large air leaks and very little insulating value. The air leaks can be equivalent to having a window cracked open. The area of the attic entrance ranges from 4-10+ square feet and is typically made of either thin plywood or drywall. Plywood and drywall are subject to warping over time, creating bigger air leaks. Contrasted with the rest of the attic, the plywood or drywall provides an insulating value of only R-0.3 to R-0.4 and the attic entrance is located in precisely the right place to cause significant energy loss in both hot and cold weather.

The location of the attic entrance leads to comfort problems. Since it is usually in or near a bedroom, it makes the area colder and drafty in the winter. This is a common reason for the use of space heaters. The cost of using a space heater is far greater than heat from a central heating element. There is another problem with the attic entrance. The air leaks allow cool air from the home to meet the hot humid air in the attic resulting in condensation. Since the condensation is in a dark, hot and humid area it can create an ideal environment for mold.

Attic entrances are now covered in the International Energy Efficiency Code (IECC). This code mandates specific standards that include R-Value to a level equivalent to the rest of the attic, a durable air seal and a protective barrier to prevent loose insulation from spilling into the living space. Any solution should also be lightweight and easy to use when entering and exiting the attic.

There are two basic options to solve the problem- either construct a device or purchase a pre-fab kit. If you choose to build a solution, it requires the right materials, time and skill. You will need plywood or rigid insulation board to build a protective barrier. Depending on the type of insulation board that you use, you will need a 5-9 inch thick non compressible insulating cover. Air sealing has often been accomplished with legacy alternatives such as gasketing or weather-stripping. Unfortunately, the adhesive with these materials, which is essential for maintaining the air seal, is rarely covered by any warranty. Joining or interlocking components create an air seal that is a more durable alternative, is not subject to compromise by warping or failed adhesive and is therefore a more effective alternative.

If you do not have the time or skills to custom build a solution, you can purchase a pre-fab kit that is not much more than the cost of the materials needed to construct a measure.

Here are a few simple steps in choosing an acceptable kit:

• Check the R-Value of the kit. It must be at least R-30. There are a number of kits that have insulating value ranging from only R-3 to R-13. Some try to hide the real insulating value by using gimmicks such as “Effective R-Value” representations based on foil coverings or surface film which do not meet the IECC standards.
• A fundamental way to understand the effectiveness of an air seal is through blower door testing. If a kit creates an effective air seal, it will likely have 3rd party test results for you to read as well as a published warranty. The higher the blower door reduction, the better the air seal; which gives you a greater energy savings.
• Make sure that the kit comes with a protective barrier. If it does not, then you have to include the cost of the materials to build one and the additional time to do the work.
• Also, look for a long term warranty that covers both the insulating value and air seal so it will ensure that your solution will not break or otherwise lose its effectiveness.
• Like any other purchase, it is wise to check that the kit is proven with references from other homeowners that have already purchased the kit as well as expert reviews and endorsements.

If you get an effective solution, it should return your investment with energy saving in two years or less. You get the bonus of a more comfortable bedroom or living area right away.

Expert - Dennis Melesky - www.essnrg.com

May 29, 2009 at 5:02 pm :: Comments to date: