Are Shafts to My Attic Energy Efficient?
Any break in you insulation allows for a great reduction in your energy efficiency, but you may not realize it, there could be a good number of breaks in your attic insulation.
Maybe I have been writing a bit too focusedly on attic insulation lately; however, a couple of home inspections over the last week have made me consider how we build our homes. There are times that I think that I should take a gymnastics class to help me better move through attics. One danger is a shaft going down into the home from the attic. You may have one in your home. Metal fireplace flues, air conditioning systems in a closet, and lower ceiling spaces are the main culprits. These shafts are framed out to allow for the flues or lower ceiling, but frequently the walls in the shaft are not insulated, and insulation cannot be placed over the gap. Gaps in the insulation are great for allowing the heat or cold passage into your home.
This concern first developed while I was dangling over a large shaft for a metal flue in a two story building. A wide shaft was created because the flue angled at 45 degrees to meet up with a brick chimney to exit the home. Finding footings so I could jump across to the other side was not easy. With feet and hands occupied, I held my flashlight in my mouth, then I looked down. This large gap went down to the first floor. The gap was 5′ by 4′ by 20′. I did not think about falling; I thought about 360 square feet of uninsulated walls. Insulation has to be kept away from the flue itself due to that situation being a fire hazard, but the walls could be insulated. I have never seen a builder insulate this space.
In another home, I spotted an unusual shaft coming down from the attic, which caught me off guard. There was a closet in one room, but the back wall of the closet did not quite meet up with the wall from the room next to it. This was a family room with an angled wall to create a more dramatic space below. This led to a gap of 1′ by 4′ by 3′. Not as large of a space as for the flue, but still a problem for energy efficiency. Typically I see shafts above lower ceilings for showers or in kitchens, and sometimes people remember to insulate these spaces, particularly if they are large. Smaller lower spaces, like this closet, are not insulated. The builder could have placed insulation over this and similar gaps, but this does not always happen.
A common shaft occurs when the air conditioning system is placed in a closet in the home. Actually this set up could be highly efficient. If the AC system is in a conditioned space, it has to work less. In this case, the gas furnace for the heater needs air for combustion, and it has a flue for the exhaust gas. With the flue, we have the same problem as with the fireplace flue: keep insulation away from the flue due to fire concerns. This poses more of a problem if we wish to create a really efficient system. Insulating the shaft as mentioned for the fireplace flue is easy, but then we loose the efficiency of having the system to work less. If we close off the opening in the attic, we loose the air supply for the burner. (An electric heater would resolve this concern, but gas heaters are preferred by the consumer). If we install an air supply tube to the burner, while bringing the flue through a ceiling in a similar way as we would with a water heater inside the home, we can create a better insulation situation. This is not done. Again, builders do not think about this efficiency issue.
Alright, I mention that builders do not do these steps, but this does not mean that current builders are not concerned about these issues. Currently built homes by most builders do have “green” features. I say “green”, because this term really is a catch-all for several items. Most builders focus on energy efficiency, but few give thought to sustainable or water conservation. However, we still have a way to go. I am really worried about older homes. The building industry has concentrated on new construction when considering eco-buildings. We need a program detailing best practices for green remodeling. Hopefully, home inspectors will be included in the conversation, since we see what happens to homes over time. Home inspectors need to really speak up on this matter though. Architects, builders, engineers, and others will not listen to us, until we make our voice heard; the industry will have a great loss, if they do not tap into our knowledge.
« « What Are the Components of a Greywater System?| New Ways to Hide Defects When Selling a Home » »
