Comments on: Why You Should not Over Insulate Your Home

By: frankschulteladbeck

frankschulteladbeck — Fri, 30 Sep 2011 21:37:09 +0000

Yes, I did mean that the heat in the air is rising up. The transmission of heat in a building does occur by conduction, convection, and radiation, which does mean various surfaces have to be a concern. I do suggest that we need to insulate the walls and under the home as my post of 9/28/11 on pier and beam homes describes. With the heated air rising, we do become more concerned with heat escaping through the attic or roof, so that is why we insulate that area to a greater degree. We also insulate the attic to a greater degree, because we are concerned with thermal bridging (in this case heat radiating through framing to the conditioned space below). In the end, we do need to balance insulation with ventilation, and also properly sizing equipment.

By: HotinTN

HotinTN — Fri, 30 Sep 2011 16:04:31 +0000

We have heavily insulated our TN home and while that works great in the winter, in the summer it is difficult to get the humidity and temp right at the same time. Basically, we have done such a good job insulating that the A/C is now oversized and does not run often enough to remove sufficient humidity. It requires a dehumidifier to keep the humidity between 60% and 75%, which is high.

And on the notes that say to insulate the attic, as heat rises, I would offer that hot air rises, but heat radiates, so every wall/ceiling/floor should be as insulated as is reasonable.

By: frankschulteladbeck

frankschulteladbeck — Wed, 22 Sep 2010 15:34:11 +0000

Tom, it does sound like the system may have to be downsized, and it would be nice for contractors to properly inform their clients of the implications of one job on different systems, so other contractors can be called out to prevent the issue you describe. I would love to see homeowners obtain a manual “How to Operate Your Home”, so that they would understand the correlation between weatherization, insulation, ventilation, the HVAC system, and comfort in the home. If we create a tight envelope with more insulation, then the next thing on our list should be to check our ventilation and the HVAC system, right away. Then it would be nice for the homeowner to understand that they should have fans for air movement.

By: TOM

TOM — Wed, 22 Sep 2010 12:28:37 +0000

I have recently done a service call on a home and the house had new blown in insulation and vapor barrier in the entire roof and attic, now the home is sweating around all recessed light fixtures and dripping on the floor. I am going to run a Manual J on the home, should Contractors be notified that when changing the heat load factor the Central Air and Heat loads are changing the Central Air and Heat system. These systems may have to be down sized? Tom.

By: frankschulteladbeck

frankschulteladbeck — Thu, 04 Feb 2010 10:24:54 +0000

Thanks for the reminder Kent. I did forget to mention that fact.

By: Kent Keith

Kent Keith — Thu, 04 Feb 2010 02:14:50 +0000

Another reason to seal around the attic door is that I see many installed near air returns which can cause a negative pressure and pull air from the attic.
Another product to consider is an attic tent. I have a picture of one on my website at:
http://www.fortworthinspector.com/save_energy.html
Kent