GREEN Austin Texas

GREEN Homes and Real Estate, events, resources and more in the Austin Texas Metro Area

Lessons in Thermal Mass and Great Insulation

I think it is easier for one to learn a lesson by actually feeling it, experiencing it with their own body and mind. Such is the case with thermal mass. I first learned about thermal mass in the Texas Hill Country near Austin, Texas. I believe it was at Lyndon Baines Johnson’s boyhood home in Johnson City, Texas. It was a very hot Texas Summer day, temperatures were maybe in the high 90′s or so. The old historic home was made of hand hewn large rectangular native stone. I entered the home and felt pleasantly cool. It was amazing! It must have been in the 70′s in there on this hot Summer day. Those massive natural stones did the job! They created thermal mass to even out the temperature extremes.

Now, in 2010, my husband does not understand the benefits of thermal mass or excellent insulation. No matter how much I talked to him he just did not get it. Words just don’t mean as much as experiencing it. So one weekend, when we were out in Buda, Texas previewing a community, I took him to see a home built with foam insulation.  This particular builder always leaves the large HVAC closet open at the top to the attic. You can walk in the closet and look up to see the foam insulation under the roof decking in the attic, so hence, you are in the attic. My husband has been in our typical Texas home’s attic and felt the extreme temperature difference. In the Summer, going up in your typical Texas attic is like walking into a sauna set on highest heat. You start perspiring profusely immediately upon entry. Your air-conditioning duct work has to struggle to deliver cold air through that heat! My husband was totally amazed at the coolness of this attic space. Here it was, a hot summer day in the afternoon and that closet and hence the attic was in the 70 degree range. This is why in homes built like this, the attic is considered conditioned space

Do you have similar experiences? If not, I’d love to help you in your GREEN education. Sometimes it is better to experience it than just read about it. I’d love to show you some homes with thermal mass and or great insulation. I know of homes we can see that are of Passive Solar design and made of SIP construction – Structurally Insulated Panels.  This building design concept of thermal mass protects against the huge temperature swings. Thermal mass is part of Passive Solar design. I also know homes in the Austin area made of ICF construction - Insulated Concrete Forms. ICF combines thermal mass with insulation. It is concrete mixed with recycled polystyrene. I even know of an old historic Texas German settler home currently for sale made of the old fashioned but well working native stone blocks or high-mass masonry walls. I’d love to help you buy your own energy efficient home. Call me, Betty Saenz GREEN REALTOR at (512) 785-5050 or e-mail Betty Saenz

Tags: , , ,

4 Responses to “Lessons in Thermal Mass and Great Insulation”

  1. Laura "Ole" Olesen Says:

    I love the concept of conditioning your attic space. Imagine your A/C unit, without a conditioned attic space, sitting in the attic heat all summer long trying to work to keep you cool. Now imagine the same A/C unit in a protected attic. Much better right?

  2. Jeannie Says:

    I have seen this. I grew up in eastern Oregon/western Idaho for a number of years. Those homes built with cinderblocks were always cooler and pleasant when it was 110 degrees outside and I don’t remember them having air conditioning.

  3. Window Tint Pro Says:

    Thermal mass and maxing out insulation are great for new construction, but in most cases these methods are impractical and not cost-effective for existing homes.

    For most of us homeowners in Texas, the biggest energy consumer in the summer is air conditioning. In addition to making sure their AC systems are operating efficiently, homeowners should also look into installing window tint — especially on south and west facing windows. Window tinting can virtually eliminate solar gain, while reducing energy costs by as much as 70%.

    With increasing energy costs and summers like we’ve had this year, lowering AC expenses may be the best thing we can do to be green.

  4. Pat B Says:

    The application of spray foam insulation directly to the roof decking is an interesting development in the home builder industry. By applying the foam directly to the roof decking, you essentially turn your attic into a conditioned room, thereby significantly reducing the amount of work your AC has to do to cool the living spaces in your home. This type of insulation technique will raise the temperature of the roofing shingles, thereby presumably reducing their lifetime, but I have not seen any data confirming this assumption.I have not yet seen this insulation technique applied to existing homes, but perhaps in time it will be.

Leave a Reply

You must be logged in to post a comment.