Archive for the ‘Spray Foam Insulation’ Category

R-Value of Foam Insulation and Fiberglass Insulation

To follow up on the previous topic, this blog will be about the relative R-value of spray on foam insulation compared to fiberglass insulation when they are tested in high temperatures.  This coincides nicely with the previous blog. I want to make one side note before I continue with this blog.  I’m an insulation contractor, so it might seem odd that I’m talking about faults and or short comings of different types of fiberglass insulation.   But no matter what industry I have worked in, I’ve always believed that educating people was the number one priority.  I’m writing these blogs in an effort to educate people on the benefits of foam insulation.  Being an Austin insulation contractor we receive a lot of questions like “why is spray in foam insulation better than fiberglass”, “what is the difference between blown in fiberglass and foam insulation”, “why is the spray foam insulation R-value lower than fiberglass batt insulation”, as well as a variety of other questions regarding insulation.  So, I write these blogs to create a resource to send my customers to in an effort to educate them.  Also, in the end, I think all insulation products can provide benefits in certain situations, but my goal is to identify the differences, advantages, benefits and disadvantages of different types of insulation. Alright, lets get back to the topic at hand.  If you haven’t read the previous blog, read about the R-value test because I will reference it in this blog.  When the R-value test is performed the testing room temperatures are moderate, somewhere between 70-80 degrees.  However, most of the time wall cavities as well as attics (as discussed in the last blog), reach temperatures much higher than 70-80 degrees.   Once temperatures reach over 110 degrees the relative R-value of blown in fiberglass insulation starts decreasing.  As the temperature rises above 110, the relative R-value continues to decrease.  The relative R-value can decrease up to 50% if there is a large enough temperature difference.   Depending on the wall construction it is very easy for the temperatures in wall cavities to reach over 110 degrees […]

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Spray Foam Insulation R-Value

*Warning*- This is a series of blogs regarding R-value of insulation and Air Barriers in reference to different types of insulation.  The first blog will be about R-value of different insulation types.  There are a lot of comparison of spray foam insulation R-values to fiberglass, or blown in fiberglass insulation R-values.  Unfortunately current R-value test don’t accurately compare spray in foam insulation to fiberglass insulation or the like.  For brevity sake, going forward, we will consider the following as interchangeable; fiberglass batts, blown in fiberglass ad fiberglass blown-in-blankets (BIB’s). Conventional R-value testing for both fiberglass and spray foam insulation test how long it takes heat to pass through each medium.  The conditions are perfect, there is no air flow in the testing room, simply a heat lamp on one side and a thermometer for temperature testing.  Unfortunately there is no condition in residential construction that emulates this testing facility.  So here is how the testing fails to compare fiberglass insulation to spray foam insulation.  Say the same test mentioned above is performed, but this time, air flow is added to the testing room, instantly the “relative” R-value of fiberglass insulation decreases by approximately 50%.  Because fiberglass is not an air barrier, the flow of air more or less “pushes” the heat through the fiberglass insulation at a faster rate than if there was no air flow. On the other hand, if the R-value test is performed on spray foam insulation and air flow is added to the test, the “relative” R-value of foam insulation does not decrease at all.  The reason that the “relative” R-value of spray on foam insulation does not decrease is because once three inches of open cell spray foam insulation is applied it creates an air barrier. In most modern home designs with conventional blown in fiberglass insulation in the attic, ridge vents as well as soffit vents are installed.  These vents are installed to create air flow in the attic in order to decrease the temperature in the attic.  While it’s a good idea to decrease the heat in the attic, the air flow supplied […]

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Benefits of Spray Foam Insulation for the Texas Heat!

Spray foam Insulation is perfect for the Texas heat because it helps keep the cool in and the heat out. Benefits include better filling of gaps and voids and more efficient restriction of air-flow compared to fiberglass insulation. Areas that have wiring, plumbing and open floor webs are much more effectively filled than batt or loose fill insulation. Foam insulation has the highest R-value or the ability to slow down thermal flow. Spray foam insulation has as much as two times the R-value of blown fiberglass insulation.  Since the thermal air-flow is reduced, cool air will stay inside and the hot, Texas air will stay outside! Spray foam insulation is much better than other types of insulation because it provides a much more comprehensive covering. It is a more uniform and consistent heat barrier compared to fiberglass and cellulose insulation. Foam insulation’s superior sealing ability enables the attic to be air conditioned providing further relief no matter where you are in your home! A spray foam insulated roof also minimizes air leaks in the attic reducing heat transfer and air duct leaks. Spray foam insulation also reduces all types of heat transfer, radiant, convective and conductive, resulting in more efficient and less costly air conditioning! Spray foam insulation also reduces air conditioning costs. On average, structures with spray foam insulation cut their air conditioning costs by 1/3 to 1/2. Compared to other types of insulation, structures with foam insulation require smaller air conditioning units. This means less costly air conditioning unit purchases, installation and operation costs.  

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