AirScape Engineer's Blog

We get a lot of questions about the ‘R value’ of our damper doors, so we felt that it’s worth going over the basics.

The so called ‘R value’ is denominated in  the units of (square-feet x degree x hour/ BTU). Sounds complicated, but all you really need to know is:

Heat Flow  Q (in BTU per hour) = Area x (temperature differential) / R-value

[For you techies, this formula is valid for steady state, and assumes an infinite plane area.]

Let’s do the math for our whole house fan dampers.  We’ll assume VERY cold conditions in the attic (0° F) and 70° F inside.

Bottom line:  There is not much heat loss through a well insulated whole house fan damper door.  The question that you SHOULD be asking is: “How well sealed is the whole house fan damper door?”

Most residential windows will have R values of 1 to 3. Another question that we get all the time is : “What is a BTU ?”

BTU stands for British Thermal Unit.

1 BTU is approximately the energy released by burning 1 paper match.

100,000 BTU’s make up one therm – that’s how you purchase natural gas, and right now that costs about $1.50

A gallon of gas has about 114,000 BTU.

• Agriculture is a tradition and held in respect
• Compact towns with no sprawl
• No litter or abandoned cars
• Good food and bread everywhere
• No ostentatious “estates”
• Time tested and attractive architecture
• Walking trails everywhere

The picture at right represents some of the contrasts that  we observed on our recent trip to Europe. Outside of the room, you can see a building that is anywhere from 100 to 300 years old. Every window has shutters which have been used for years to keep noise and light out.

In contrast our hotel room (and every hotel room we stayed in) was equipped with modern windows that make North American models look primitive. As expected, the windows open along the vertical hinge, but the cool feature is that with the twist of the handle, they can be made to tilt open leaving a secure ventilation gap at the top.  When closed, the window seals like an airplane door, which makes for almost zero air leakage.  The good seal was further appreciated, considering that the street is about 2 feet from the window.

First of all, Thanks to everyone who responded to our survey of last year’s AirScape whole house fan customers.  We had an amazing 20% response rate, which indicates that you
either love us or hate us – we’ll pick the former

There were a lot of glowing comments, but a survey is not an exercise in self congratulations.  We take very seriously the few people who were unhappy with their purchases.  What we want is to bring to zero, the number of people with unmet expectations.  Our job is to make sure that you get a quality product, but also make sure that you understand the power and the limitations of our particular technology.

Now, for the mandatory post image. Here is the latest map of our sales.  Every zip or postal code that had an AirScape whole house fan purchase gets a marker.  Look at that – the Canadians are buying. So are the Floridians.

The beginning of February marked the one year anniversary of our foam recycling program. In that time we reused or recycled 2412 cubic feet of foam. That’s two tons of waste saved from the landfill! According to wisegeek.com, 60 million tons of polyethylene foam is produced annually world wide. So we have saved .0000033% of the worlds foam polyethylene foam from entering the waste stream. When you look at our contribution as a percentage of the whole it’s just a drop in the bucket, but it’s a start. We know you’re thinking that it’s a small contribution, but let’s look at it in another way:

2412 cubic feet of foam is roughly equal to:

2,038,884  ping pong balls

110,616 Big Macs (our engineers favorite of course)

16,033  12-packs of beer (pairs well with the Big Macs)

9,614  basketballs

or

1  school bus