About neil

Energy Star Rated What ?

We have always been a bit miffed that whole house fans are not eligible for an Energy Star rating. It was always our impression that the feds were too busy to find the time to recognize and certify one of the best energy saving technologies around. (That’s a Whole House Fan, BTW) So it came as a pleasant surprise, to see that one arm of our government (the GAO Government Accountability Office) was doing its job.

The folks at the GAO submitted several bogus products to test just how carefully the EPA (administrators of the Energy Star Certifcation) examined products and claims. Now, this is where it would be funny if it wasn’t true. Here is one product they submitted:

So that's how you save electricity... make it gas powered ? DUH !
As if this wasn't enough, they also submitted an "Air Room Cleaner". Yes, that is a duster attached to what is apparently a fan/filter unit. (It was also approved.)

What are the lessons to be learned:

  • Make real standards for energy efficiency.
  • Verify performance is to those standards.
  • Fire somebody !

Hats off to the GAO people !  Not so much for the EPA.

See the whole report at: http://www.gao.gov/new.items/d10470.pdf

Heat Flow

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.

Model length width Area (sq. feet) R value Q (BTUH)
1.0WHF 22.5 14.5 2.27 14 11.33
1.7WHF 22.5 14.5 2.27 7 22.66
2.5, 2.5eWHF 22.5 14.5 2.27 10 15.86
4.5WHF 26.5 22.5 4.14 10 28.98

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.

European Observations

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.

Annual Survey

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.

When you have a hammer…

“When you have a hammer, everything looks like a nail”

What a wonderfully simple way to describe much of our world.  I am reminded of this whenever I see people working on the “energy” problem.  Software people clearly know, that if only we wired everything up and monitored our energy use, the rest of the problem would be trivial.  Economists clearly have the upper hand, because they can describe carbon trading as the sure fire method to reduce carbon output,  increase energy efficiency, and still have economic growth.  Photovoltaic manufacturers, electric car builders, and wind farm developers are among the many queuing up at the public feeding trough.

Nothing wrong with any of those solutions.  Just bear in mind the aphorism.

By the way, our hammer is a whole house fan.