# Foam Re-Use Update

For the last 7 months, we have been including return labels for the packaging foam on most of our whole house fans. The idea was to see if it was practical to ship the engineered foam inserts back to us for re-use. The payoff would be less garbage, and in this case less energy used.

There is a little bit of work required on the customer’s part like packing up the foam and taking it to a UPS drop off. That was our concern. Would anyone bother ?

Not everybody did. Perhaps they recycled locally. Perhaps they want to save the packaging.

At any rate, over the last seven months, we have had a 34% foam return rate, which is actually better than 34%.

Huh? Why ?

See below and take a math lesson at the same time.

 ————-Math Lesson ———- Here is the real beauty of re-use. Once the packaging foam is returned, we use it again, and again, and again… Expressed mathematically, the Effective Re-use Rate = .34 + (.34  x .34) + (.34  x .34  x .34)+ (.34 x .34 x .34 x .34) + .. … until the foam falls apart This is a geometric series, and the sum of the series can be calculated as = .34/(1-.34)= .51 If you are interested in the math here is the solution: S=x+x2+x3+x4+… Now S*x=x2+x3+x4+… , So subtract the two terms: S-S*x = x, which simplifies to S = x/(1-x)

The bottom line is that instead of a truck load of 2,000 foam inserts being used once, they will be used 2,000×1.51 = 3,020 times!
It actually costs us a little bit more to have customers send the foam back, but we think it’s a worthwhile cause !

And… Thanks to everybody who participated.