Earth tubes

[Guest guest]

Quack,

We have been looking at earth tubes

in one form or another for several years. So far, we have no convincing

evidence of their ability to provide cheap, clean air. There is the possibility

of mold problems from spring and summer condensation inside the tubes,

and the difficulty in cleaning these devices. The mold testing has not

been conclusive. The better systems are smooth pipe, sloped, and drained

at their lowest point, but even then you would probably need to run a camera

down them with some frequency to look for evidence of biological growth.

The energy savings have also proven elusive with the fan energy used to

move the air basically equalling the energy gained from the soil. Ground

source heat pumps have a better record for efficiency.

There are many people who promote earth

tubes or who use modelling to show the energy savings. The real proofs

- monitored results and tested clean air - have been harder to find.

Don Fugler

CMHC Policy and Research