I remembered Allen Dick and Mr Gustavson debate about
ventilation, moisture and CO2. I read bee-L archives
about CO2 and its so-called capacity to sink in the
hive.

I measured CO2 in two hives both at the top hole
ventilation for wintering and at the bottom. I do not
claim this is a scientific study nor results are
statistically representative. I just offer the results
I had. Take them and explain them as you like.

Those 2 hives are isolated on 6 faces. They are both
on plain classic bottom board. They have no cover but
styrofoam sheet in place with a front face hole for
ventilation. As a result my ventilation type is from
bottom to top. The 1st hive entrance is fully opened.
There is classic entrance reductor on the 2nd. I do
not know if hives present the same population.

I used a Young Environmental Systems Inc 206 Falcon
for CO2 measurement. Since I could not introduce the
whole instrument in the hive I filled Tedlar bags with
air sampled with an air pump and a plastic tube
introduced in the hive at the bottom level or through
the top hole. I then shoot the air from Tedlar bags to
the sample port of the instrument (it was technically
not possible to pump the air from hives and shooting
it directly to the instrument).

Results were as follows:
- outside (ambient): 360 ppm, T=-9C
- 1st hive:
  - bottom: 1,500 ppm
  - top: 6,200 ppm
- 2nd hive:
  - bottom: 2,200 ppm
  - top: > 10,000 ppm

Because of the non direct measurement, I do not think
these concentrations are exactly concentrations in
hives but it seems to me they could be qualitatively
compared.

Hervé
Laval, Québec



___________________________________________________________
Soyez solidaire soutenez l’action du Téléthon avec Yahoo! France.
http://www1.telethon.fr/030-Espace-Relais-Dons/webtirelire1.asp?hebergeur_id=1309