From: "Allen Dick" <allend@internode.net>
Date: Sat, 5 Jan 2002 12:34:32 -0700
To: <BiologicalBeekeeping@yahoogroups.com>
Subject: Re: The proper way to calculate temps bees fly?

Very true. The bees conserve heat in the cluster quite well -- when tightly
clustered, and when raising little or no brood.

HOWEVER, as the cluster loosens, and as the area in the cluster that is at
brood temperatures increases towards spring, the cluster heat has more and
more effect on the temperature inside the hive cavity. As the temperature
in the hive rises, the cluster loosens more and gives more heat to
surrounding air. This process feeds on itself and the cluster loosens more,
unless the hive is of a cold or drafty design.

It is at such a time that the design of the hive -- volume, drafts, etc. --
become more important, and hive heating from cluster warmth becomes more
obvious, even reaching the twelve degrees -- and more, above ambient --
mentioned by Dee.

Some beekeepers who winter in doubles reduce to singles in spring to
conserve heat, (and to allow scraping of the one box which is removed).
Brooding bees do best in snug hives.

However, due to the daily expansion and contraction of the cluster and the
sudden population increases that suddenly occur, we always tend to make
producing hives about twice the optimal volume from a heat conservation
standpoint. For many management reasons, we often use even more volume than
that in producing hives.

Nonetheless, judicious and carefully monitored crowding benefits nucs and
small hives.

allen
http://www.internode.net/honeybee/diary/
I imagine most have looked at the informal
temperature study of top insulation presented there?

---- original message ----
> Curious, I checked a hive on a calm 25F. day. I slid
> a probe thermometer thru the top foam insulation that
> I placed directly on top of the second hive body. I'm
> wintering some hives with 2" foam insulation and no
> upper vent, as an experiment and I had expected a
> higher temp inside, but the temp right at the top was
> only about 30F. Bees do generate heat inside the
> hive, but I was surprised to find how little heat
> actually escapes the cluster.