Ventilation Studies by Universities World wide.


Bee Research Laboratory, U.S. Department of Agriculture Excerpts taken from Manuscript by W.A. Bruce, G.R. Needham, and W.J.E. Potts. Amer. Bee J. 137:461-63

The Effects of Temperature and Water Vapor Activity on Water Loss by Varroa jacobsoni(Acari: Varroidae)

Dessication is a critical problem for small arthropods, especially mites, due to their large surface to volume ratios (Edney, 1977).
...For instance, if females are particularly permeable to water, then reducing the hive relative humidity for a critical interval may decrease the survival of mites not attached to an adult bee.
...Because of their small size, they have very little excess water to lose before becoming dessicated, and, therefore, are likely to respond behaviorally by seeking a high relative humidity or a new host to replenish lost water.

Results and Discussion

The need to conserve and replenish lost water is critical for many terrestrial arthropods...

Our results suggest that V. jacobsoni females may absorb water vapor from unsaturated air, as occurs for some other acarines (Arlian and Vesilica, 1979; Knulle, 1984; Wharton, 1985). Water loss difference, measured as time to lose 50% body mass was a dramatic 25-fold, at the lowest temperature and highest av (20 C., 0.97 av), compared to the highest temperature and lowest av (34 C., 0 av)...

...Below 50% moisture loss, death occurs rather rapidly and recovery is doubtful...

...These insites should hasten the development of novel strategies for the control of this devastating parasite."  For full transcript - Amer. Bee J. 137:461-63

(Shaparew study)

Tests Show Ventilators Increase Honey Production; Lower Moisture Content


Consisted of.

80 hives with conventional inner covers.

54 hives with honey ventilators


Direct Quote:


Now a few words about external clustering. Nectar gathered by the bees has a short “shelf life”. It will start fermenting unless reduces to honey within a day or so. When the relative humidity of ambient air is at or near 100%, the air will not absorb any moisture, unless warmed up to a higher temperature. Under such conditions some bees move out and cluster on the front wall of the hive.

During a honey flow the bees bring in only as much nectar as they can dry successfully, be fore it starts fermenting. Thus, the bees drying capability becomes a limiting factor. The honey drying air supply through H.D.V.’s allows the bees to dry the nectar faster; therefore they bring in more nectar. This results in additional pollination and better field crops.


It has been demonstrated that the following benefits are directly attributable to H.D.V.’s (Honey Drying ventilators)

·         Increased honey production.

·         Moisture content reduction in honey by about 1%.

·         Improved pollination.

·         Dryer pollen, when used on hives with pollen traps.

·         Substantial and often complete elimination of bees clustering on the front wall of hive.



Increased honey production (by ventilation) ABJ Vol no 8 PG 575-576 1995 V. Shaparew also UVM Study 1995 and other studies show increase.






(Lenski & Seifert)

The Effect of Volume, Ventilated and overheating of Bee colonies on the Construction of Swarming Queen Cups and Cells


Direct Quote:


1.        Experiments were carried out during two swarming seasons to study the effects of increased hive volume and ventilation, as well as that of colony overheating on the construction of swarming queen cups and cells, issuing of swarms and honey yields.

2.        Queen cups were constructed by all colonies, but their number varied from one year to another. Only one cup, out of 10 or 20, was transformed to a swarming queen.

3.        Fewer queen cups were transformed to queen cells by colonies maintained inside large-volume hives (low population density) than by congested colonies.

4.        Increased hive volume and ventilation exerted an inhibitory effect on the construction of swarming queen cups, cells and on issuing of swarms.

5.        Overheating of congested bee colonies significantly affected the early construction of swarming queen cups, cells and their swarming.

6.        Although, non-significant at P < 0.05, the honey yields obtained from colonies in high volume, ventilated hives, were higher than those from controlled colonies.


Overheated hives had 15.5 queen cups per colony, with 10.0 queen cells per colony with 2 swarms.

Controlled hives had 4.0 queen cups per colony and no queen cells also no swarms occurred.



 Optimal internal environment reduces swarming (Hebrew University Jerusalem, fac. Y. Lenski & Seifert 1980)





“Gentle flow of air, egg laying increased.” (University Paris Le Gurgue France 1995 Alteddad Darchen Study 1980.)




 Bee keeping Residence Inst., Rybnoe, Ryazan Province, USSR. 1974 PCHELOVODSTVO 94 (3) : 19-21 E.K> Es,hov




Chalkbrood will flourish in humid conditions. (full transcript)



Chalkbrood is most commonly visible during wet springs. Hives with Chalkbrood can generally be recovered by increasing the ventilation through the hive and/or by requeening the hive. More information.



Nosema is treated by increasing the ventilation through the hive. . More information.





Maintain good ventilation in hive and honey house. More information.




Maximum upward ventilation is also required to evaporate excess moisture during nectar flows. More information.




Measures of ambient temperature and relative humidity correlated to growth of mite populations among different years. Reduced growth rates were probably the result of diminished reproductive rates by varroa mites during periods of hot and dry weather. (Full transcript)





Inventer - Would like to welcome researchers, areas that need to be studied are the effects that Bee Cool Ventilator has on mites and the hive beetle. Also to continue honey increase results and on the latest AC unit that runs 24/7. Also if you have any other studies on ventilation, we would like to post them on this web site. Contact us at



For complete transcripts of studies contact IBRA.



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