An Experiment with Solar powered Hive Ventilator in Southeastern Pennsylvania


The western suburbs of the Philadelphia area (Delaware, Montgomery and Chester Counties) enjoy a nectar surplus generally for seven weeks, usually from May 15th to July 5th. The main sources of nectar are the mature trees of the area: predominantly tulip popolar tulipfera lirodenrum, black locust robinea psuedoacacia, linden tila americana, and holly ilex opaca. While certain arboreta (Morris, Ashwood, etc…) contain significant stands of Evodia cvodia danillia and sourwood oxydendrum arboretum and Japanese Scholar Pagoda trees sophora japonica, nectar from these sources rarely produces as they occur well after the main honey flow.


Fall honey flows have occurred, but rare and unusual events. Intense development of the area has eliminated most of the formerly abundant wild aster and goldenrod. The same homeowners that didn’t want dandelions in the spring don’t want goldenrod in the fall.


In this environment, an attempt was made to evaluate the usefulness and efficiency of the solar powered hive ventilator. This devise utilizes the suns rays to power a small exhaust fan located in a wooden container the same length and with of a standard supper, above the extracting surplus, to generate an air flow from the bottom board up through the brood chamber and extracting supers out the top of the hive. A thermostat wired between fan and the solar powered generator permits the operation of the fan only after the temperature in the hive reaches a predetermined point.


The purpose of the air movement is to speed the curing of the nectar, to reduce the excess humidity in the hive occurring as a result of the curing of the nectar and to reduce or eliminate the necessity of the fanning actions of the bees. Fanning consumes stores and shortens the nectar gathering ability of the worker bee.


To conduct the test, two hives of approximately equal weight and strength were selected and mounted on two platform scales. For the daily readings, which were always taken after dark, the weight of wooden walls, stores and bees and zeroed out and only the net daily increase was recorded. Each hive had been started one year previously form 3 pound packages with Italian queens from Drew Apiaries. Each hive had produced a surplus of approximately sixty pounds the previous season. There was no indication of supercedure or swarming previously.



The plan of the experiment was to place the solar ventilator on one hive (Hive Number One) for a period of three weeks, then remove it and place on Hive Number Two for the following three weeks. This rotation was then continued for the balance of the season for approximately five months, or May through September. The purpose of the rotation was to cancel out any variation that might exist in the productivity of the two populations.


The results of the experiment for the 1996 season are illustrated in tabular and graphic attachments. Generally the test results showed a 22% increase in hive weight for the hives with the ventilation in place. Most of the increase occurred during the height of the main honey flow. Both hives produced a surplus of 75pounds. With the ventilator in place the hive weight was 205 pounds, ah increase of 37 pounds, or 22 per cent over the entire season. However, for the period May 13th through June 21st, were 203 and 158, an increase of 45 pounds or 24.5%.


From this very small sample test of one ventilator, a tentative conclusion follows that the device pays for itself over a three year period through greater honey production and hive is healthier and dryer during the season. This last feature may contribute to a reduction in hive winter losses.


The solar ventilator was removed in October and stored indoors for the winter. Both hives which were treated with Apistan and Terra, brood survived the mild 1996-1997 winter in good shape and will participate in a continuing experiment using four solar ventilators and eight hives for the 1997 season.




I have no interest, financial or otherwise, in the Bee Cool – Solar Powered Hive Ventilator Company, other than the use of their equipment which purchased.

Wlater G. Arader Radnor PA.





Chalkbrood will flourish in humid conditions. (full transcript)





Inventers Comments:

I welcome any organization that would like to do further testing with Bee Cool Ventilators, that use good testing measures like above. (Just contact us at

Gary Stearns Vermont


Note - Since these studies Bee Cool Ventilator has improved dramatically with reports of up to 50% increase with stronger than ever hives. 






Author: Gregory Eurich, University of Vermont.


Subject: Hive With Bee Cool VS. Hive Without


Hive (A) With Bee Cool Prototype,

Hive (B) Conventional Hive.


5-16-95 (May) Weights A=130lbs. B= 75lbs.

Bees were installed and were placed on scales to record weight changes.

Hives were in a row facing south with the hive with out the Bee Cool on the east side. Feeding sugar water and reduced entrance with grass.

The hive with Bee Cool maybe off for a base weight – it is my feeling that changes positive and negative will show up accurately.


5-22-95 Weights A=133lbs. B-86lbs.

Located Queen in both hives. Egg laying is going well in both—low food storage—purchased 10lbs of sugar and fed both hives.

Used a 1:1 ratio of water and sugar by volume.


6-2-95 Weights A=155lbs. B=110lbs.


6-16-95 Weights A=185. B=135.

Both hives doing well. Queens had a good laying pattern in both hives. Fan stop Gary (inventor) replaced in p.m. Larger number of drones in both hives—queen cups in both hives—no royal jelly.


6-23-95 Weights A=200lbs. B=140lbs.

Fan wasn’t working on Bee Cool hive, was able to start again.


6-26-95 Weights A=220lbs. B=150lbs.

Fan not operational—called Gary.


6-29-95 Weights A=245lbs. B=175lbs. 

Fan working, Gary had replaced defective solar panel causing fan not to work, changed to new superior technology (polycrystalline, Monocrystaline).


6-30-95 Weights A=250. B=185lbs.

Added a shallow super to each hive—Gary brought them in this am. They should have been put on a week ago.

The two deep supers of the brood chambers have way to much honey in them—queen must feel crowded—laying is restricted.

Both queens still have good laying patterns and seem to be equal in vigor.

Gary added a ball bearing fan to replace sleeve bearing witch takes more power to start turning.

No clustering at either hive.


7-5-95 Weights A=260lbs. B=190lbs.

Bee Cool working great

No clustering on either hive.


7-11-95 Weights A=270lbs. B=200lbs.

Bee Cool working great but bees bring in nectar at a slower rate.


7-19-95 Weights A=290lbs. B=230lbs.

Added a shallow super to each hive-bees were upset today, may have been to cloudy. Weights before adding supers were A-280lbs B-210lbs.


8-17-95 Weights A=310lbs. B=275lbs.

Added a shallow super to each hive.

Bee Cool Ventilator working great.

The hive with Bee Cool and the conventional hive are dropping in weight. This is normal for this area between summer and fall flow.

Note – the weight with the additional super body equals the total weight of 8-2-95. Found both queens, they are both laying well.


8-30-95 Weights A=300lbs. B=265lbs.


9-13-95 Weights A=345lbs. B=315lbs.


9-26-95 Weights A=350lbs. B=325lbs.

Honey was taken off on this date—three shallows on the hive with Bee Cool contained honey—two shallows on the hive without the Bee Cool contained honey.

At the time I took the honey off the hive with Bee Cool seemed to have increased bee activity and vigor.


The remaining weight of the two hives was equal—weighing the two deeps and one shallow super of each hive they weighed in at 200 lbs. each.


Gregory P. Euric—Manager HRC-UVM 10-2-95 


Honey from each hive was kept separate and extracted—caps drained and the total weight for each hive was calculated. The hive with the Bee Cool (A) had 83lbs in the three shallow supers while the two shallows from the conventional hive (B) had 63lbs of honey.


Because there was an increase in honey yield in the Bee Cool equipped hive it seems as though this devise does have a positive effect on honey production. To be more conclusive there would have to be multiple identical hives managed for several years.


Note-As of 7-28-97 (2 years latter) the Bee Cool is operating well in the field with no maintenance. With no swarming. The past two years I have left the Bee Cool on during the winter with no problems in its operation. 


Summary of Study:

Reg. Hive 63Lbs.

Bee Cool Hive 83lbs.

32% increase, No swarming, Strong hive, Queen Lays strong, Operating well.        




Author: Fred F. Fulton


“Installation of the ventilators was on two single brood hives.

Compared to eleven similar adjacent hives, honey production was 33% greater, with 3 shallow supers versus 4 with the Bee Cool ventilators after 5 ½ months of use. The solar panels and fans worked fine on sunny day, as advertised. No manipulation of the solar panels was necessary after attaching it to the adjusting brackets. No propolis was deposited on the ventilators. No bees were lost due to swarming or disease.”


Fred F. Fulton October 3, 1997







Note - 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