Sunday, October 23, 2011

Insulated Moisture Quilt

      One of the major reasons for winter loss of honey bee colonies in cold climates is cold, moisture dripping on the cluster of bees.  The moisture is created when the warm air emitted from the cluster of bees rises and contacts the cold surface of the outer cover, creating condensation. 
       Winter bees are produced at the end of the summer. They are physiologically different from summer bees with a different blood protein profile and fatter bodies with the specific purpose to survive until spring.  Once the temperature drops below 14 Celsius these winter bees begin to form a cluster within the hive.  The bees on the outside act as insulators with their heads pointed towards the center of the cluster.  On the inside of the cluster the bees move their wings rapidly and the friction of this movement creates heat.  The centre of the cluster, where the queen resides is approximately 32 degrees Celsius.  As the heat rises the bees in the middle of the cluster move outward to become insulators and the outer bees move inward to become heat generators.  This movement of bees is continuous throughout the winter.   

       With the Insulated Moisture Quilt installed the warm air from the cluster rises up through the quilt contacting the less cold, insulated surface.  The reduced condensation that is formed will drip on and be absorbed by the wood chips.  The air vents will dry the wood chips.   
        To build the Insulated Moisture Quilt you could simply use a medium or deep super but for those like myself who like to build things here is a step by step description using scrap material.  First I screwed together some 6 inch wide 3/4  inch plywood (any 3/4 inch dimensional wood would work) to create a box that would fit on a deep super. 

   Then I screwed in 3 pieces of plywood 3 inches high. 

       I stapled landscape cloth (porous) over the bottom of the quilt box.  More durable alternatives to landscape cloth are window screen or 1/8 inch hardware cloth.

The 3/4 inch vent holes were drilled 2 inches above the landscape cloth.  Hardware cloth is applied over the vent holes to prevent entry by bees or mice.

       On the bottom I screwed on an optional 1 inch frame so the bees don't attempt to join the frames to the quilt surface.  The extra space will allow for pollen patties or sugar feeding in the early spring but could be replaced by a candy board between the quilt and the super to prevent comb building. This space could be modified or reduced to be more in line with proper 3/8 inch bee spacing.  I don't find this much of a problem for me as the quilt is primarily on when there is little or no foraging and wax burr comb creation.  Note the upper entrance chiseled improperly on the side of the eke.  I repaired this and added a front upper entrance.

                                                     Two inches of wood chips are added to absorb the moisture.

                            I added a 1/4 inch plywood cover with stapled rope for easy removal.                                 

        2 inches of solid insulation is added. It's a good idea to paint the finished project for weather protection.                   

Winter hive set up with 2 inch feeder and insulated moisture quilt

      Another way to combat the winter moisture issue is putting a 2x4 under the rear of the hive so that the condensation formed on the underside of the outer cover runs down the front of the hive instead of on the cluster.  Also an upper entrance is recommended to increase ventilation. Here are a few different quilt designs and a downloadable version of the Insulated Moisture Quilt: A non insulated Langstroth quilt;  A quilt using wool as the absorption material; and a Warre Hive quilt.  "The Biology and Management of Colonies in Winter" describes the temperature and moisture dynamics that occur within the hive in cold climates during winter.   For more information go to the Beekeepers' Library and scroll down to "Winter Management".        
      I received a World Wide Patent on this design which stipulates that anyone who uses this design must give me a jar of honey.  What can I say it's the law.  All honey related patents in Canada are strictly enforced by the C.H.P. (Canadian Honey Police), Chief of Police Winnie (from Winnipeg) T. Pooh.

Chief of Police


  1. I don't think you're getting any honey from the chief of police.

  2. Very nice. Is that a "World Wide Patent"? I'm in the U.P. of Michigan, USA. Any jar of honey I would send would have to go through customs, but due to N.A.F.T.A. there will be no tax.


  3. Yes Bob it is a World Wide Patent but no need to send the honey, our Chief of the Canadian Honey Police will pick it up. Only give him one jar, he will ask for more (he has a weight issue). He's a tad chubby.

  4. 2 jars of honey on it's way! keep in mind these are very small jars, don't need trouble from your pesky boarder people..... Bee brother from south of you.

  5. Thanks you. Much appreciated. You can never have too much honey.

  6. Danielle, I adapted your insulated roof idea by combining it with a gabled roof plan by Bill I owe you both a half jar of honey!

    How did the design work out over the winter? I am putting my own insulated roof in for the first time and am interested in how you would modify or not.

  7. The insulated moisture quilt worked well last winter (a particularly cold, wet winter). I was a little worried about using landscape cloth but it held up well (no deterioration). I also thought the gabled roof would work in combination with my insulated moisture quilt but I cover my hives to protect from the heavy winter wind and rain (2x4 and poly) so the gabled roof would just work as an asthetic improvement. I'm glad you improved my design. Good luck.

  8. Four years later... Is this design still holding up? I'm wondering about the 1 inch frame. Don't the bees try to build comb in that area since it's larger than the bee space (3/8 inch)?

  9. The original box has held up but most beekeepers use a 1 inch medium super. Yes the space can be modified to the 3/8th inch bee space but for the 5 months the quilt is on (November-March)for us there is little nectar or foraging until March when many place a candyboard between the quilt and super eliminating the extra space.


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