R value of soft wood

In cold 30℉ weather, condensation is seen at the top vent and cloake board entrance. Warm moist air exiting from these locations are 11℉ warmer than the outside air and this resulted in a large drops of condensation and a wet cloake board landing area.  Foam board insulation above the inner cover and R8 Bee Cozy hive wrap enhances condensation outside of the hive - not inside the hive. Compared to home building codes, R8 insulation does not seem large, but this hive wrap is a wind break and equivalent to 6 inches (15cm) of soft wood. This equivalent hive wall thickness is more like a natural tree cavity wall thickness.

insulated hive wrap and cloake board stack

 

In Atlanta, cold 20°F temperatures arrived on Christmas Day and the ensemble of 11 arctic oscillation forecast a large negative downturn. I used these metrics as significant evidence that winter temperatures are here to stay.  Since 2010, I have reused my NOD Bee Cozy R8 insulated hive wraps  and believe hive wraps improved the chance of overwintered bee hive survival. As a lazy (aka stubborn) beekeeper and despite warm winter fluctuations, I'll leave the Bee Cozy on till spring 2021.

Photo shows joined hives - overwintered hive below and a March 23rd spring swarm capture above an open Cloake Board. The bee cozy is designed for 10-frame equipment, so it easily slipped over the Bloake Board without removing 8-frame boxes. 

I'm encouraged to see warm moist air (bee respiration) condense outside the hive at the top vent and Cloake Board Entrance. 

Here are current the hive elements:

• screen bottom board with no counting board insert
• NOD Bee Cozy R8 insulated hive wraps surrounding the May 25 hive reorganization
• inner cover with top notch up ventilation
• two 3/4 inch sheets of XPS foam board insulation between inner cover and telescoping cover
• white corrugated plastic sheet overhang
• concrete pavers on top

condensation on cloake board

52 °F and there's a puddle of something on the cloake board landing area.  I dip my finger into the liquid and confirm the taste of simple water - nothing sweet about it.  Stacking the medium sized swarm atop an overwintered hive creates enough combined warm moist respiration to create condensation. Condensation, common in winter has taken me by surprise in spring.

bomb cyclone

Winter storm Grayson brought cold temperatures to Atlanta, but no snow.  Use this link to see NOAA's satellite image.

Here's a photo of the upside down telescoping cover.  Warm moist bee respiration which left the inner cover notch, condenses on the cold telescoping cover and froze as a white ring.  Click the image for more detail.

17 °F temperatures encouraged me to add the bee cozy hive wrap now.    The hive wrap is designed for 10 frame equipment, so easily slips over my 8 frame boxes and cloake board.   I'm overwintering a tall vertical double stack of hives.   The stack contains a cloake board, where I removed the cloake board's sliding floor leaving its queen excluder to separate the two hives.  I added two overlapping cozys on the upper large stack of boxes and one cozy to cover the smaller lower stack of boxes.

From the bottom up, here are the hive elements at this time.

• screen bottom board with counting board insert removed
• 1 bee cozy hive wrap surrounding 1 deep box and 3 medium boxes 
• cloake board with integrated queen excluder and sliding floor removed
• 2 overlapping bee cozy hive wraps surrounding 2 deep boxes and 3 medium boxes
• inner cover with top notch ventilation
• two sheets of 3/4 inch XPS insulation 
• telescoping cover
• white corrugated plastic sheet overhang
• concrete pavers on top

Winter Storm Jonas, bee respiration and flight activity

Winter Storm Jonas brought 1.8 inches of rain and a dusting of snow to Atlanta.   The bees are not flying this chilly morning, but the inner cover notch is where I'm focusing my attention.   25.5°F outdoor temperature are compared to warm moist air, bee respiration, exiting the inner cover notch.

At the notch, I measured the temperature of three hives as 31.5°F, 36.5°F and 34.0°F using an inexpensive IR thermometer.   This small range of notch temperatures correlate with how I judged flight activity on warmer days.    In other words, the 36.5°F hive flies most vigorously on warmer days. Notice the drop of condensation (not rain) hanging on the telescoping cover.

condensation

Today's 31°F dawn temperature condenses warm moist bee respiration on the outside of the hive. Ages ago, I inserted a 1" slab of Styrofoam insulation beneath the outer cover to prevent condensation inside the hive.  On cold mornings, it's not unusual to discover condensation near the top vent, but wetness near the hive entrance is less common. Only one hive has condensation at the entrance - in warm weather, this is the hive that flies more vigorously than my two other hives.

winter ventilation and pocket IR thermometer

Last year as an impulse buy, I purchased an inexpensive RadioShack Waterproof Pocket IR Thermometer.  This budget gadget has a limited range, so get close to your target when taking a temperature reading.  At dawn I record the top vent and concrete paver temperature.  The paver sits on top of the hive and acts as a surrogate for smoothed outdoor air temperature.  The top vent temperature acts as surrogate for bee respiration temperature.  Imagine this - on cool mornings, the bees are tucked inside the hive, cold air flows into the entrance and screened bottom while warm moist bee respiration exits the top vent - sometimes I discover the warm moist air condensed to the outside of the hive cover - see photo.  

What is the relationship between outdoor air and bee respiration temperature?  During a cool morning, the respiration temperature is greater than the air temperature.  In other words, all graph points (and trend lines) lie above the y= x line.  For example, a dead hive plots on the y= x line.  Bee respiration temperature decreases with decreasing outdoor temperature - this is consistent with air exiting the top vent as a mixture of fresh air and bee respiration.  In other words, the warm bee respiration is diluted by cooler fresh air.

How do the hives differ?  Three hives (Kent, Buda and Pest) are located in a row, but each has a unique amount of shade and access to morning sunshine.

• Pest's third order polynomial trend line respiration temperature is warmer than the other hive trend lines. Probably Pest has the largest bee population. Pest is a 2011 swarm, captured with the help of Cassandra and John. Pest is a powerful force of nature - what Cassandra refers to type A behavior.
• Kent's trend line respiration is less warm than the Pest trend, yet Kent usually flys more vigorously than the other hives. FYI, Kent receives more morning sunshine than the other hives. My range of temperature measurements (Nov 18th to Dec 3rd) contains many stretches where the mid-day outdoor temperature is too low for foraging. Perhaps Kent's interesting sigmoid trend line represents 1) winter clustering in the flat lower left region, 2) typical non-clustered state in the flat upper right region and 3) a sloped line which represents a continuum of changes connecting these end-points.
• Buda's trend line respiration is cooler than the other two hives. Buda is a 2012 spring split. Probably Buda has the smallest bee population compared to the other over-wintered hives.

condensation: outside versus inside the hive

This fall, water was discovered between the telescoping cover and inner cover.  The dawn temperature of  45 °F, thin plywood construction of the telescoping cover and warm moist hive air is a recipe for condensation.  In the morning, I also discovered condensation on the landing board near the reduce hive entrance.

Using 2 pieces of Styrofoam Block 18"x12"x1" from Micheals, a 1" slab of Styrofoam is fitted to the inside of the telescoping cover.  The small bee escape notch on the top side of the brushy mountain inner cover permits some warm moist air to leak from the hive.  See the photo--Now, the warm moist air leaking from the hive is seen appropriately condensing on the outside of the telescoping cover.   Problem solved, I no longer find water between the telescoping cover and inner cover.