When considering wintering your beehives, you need to have a clear understanding of heat, moisture, and air flow; in essence, thermodynamics. Here are a few rules of thermodynamics to keep in mind:
So what does this all mean? This means that ventilation and insulation are key components to successful winterization of a beehive.
For every 40 lbs of honey that are consumed by a honey bee colony, 1 gallon of water is produced and released by the beehive. Through respiration activity of the bee cluster, but also from the release and evaporation of excess water in the uncapped honey cells (relative moisture between 14 – 21% moisture) the honey bees are in constant moisture management. Because of this, ventilation in a beehive is essential to allow the bees to use the heat they produce as well as wing activity to move convection currents and force the air out of the hive through a top entrance, or to have the water condense on the lower parts of the colony where the cool air settles (creating a dew point).
Without proper ventilation within a beehive, mold will form on the combs. This mold is not harmful to your bees and they can clean it up in the spring.
A top entrance for bees is key, as well as sufficient roof insulation. Without an insulated roof, heat will leave the hive as it rises too quickly, and the colony will exhaust itself and resources in an effort to reach a consistent mean temperature throughout the winter months.
A colony of bees consumes the least amount of honey stores when maintaining an internal temperature between 5 – 7°C. When the hive temperature is lower, the colony must consume more resources in an effort to heat the hive. And warmer encourages bee activity and breaking cluster. Breaking cluster causes an increase in the bees metabolism, increases their food consumption and stimulates them to need to go on cleansing flights more often. Therefore it is essential that a beehive is properly insulated in both the bottom board and above the top of the cluster so the colony is best capable of maintaining a 5 – 7°C temperature to decrease times of unwanted heat (breaking cluster) in the depths of winter months, and risking going too cold, and failing as a colony. A well insulated cavity allows for the bees to maintain greater heat regulation.
When wintering double Langstroth colonies, the ability for cool air to pool in the bottom box can be both an asset and hindrance. If the bottom board or the lid of the hive is poorly insulated, the cool air will continually pull energy-heat from the cluster (heat always moves from hot to cold) as well as collect moisture and mold. By insulating the bottom and top of the beehive, you allow for the colony to have a greater control over these concerns by having greater control of the convection currents and the size of the radiant heat pocket surrounding the cluster.
Without proper ventilation or moisture absorption within the hive, condensation can develop above the cluster, drip on to the bees, and kill them.
Are you ready to go more in depth with these topics? Our Level One Beekeeping Course is the perfect opportunity to engage with beekeeping on another level. This course has limited seats so make sure to sign up so that we can notify you when registration is open.