Moisture quilts should be dry
Every now and again someone wants to know what happens when my moisture quilts become saturated. One beekeeper wrote, “I can’t believe you keep a soggy pillow over top your bees.”
The short answer is simple. I don’t.
Here’s the issue: if your moisture quilts are soggy, they are not made correctly. Moisture quilts are designed to regulate moisture, not store it. As I’ve said before, nothing improved my overwintering more dramatically that moisture quilts. My hives remain dry inside, the quilts are never wet, and the bees thrive. Since using them, I’ve routinely overwintered 80% to 100% of my hives.
Remember, moisture quilts are not a new concept. They have been in use for decades by Warré beekeepers with great success, and they are easily adapted to Langstroth hives.
Built correctly, moisture quilts never become saturated. Never. In fact, before I tried them for the first time, I was convinced I would have to replace the chips mid-winter. But I never have. I’ve used the same chips year after year.
Here are some important points:
Water vapor from the hive does not condense on the bottom of the moisture quilt—that’s not how they work. Warm water vapor from the bees’ respiration (water in the gaseous state) rises. Still in the gaseous state, the vapor finds its way through the wood chips, moving between and around the pieces as air does. At some point, the vapor reaches the cold under surface of the hive cover where it condenses. That condensation rains down and is collected on the TOP surface of the wood chips—the side away from your bees.
The wooden frame of the moisture quilt contains a number of ventilation ports which allow the wood chips to dry out and also provides a source of ventilation for your hive. At most, I have seen the top ¼-inch of the wood chips become damp (and I live in an extremely wet climate). I can’t actually see the moisture except for the fact that the wet chips are slightly darker than the dry ones.
But humidity varies from day to day. So while the dampness collects on the wood chips during certain combinations of temperature, humidity, and wind, it disappears during other combinations of temperature, humidity, and wind. Basically, the top layer collects and then releases moisture over the course of the winter—some days it is damp, some days it is bone dry. But you never have a “soggy pillow” in your hive. And since the water that does collect remains on the top surface of the quilt, your bees never touch a damp surface.
Another benefit of the chips above the bees is that they provide good ventilation. Since the air must find channels or pathways between the chips, it travels more slowly than if it had a straight shot from the entrance to the ventilation ports. In other words, you get good ventilation without creating a wind tunnel through your hive.
If you want even more insulation, you can make thicker quilts which will slow down air movement even more. The ventilation ports can be restricted to the top of the wood chip layer since that is where the moisture collects.
I keep a feeder rim beneath my quilts in case I want to feed hard candy or granulated sugar. This is easy to do, and since the feeder rim is below the quilt, enough moisture will collect on the feed to make it palatable for the bees, but the rest of the moisture will go up through the quilt and then be caught by it.
The moisture quilt is such a slick system and works so well that if I were selling them, I’d give a money-back guarantee. I have complete faith in them. That said, they have to be built properly. Simply put: if you’ve got soggy pillows, you’re not following directions.