Making and Using a Ventilator Rim

Well, not really making a ventilator rim. I already made it and it looks like this:

My first ventilator rim. (August 2, 2011.)

Like the name implies, it provides ventilation for the hive. And as far as I know, it’s good to have on the hive any time of the year, though for the winter I might stick with my insulated inner hive covers. They worked out well this past winter.

I think the rim is also called an eke, a shim and something else I can’t remember at the moment. But ventilator rim is easier to understand than any of those, so that’s what I’m calling it. And this is what it looks like when I poke my head down inside:

Inside Hive #1 with ventilator rim (August 3, 2011).

The rim is three inches high, one inch thick, and the pieces of wood are screwed together to match the dimensions of a standard Langstroth super. The ventilator rim has holes drilled on every side except the side facing the front — three holes on the wide sides, two on the back.

Drilling the holes at an angle pointing downwards from the inside out would probably help keep wind-driven rain or pooling water from getting into the hive. I’ll try that next time. I also stapled some screen over the holes on the inside. Wind blows through the holes but wasps and other predatory insects can’t get in.

As seen in the second photo, I put an extra medium super over the rim because when I put a telescoping top cover directly over the ventilator rim, it covers over most of the holes on the rim. I’ll make sure to use higher rim next time to make room for the telescoping top cover.

The idea is that heat and moisture building up inside the hive can readily escape through the hole in the inner cover and is then blown out through the ventilation holes. The bees don’t have to beat their wings so much and work as hard to create an evaporating current inside the hive. That means less resources spent on creating honey, which means quicker honey production and more of it. A win-win situation for everybody.

The extra ventilation also makes it easier for the bees to regulate the temperature of the hive for brood rearing. So it’s all good. And in the winter, the ventilator rim supposedly can help prevent condensation from building up in the hive, which makes it a triple whammy of good news.

My hives have been slow to start building in their honey supers this summer, but it’s a different story since I installed the ventilation rims. I can see the bees crowding around the inner cover hole above the honey supers all the time now, which is probably a good sign that the bees are working the honey supers. There could be, and probably are, other factors involved, but providing the hives with better ventilation doesn’t seem to hurt.

August 6th, 2011: I’ve been told since I got into beekeeping that proper ventilation is key to colony health and honey production. I’m curious to see if these ventilator rims make a difference. They’re much like the D.E. Hive design. I suspect the effect of the ventilator rim is exactly the same, only cheaper to make and easier to use. Already it seems the bees are building into the honey supers faster, but that could be coincidence. Either way, I’m excited about anything that might help our bees thrive on this cold rock in the middle of the North Atlantic. At least I don’t think it’s harming them.

February 2019 Postscript: This post has been edited and slightly condensed form its original from (though I was tempted to delete the whole thing). I still have several of these old ventilation rims and I still use them, but I would never build a ventilation rim like this today. They’re just too short. Instead, I use my world-famous Mud Songs Ventilation Rims that are commercially sold as “ventilation boxes.” But to me, they’ll always be my special ventilation rims. They’re also really cheap and easy to make probably work just as well as the D.E. Hive ventilation box system.

A single-deep hive with a ventilation rim installed.

3 thoughts on “Making and Using a Ventilator Rim

  1. The ventilator rim creates an airspace above the top bars and below the cover, correct?

    Do the bees ever fill this space with wax comb during a heavy nectar flow? I would imagine them filling it with comb and honey during our springtime wildflower and citrus flows here in Southern California . . .

  2. “The ventilator rim creates an airspace above the top bars and below the cover, correct?”

    It creates some air space above the inner cover and below the top cover, not technically inside the hive itself. At least that’s my understanding of it. The airflow between the ventilator holes pulls the moisture from the hive. Again, at least that’s my understanding of it.

    “Do the bees ever fill this space with wax comb during a heavy nectar flow? I would imagine them filling it with comb and honey during our springtime wildflower and citrus flows here in Southern California…”

    Good question. My answer is I don’t know because this is my first time using it. I have seen photos of bees building comb in empty supers above inner covers, but usually when packages are installed and the queen isn’t happy with the brood box for some reason.

    Ask Rusty. She might know.

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