Brood enlargening downward

[Dishmop]

A lot of floor designs are rubbish, but not always for the obvious reasons.
A thin plywood solid floor is one of them.

What about a thick plywood floor?

 

[user 6228]

Dishmop: an inch of air or expanded polystyrene is worth 5 inches of plywood. However if the rest of the hive is plywood, theres not much heat left for saving by the time we get to the floor

 

[user 6228]

"A lot of floor designs are rubbish, but not always for the obvious reasons.
A thin plywood solid floor is one of them."
Could you give more detail on that please?

3mm of plywood is almost nothing thermally , and with the air either blowing straight across the bottom of it or free to convect...

Mesh floors that have the varroa tray slot all the way up to the mesh with the total depth only 36mm ... is another bad idea...

 

[user 6228]

.
Derekm has doomed do many things during his short beekeeping carrier that I cannot take him serious.
.

its not my beekeeping experience i use for determining heat flow

 

[user 6228]

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Floor insulation. Yes, ants love it.

Thin plywood at least stops wind.

A wooden board catch strong mold.

Solid floor is good. 150 kg honey per hive is not bad. But floor does not bring honey.

thin plywood : the inside surface temperature ~ outside surface temperature

 

[Finman]

an inch of air or expanded polystyrene is worth 5 inches of plywood.

my floors are 6 mm ply. Mostly in winter floor has a thick layer of ice, but what then?

In spring hive bottom do not stop brood rearing.

When I open the whole entrance in midsummer, queen rises to second box to lay, and bees use first box as pollen store and as nectar store.
In late summer I reduce again the main entrance and the queen comes down into first box and fills it with brood.

I cannot see any problem in cold floor. The size of ventilation opening rules however.
Or if open too many upper entrances, draft will be too big.
.

 

[Finman]

its not my beekeeping experience i use for determining heat flow

I have enough experience to see heat flow of the hive. And I work according that.




.

 

[BeeJayBee]

I'm currently studying the interaction between floor mesh/insulation and the entrance height width and a depth (see avatar) ,,,

What camera did you use for that photo?

 

[user 6228]

What camera did you use for that photo?

It's not a photo but the results of a computer simulation where the hive and the air surrounding it are divided in to a million cells and the heat and fluid flow equations are solved iteratively for each cell.

 

[Dishmop]

Dishmop: an inch of air or expanded polystyrene is worth 5 inches of plywood. However if the rest of the hive is plywood, theres not much heat left for saving by the time we get to the floor

I was justwondering if there is any difference that a thick plywood floor is the same a a thick wooden floor.

A wooden board catch strong mold.

Solid floor is good.

 

[user 6228]

I was justwondering if there is any difference that a thick plywood floor is the same a a thick wooden floor.

thermal conductivity of plywood is dependent on the constituent woods, so a softwood plywood is going to be a better insulator than a hardwood plywood. So a plywood floor is about the same as a wooden floor made of the same type of wood. but 2 thin pieces of plywood made into a hollow box would be alot alot better.

 

[JEP]

Hi Derekm,
May I ask, when you do all of your thermal simulations what rate of total airflow out of or into the hive do you assume is occurring 1. in typical "summer" conditions and 2. in typical "winter" conditions?
Kind regards,
James.

 

[user 6228]

Hi Derekm,
May I ask, when you do all of your thermal simulations what rate of total airflow out of or into the hive do you assume is occurring 1. in typical "summer" conditions and 2. in typical "winter" conditions?
Kind regards,
James.

The current simulations are in still air with a constant heat input of 20W, measuring the top to bottom temperature profile so i can verify against my real hive experiments, Moving air is the next step.

 

[Finman]

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I have looked the need of ventilation from number of ventilating bees on landing board.

During decades I have seen how it works. No need to simulate.

During heavy nectar flow ventilation is very different. Bees move water from nectar 2-3 litre/day. Hive is hot, and in many cases half of bees stop working and make a cluster on wall.