Double-check my reasoning

[JamezF]

I guess most of us know that with a lump hammer and a sufficiently bloody-minded attitude it's possible to wedge twelve Hoffman frames into a National brood box. By that calculation the internal dimension of a brood box parallel to the rails must be close to 12 x 35mm, or 420mm (35mm being the width of a Hoffman side bar in the UK).

I'm thinking that I could put 25mm of permanent insulation at both ends of the brood chamber, leaving 370mm for frames, then put in ten frames and a dummy board which, given that the frames will rarely sit absolutely tight up to each other, would leave a bee space (ish) outside the dummy that the bees won't build comb in. So I'd get insulation in both ends of the brood box plus the convenience of a dummy board for the effective loss of one frame (which is fine given that frames come in multiples of ten anyhow). I could make the insulation removable, but there'd still not be space for an eleventh frame so there seems little point.

Does that seem sane, or have I missed something obvious?

James

 

[Ian123]

I guess most of us know that with a lump hammer and a sufficiently bloody-minded attitude it's possible to wedge twelve Hoffman frames into a National brood box. By that calculation the internal dimension of a brood box parallel to the rails must be close to 12 x 35mm, or 420mm (35mm being the width of a Hoffman side bar in the UK).

I'm thinking that I could put 25mm of permanent insulation at both ends of the brood chamber, leaving 370mm for frames, then put in ten frames and a dummy board which, given that the frames will rarely sit absolutely tight up to each other, would leave a bee space (ish) outside the dummy that the bees won't build comb in. So I'd get insulation in both ends of the brood box plus the convenience of a dummy board for the effective loss of one frame (which is fine given that frames come in multiples of ten anyhow). I could make the insulation removable, but there'd still not be space for an eleventh frame so there seems little point.

Does that seem sane, or have I missed something obvious?

James

Ok I’d have to ask why bother complicating things just use a dummy board.

 

[JamezF]

Ok I’d have to ask why bother complicating things just use a dummy board.

Well, the underlying idea is to insulate my wooden hives, and losing a single frame of brood space from most of them actually wouldn't be a big deal as most colonies are probably more "brood and a half" size than "double brood" in the height of the Summer.

James

 

[Erichalfbee]

Insulate from the outside?

 

[JamezF]

Insulate from the outside?

That's my intention for the sides with the rails because I can fit it between them, but I'm looking for something that's minimal effort to maintain and any other external insulation (on the ends without rails) means issues with the roof.

To provide a bit more background, I know from experience that bees in poly hives do better here than those in wooden hives. That's perhaps not entirely surprising. As I look to the north east from my office window there is absolutely nothing that provides any shelter (for us) from that direction between here and the northern end of the Quantock Hills that I can see about ten miles away. There's actually not a great deal of shelter from the opposite direction either, but at least the winds from there tend to be milder. I have a lot of wooden kit and replacement would be hideously expensive, so I'm looking to provide additional insulation in a way that is compatible with the stuff I already have and doesn't require lots of extra storage outside the winter months.

 

[Newbeeneil]

That's my intention for the sides with the rails because I can fit it between them, but I'm looking for something that's minimal effort to maintain and any other external insulation (on the ends without rails) means issues with the roof.

To provide a bit more background, I know from experience that bees in poly hives do better here than those in wooden hives. That's perhaps not entirely surprising. As I look to the north east from my office window there is absolutely nothing that provides any shelter (for us) from that direction between here and the northern end of the Quantock Hills that I can see about ten miles away. There's actually not a great deal of shelter from the opposite direction either, but at least the winds from there tend to be milder. I have a lot of wooden kit and replacement would be hideously expensive, so I'm looking to provide additional insulation in a way that is compatible with the stuff I already have and doesn't require lots of extra storage outside the winter months.

Laurence at BMH has done similar things with cork insulation. I have used 25mm of PIR externally in the recess on 14x12's plus adding PIR internally to give a 9 frame 14x12.

 

[Ian123]

Hi James I’d question the benefits of half insulating something, insulation works best if it can trap the air or it’s an enclosed area. If you insulated the sunny wall on a hive you could even reduce internal hive temps. I’ve had poly hives for nearly 20yrs and being a builders son(plenty of off cuts) I stuffed polystyrene into nucs in the 80s but I’ll guarantee bees will and do thrive in bog standard wooden equipment. Colonies in wood respond faster to warming spring weather and will start laying earlier, it’s a little later poly hives and the mass of bees benifit from the insulation. There’s bees in many parts of the world in wooden hives that see far colder temperatures than you or I will find in the UK.

 

[Rory Fields]

Hi James I’d question the benefits of half insulating something, insulation works best if it can trap the air or it’s an enclosed area. If you insulated the sunny wall on a hive you could even reduce internal hive temps. I’ve had poly hives for nearly 20yrs and being a builders son(plenty of off cuts) I stuffed polystyrene into nucs in the 80s but I’ll guarantee bees will and do thrive in bog standard wooden equipment. Colonies in wood respond faster to warming spring weather and will start laying earlier, it’s a little later poly hives and the mass of bees benifit from the insulation. There’s bees in many parts of the world in wooden hives that see far colder temperatures than you or I will find in the UK.

It's interesting, and perhaps goes to prove the adage that 'all beekeeping is local', but I've been keeping bees only 9yrs this winter, and only 100 colonies and reasonable numbers for perhaps the past 6yrs, but here in Northumberland, the difference in spring build up between my poly hives (whether maisemore, paynes or abelo) has been noticeably earlier in the spring than in no wooden hives, excepting a couple of WBC's I try not to press into service. Perhaps it's because my home apiary isn't within range of any OSR or agriculture not based around hill sheep, but the difference is usually a good 2-3wks before the wooden (standard nationals) reach the same point. Re insulation, I've tried sone of the SHINS Thorne sell, in my naivety, and I miss the ease of use the filled in rebates prohibit. The surplus from cut-out paynes nuc feeders are a good way to provide insulation on the outer frames but hasn't it been shown in studies that really only top insulation makes a huge difference to the bees chances of coming through winter? Certainly top insulation is always my priority and though probably nobody's perfect hive if we were redesigning the thing entire, nationals, for me, of whatever material, seem to thrive with the additional top insulation. There's a blog on it I saw, way beyond my capacity to understand, might even just have been a David Evans one or perhaps David Heaf gave a formulation, talking about the r values and quoting papers suggesting that only top insulation is hugely beneficial. I could obviously be totally wrong, and I'm interested to hear how many of you bother insulating the sides - I'd thought wrapping etc, just like the need for top ventilation or top entrances in winter, was a US and otherplace concern?

 

[judy12]

Interesting you say that about top insulation. I use 80% wool carpet samples from the local carpet shop. They are exactly National size and cost 25p each, which goes into the charity box.

 

[Erichalfbee]

Interesting you say that about top insulation. I use 80% wool carpet samples from the local carpet shop. They are exactly National size and cost 25p each, which goes into the charity box.

How many go on top of each crownboard ?

 

[Newbeeneil]

How many go on top of each crownboard ?

A rough check would indicate you would need about 15 to equate to 50mm of PIR

 

[inthewoods]

i use carpet underlay it as a backing on it .3 pieces ..thats about one inch in total ..i put the same in
paynes poly eke .never had any problems..

 

[drex]

Better than nothing, but look in skips for PIR off cuts. Is what I did. Kept in roof permanently. Better insulation, stays dry.

 

[madasafish]

Better than nothing, but look in skips for PIR off cuts. Is what I did. Kept in roof permanently. Better insulation, stays dry.

NEVER insulate from inside. When Hive gets crowded, bees excavate insulation at bottom to make more room. I write from bitter experience of home made poly nucs using PIR..
(i fill in Spring )

 

[Garry R]

Better than nothing, but look in skips for PIR off cuts. Is what I did. Kept in roof permanently. Better insulation, stays dry.

Same as me - 25 or 50mm insulation from a skip all year round stuck to inside of the roof. Keep it simple, I knew someone who used a Kingspan box made to go over the whole hive. He taped and sealed the whole thing but still ended up with a soggy mess of Kingspan - likely a small pin prick and of course once the water got in it wicked everywhere and couldn't get out. That, I think, made the hives really cold and the bees did not survive. The cost of a poly brood box is less than the Kingspan to cover a wooden box, No brainer in my opinion, I should add that I have used poly hives since 1977 in Aberdeenshire until 2011 and the same ones in Somerset until now.

 

[Gilberdyke John]

NEVER insulate from inside. When Hive gets crowded, bees excavate insulation at bottom to make more room. I write from bitter experience of home made poly nucs using PIR..
(i fill in Spring )

Don't know what type of hive you have but mot of the popular types have a crownboard between the top of the populated space and the roof so bees don't have access for mining activity

 

[jenkinsbrynmair]

Don't know what type of hive you have but mot of the popular types have a crownboard between the top of the populated space and the roof so bees don't have access for mining activity

although you do still have the occasional cuckoo who leaves gaping holes in the crownboard

 

[Erichalfbee]

A rough check would indicate you would need about 15 to equate to 50mm of PIR

It’s why I wondered. Not much point in putting just one on.

 

[judy12]

Well I put 2 on each crown board - it's very thick carpet and wool is meant to be a good insulator, isn't it? Mind you, I also keep some of my nationals in my uncle's old WBC lifts which, I think, work well as temperature regulators. And they're well-protected from the worst of the weather as they're in a small copse.

 

[drex]

They will all do better with more insulation above the crown board. It is where they lose most heat. On a cool day, just take the roof off and put hand on CB and you will feel the warmth.
Typical insulation value of a carpet is 0.7, of PIR it is 7