To vent or not to vent?

RangerBrad · August 02, 2011, 08:12:04 AM

With temps being as hot as it has been this summer I have heard two diffrent schools of thought on venting hives in the summer. Some say give them all the ventilation you can while others say that the way bees cool their hive to cause openings in the hive is like leaving the doors open while operating the A/C. What say yal? Thank's, Brad

Francus · August 02, 2011, 09:32:01 AM

I am using screened bottom boards and screened inner covers (basically the screened migratory cover under the hive top) and the bees seem just fine. They still beard on the front of the hive so my guess it's still pretty hot inside!

FRAMEshift · August 02, 2011, 09:42:50 AM

The bees want to keep the brood at 94 degrees. If it's hotter than that outside, I don't see how lots of ventillation helps. I do think that ... at least in the South, it's good to have some afternoon shade on the hives.

Kathyp · August 02, 2011, 10:30:33 AM

i have forgotten what heat is like. :-(

i don't see any harm in cracking the top a little in the heat. BUT, be sure that you have protected the hive from being robbed. i gave an upper entrance to the honey supers for a few days, but had to shut that down with the first yellowjackets. most of my hives are old enough to have more than one entrance anyway....

if you choose not to give an opening, they will be fine as long as they have access to water.

VolunteerK9 · August 02, 2011, 10:33:21 AM

My bees are on their own. Last year was my first with bees and everything that I tried to do to help them only made matters worse. When summer hit and the bearding began, I propped open outer covers, tried screened inner covers etc. Each solution created more problems. The screened inner covers were a waste of money-the bees just propolized them over, the propped open lids started a robbing frenzy, and on and on. I let them beard and fan to their hearts content.

kingfisherfd2 · August 02, 2011, 11:09:12 AM

Last night was the first time that I have seen my bees bearding. Noticed a couple little black marks on my hive this morning when I let the dog out. Walked down and there were a couple little clumps of bees out on the front of the hive still. Figure that they were just ones that didn't get back into the hive last night.

Francus · August 02, 2011, 12:04:36 PM

QuoteThe screened inner covers were a waste of money-the bees just propolized them over,

Even my super propolis making hive hasn't covered the screened top. I think they do it most when light is getting in. Is your top cover propped up? They may make more propolis in that situation.

I did have a problem for a while with them trying to build brace comb from the screened top to the top bars, but after scraping that off a few times they gave that up.

Sundog · August 02, 2011, 01:40:33 PM

I still learning (a lot), but I think Beekeepers seem to be way more particular than the bees about hives. We chew and discuss details of all sorts, and the bees do what THEY want and need. I have seen swarms take up residency in bird house and all kinds of places.

Having said that, I run SBB and a ventilated top. I have a remote temp sensor in the top and I have seen the temp reach 98 degrees. My hives are in my backyard and when it gets too hot, I create an "afternoon shower" (typical in FLA) by misting the area and many of the bees come out to enjoy the "rain", and the temp falls back down to 94 degrees.

Near me there is a very large hive in a tree that has mushroomed way out along the underside of a large branch. It appears to be doing very well. It is on the east side, but I imagine they do a lot of fanning. It is fourty feet up or I would try to capture them. I am going to speak with the property owner about setting a lure nearby.

Have fun!

BlueBee · August 02, 2011, 01:57:15 PM

RangerBrad I don't know the answer, but I also see arguments for both schools of thought. My concern with the small ventilation crowd is the amount of energy imparted into the hive from the sun via EM waves (IR and visible photons). The amount of solar energy projected onto the earth on a sunny day is on the order of 100 watts per square foot. A hive probably has an incident surface area of over 4 square feet. So that 400 watts of heat energy directed at the hive ON TOP OF THE ambient air temp.

Some of that heat EM energy will be reflected by the white paint, but a large amount of additional heat also make it thru. So the bees have to contend with the ???watts of heat from the sun on a sunny day, 90F+ air temps, and the energy they generate fanning to keep cool. Seems like too much heat to me for the bees to effectively deal with. Hence I tend to fall into the bigger ventilation is better crowd.

The problem is the bees are not an infinite energy source; there is only so much they can do. I've attacked this problem by trying to remove the sun load from the hive in the first place. Then all the bees have to deal with are the ambient temps of 90F+. So I'm using foam insulation to block the EM heat from the sun and have gone back to small vents.

Sundog · August 02, 2011, 09:31:48 PM

Does not the brood temperature want to be in the mid 90s for proper incubation?

Have fun!

BlueBee · August 03, 2011, 02:59:17 AM

Yep, brood wants to be about 94F. So why ventilate on a 90F day in Florida since that is below 94F?

The problem is there are other heat sources increasing the temperature inside the hive other than just the ambient air temp. There is heat going in from electromagnetic radiation from the Sun on a sunny day (100s of watts) and the bees themselves are making heat by living (a few watts). All of that heat gets trapped inside a wooden box and turns it into an easy bake oven. The bees have to go into AC cooling mode instead of Heater mode.

It's almost always easier to make heat than it is to make cool. Chemical energy can be converted into heat at high efficiency ratios. However cooling is much less efficient and more difficult to do. It's going to be harder work for a bee to cool a hive by 10F than heat it by 10F. Hence it should be easier on the bees if their hives are on the cooler side of 94F, rather than on the hotter side of 94F.

CapnChkn · August 03, 2011, 03:23:53 AM

One of those things that always left me confused is the metal on the top cover. I was always told they were put on the top cover to reflect heat. Have you ever burned yourself on one of those things? I notice today hives advertised on the Interwebs are covered with Aluminum sheet.

I have one cover Galvanized. The steel absorbs the heat, transferring that to the wood of the cover, then heats the air space above the inner cover, and that heats and then radiates from the inner cover down into the hive. Trees don't have metal covers.

Bees have to compensate for these extremes in temperature fluctuations, and puts them to work on other projects. The Aluminum is a good start, but for those of us who have the old style covers, I save up my Potato chip bags with the Aluminized plastic, tape them together on the printed side and use that to cover the cover shiny side out.

Aluminum will reflect 90% of light, I think. Mylar can reflect as much as 98%. Aluminum foil works, but is made from an alloy and is fragile. During the day touch your top cover, cover it with the mylar and come back in half an hour. You will be amazed.

Since hot air rises, it's easier for the bees to blow the cool air from underneath. I do have some top vents, mostly from feeder holes in the inner covers. Right now with the temps here hovering in the middle 90's (35 C) I have no problem with top ventilation, SBB's, and the heat reflecting up from the white concrete they have their stand on.

No handy photos of the Mylar Cover-Covers, but here's one of the Camo painted Nuc I covered for most of July. SHB really liked being under that film.

Intheswamp · August 03, 2011, 10:22:05 AM

Quote from: CapnChkn on August 03, 2011, 03:23:53 AM
<snip>

No handy photos of the Mylar Cover-Covers, but here's one of the Camo painted Nuc I covered for most of July. SHB really liked being under that film.

Thanks for sharing your experiences, CapnChkn.

By the "film" I'm taking it that you're talking about the potato chip bags?

The SHB liked the area between the mylar and the metal roofing?

Was there an evident increase in SHB after shading the nucs with the wood as seen in your picture or no detectable difference?

Thanks,
Ed

yockey5 · August 03, 2011, 11:40:59 AM

Quote from: BlueBee on August 02, 2011, 01:57:15 PM
RangerBrad I don't know the answer, but I also see arguments for both schools of thought. My concern with the small ventilation crowd is the amount of energy imparted into the hive from the sun via EM waves (IR and visible photons). The amount of solar energy projected onto the earth on a sunny day is on the order of 100 watts per square foot. A hive probably has an incident surface area of over 4 square feet. So that 400 watts of heat energy directed at the hive ON TOP OF THE ambient air temp.

Some of that heat EM energy will be reflected by the white paint, but a large amount of additional heat also make it thru. So the bees have to contend with the ???watts of heat from the sun on a sunny day, 90F+ air temps, and the energy they generate fanning to keep cool. Seems like too much heat to me for the bees to effectively deal with. Hence I tend to fall into the bigger ventilation is better crowd.

The problem is the bees are not an infinite energy source; there is only so much they can do. I've attacked this problem by trying to remove the sun load from the hive in the first place. Then all the bees have to deal with are the ambient temps of 90F+. So I'm using foam insulation to block the EM heat from the sun and have gone back to small vents.

Huh??? You writing a Theseus or what? Would maybe come back down to earth and say this again? lmao

Sundog · August 03, 2011, 12:17:50 PM

Quote from: BlueBee on August 03, 2011, 02:59:17 AM
Yep, brood wants to be about 94F. So why ventilate on a 90F day in Florida since that is below 94F?

Most afternoons in this part of FLA get hotter than 90° in the summer. I have a remote temp sensor under the top and have seen 98° recently. Also, the brood boxes are on the bottom, and we all know hot air rises.

I have aluminum roof flashing on the top. Not so much for heat (although it never gets hot) more to protect the wood from the rain. I keep the top tipped up in front so the water runs off the back and not onto the landing area.

Have fun!

Judy in in · August 03, 2011, 12:25:30 PM

We went through a period of high 90's here. My hives are already on SBB, so I first propped the telescoping cover, and then went to screened inner covers.

Yesterday, the temps were only 92, and forecast for the high to mid 80's. I pulled all of the screened inners, and dropped the lids. I bought a sheet of 2" polystyrene yesterday...will be putting it on one hive early to see the effects.

CapnChkn · August 04, 2011, 01:23:56 AM

QuoteBy the "film" I'm taking it that you're talking about the potato chip bags?

Yepper! Sheet is thicker, Plate thicker yet.

QuoteThe SHB liked the area between the mylar and the metal roofing?

Nope. They don't need to go between the mylar and the roof. They have the outer cover to fuss with. What I'm referring to is the loose cover of mylar I put over the outside of that little nuc. I put them in their hive body, removed the plastic, and watched about a dozen beetles run for "cover." Those were just the ones I saw.

QuoteWas there an evident increase in SHB after shading the nucs with the wood as seen in your picture or no detectable difference?

I suppose you're referring to the painting I covered the whole shebang with. My Mother paints, and throws all the canvases she doesn't want out. SHB aren't really a problem. SHB larvae are. Bee-nuts gave me the vital clue as to why I was having the problems earlier. If they have enough bees to "fill" the hive volume, they can guard it. Generally speaking, that way the housekeepers can find the eggs and discard them before they become the problem.

It's kind of a pain to keep them in a little nuc until they get the numbers up and have workers hatching, but this isn't 1974 anymore. They can't stay in the sun the way you're thinking. BlueBee has already given us the applied physics of the energy converted to heat on a hive, the closer to the equator you are the less atmosphere to filter and reflect the light; the brightness is just a deterrent to the beetle. They seek the dark, moist places to hide and lay eggs. Also to escape harassment from the colony.

The beetles don't just stay away because the hives are in the full sun. They come in and crawl all over them at dusk. I have regular widow screen for my Robber screens, and they would fly in by the butt-load at dusk. So, in my thinking, it's not just one thing or another. It's keeping the hives in a bright place, strong colonies, and not leaving gaps and spaces where they can hide to lay eggs and escape from the colony.

I didn't have any problem with the beetles in the nuc because there were enough bees INSIDE. These pests were outside.

BlueBee · August 04, 2011, 01:42:24 AM

CapnChkn, you are an industrious soul! I never thought of using a potato chip bag as a sun reflector.

An old canvas painting? I know you're in the volunteer state and I know the Vols love orange. Was that orange artwork some sort of Vol painting gone haywire?

So what's your conclusion for the best sun shield? The potato bags, the orange painting, a combination?

CapnChkn · August 04, 2011, 02:07:07 AM

LOL! I couldn't tell you what the painting is. I'll go out and photograph what I've done.

Michael Bush · August 04, 2011, 04:49:10 AM

Just keep in mind that when it's 114 F outside, the bees still need it 95 F inside. How can they do that if you provide so much ventilation that they can't control the temperature? You can have too much ventilation on a hot day. Maybe not at 95F but anything over that you could.