hot tin roof

[user 6228]

I measured the outside surface temp this afternoon of a poly roof and got 31.2 C

The underside surface was 3 degrees cooler, and this was consistent over a sample of three.

PH

PH interesting What colour /paint finish was on the sun side?

For those interested in the theory "Fundamentals of Heat and Mass TRansfer" is a good read (pricey)

For interested the practical.: try sitting in a wooden shed in a hot summer
Did that in southern Germany for two years... Not that pleasant - good excuse to go the beer garden though

I have a complete redundant wooden hive that i could measure the heat gain using my new temp measurement frame. Unfortunately I have only a part of spare poly hive to compare it to.(the bees still have the matching floor)

 

[oliver90owner]

I just put insulation under the roof. Job done.

I quite agree. All my new home made roofs have 25mm expanded polystyrene just below the ply which is directly under the metal sheeting. Any air in the roof space will be a hugely efficient insulator as regards any heat conduction.

The results quoted in isolation above are relatively meaningless (apart from them being polyhives) as the brood nest will need to be maintained at near 35 degrees, evaporative losses (as they reduce nectar to honey) will consume oodles of thermal energy (over 2000 Joules for every gram of water evaporated) and they will be circulating the air in the hive as part of their air-con system to remove those large volumes of evaporated water (each mole of water [18 grams] as an ideal gas, would occupy over 22 litres at standard temperature, let alone at an elevated temperature in the hive).

 

[E1M]

Just put a cat on it.
You will soon find out which is hottest!!!!!!

 

[REDWOOD]

I need a roof that cooks the earwigs inside my roofs, annoying little critters

 

[Poly Hive]

The paint was vinyl emulsion and the colour was mushrom and or err... magnolia...LOL

PH

 

[lancee]

Sounds like an ideal location for a rooftop solar panel or two !

 

[TBRNoTB]

Ours are all green, so those using the evil eye of the online arial mapping services have a harder job spotting them.

Slightly of track (well a lot) saw a google camera car today with a golf ball type camera strapped very firmly to the roof, thought they had packed all that in! obviously not!