Building a Better Way
School Transportable Classroom retrofit [Manukau Institute of Technology]
Manukau Institute of Technology
is proposing to develop a high performance classroom retrofit. How can transportable classrooms be retrofitted to create a classroom that stays cool in the summer, and warm in the winter? This in response to typical problems experienced at one local school:
We have recently carried out a trial of a number of different methods of improving the internal climate of our primary school’s prefabs. The trial included roof insulation, heat pump, a sun lizard, hurricane hot air vents on the roof….
My thought was that we should insulate all of the prefab roofs, and then look at adding the other options after that, as I have always bought into the mantra of doing the passive heat management first = insulate.
However, these rooms have no roof cavity – they are a skillion roof, so to put insulation in means you have to take the roofing iron off, making it a much more expensive exercise. There are also issues with putting the roofing iron back on without creating leaks. Now we are only looking at
insulating at the time we replace the roofing, which means it is ten-twenty year timetable to deal with the remaining 6 pre-fabs we have.
There must be thousands or even tens of thousands of these prefabs; all the same design. If you could come up with a method of insulating the skillion roofs on pre-fabs in schools, you will have tackled another significant source of energy use – for cooling in summer and heating in winter.
I think they have changed slightly over the decades. The ones at our school are the 1980's or so design with no eave, interior side wall height of about 2.3-2.4m?, pitch 12 degrees or so and aluminium windows that open awning style. I think there will be one at a school near you!
Question: how on earth to insulate/improve comfort in hot and cold environments without it costing $10,000 a classroom (what happens when you have to re-roof at the same time).
Suggested Answers so far:
Fit a false flat ceiling.
But: The finished ceiling height (if it was installed as a flat ceiling rather than any modifications being made to install it as a pitched ceiling) would be about 2.3/2.4m, which wouldn’t work in a classroom sized room – it would be too low for the size of the room (as you’d be aware all rooms have proportions that work; a 7m x 10m room needs a higher ceiling than 2.4 to avoid seeming like a tunnel). It would also mean that the normal practice of putting kid’s artwork on strings across the room would definitely not be possible.
We’d love to apply them at our school, but they would be valuable for that whole (large) stock of pre-fabs throughout the country.
We have recently carried out a trial of a number of different methods of improving the internal climate of our primary school’s prefabs. The trial included roof insulation, heat pump, a sun lizard, hurricane hot air vents on the roof….
My thought was that we should insulate all of the prefab roofs, and then look at adding the other options after that, as I have always bought into the mantra of doing the passive heat management first = insulate.
However, these rooms have no roof cavity – they are a skillion roof, so to put insulation in means you have to take the roofing iron off, making it a much more expensive exercise. There are also issues with putting the roofing iron back on without creating leaks. Now we are only looking at
insulating at the time we replace the roofing, which means it is ten-twenty year timetable to deal with the remaining 6 pre-fabs we have.
There must be thousands or even tens of thousands of these prefabs; all the same design. If you could come up with a method of insulating the skillion roofs on pre-fabs in schools, you will have tackled another significant source of energy use – for cooling in summer and heating in winter.
I think they have changed slightly over the decades. The ones at our school are the 1980's or so design with no eave, interior side wall height of about 2.3-2.4m?, pitch 12 degrees or so and aluminium windows that open awning style. I think there will be one at a school near you!
Question: how on earth to insulate/improve comfort in hot and cold environments without it costing $10,000 a classroom (what happens when you have to re-roof at the same time).
Suggested Answers so far:
Fit a false flat ceiling.
But: The finished ceiling height (if it was installed as a flat ceiling rather than any modifications being made to install it as a pitched ceiling) would be about 2.3/2.4m, which wouldn’t work in a classroom sized room – it would be too low for the size of the room (as you’d be aware all rooms have proportions that work; a 7m x 10m room needs a higher ceiling than 2.4 to avoid seeming like a tunnel). It would also mean that the normal practice of putting kid’s artwork on strings across the room would definitely not be possible.
We’d love to apply them at our school, but they would be valuable for that whole (large) stock of pre-fabs throughout the country.
Replies to This Discussion
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Permalink Reply by Tony Fitzpatrick on -
What about some of the pumped in insulants ? Some of those polyurethane foam insulants have an R value of 9.0 per 25mm of foam. These could be pumped in through a series of holes in the ceiling or soffit.
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Permalink Reply by Werner Eisenhauer on -
Hi All
Recently I needed insulated panels, instead of polystyrene, I used polyurethane panels.
Purpose made would have cost $ 215 per m2 for using Fibriolite as the substrait, and edging in treated timber 30mm thick.
The only affordable panels I could find where sectional garage door panels, 40 mm thick, and alu sheeting on both sides, I choose seconds, which where more affordable too.
And comes in colour.
Regards Werner
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Permalink Reply by Tim Bishop on -
Did anyone read what BRANZ reported about these insulants? They sure sound promising, but i think with moisture trapping issues?
R 9.0 per 25mm sounds like a USA measurement - R9 per inch. They mean R in imperial °Fft2h/Btu. R in SI units, is Km2/W. To convert USA R values divide by 5.67 = RSI 1.6 per 25mm.
-Tim
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Permalink Reply by Tony Fitzpatrick on
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Thanks for that clarification Tim, I always thought it sounded rather high, although I have seen them advertised on NZ sites using the same R9.0 value per 25mm. My house (made in China) has this sort of sprayed on insulation in the ceiling space, seems to work pretty well, and haven't noticed any problems yet with moisture, even when we were running an unflued gas heater earlier in the winter.
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