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Do I have to put an irrigation system for green roof?

asked 2016-06-06 09:59:13 -0500

dana94_08's avatar

updated 2017-05-04 06:11:54 -0500

I am modelling a green roof in OpenStudio (I put the properties of each material constructions) but the results are not logical. I'm wondering if it maybe because I don´t put anything of irrigation.

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What roof construction are you using?

Adam Hilton's avatar Adam Hilton  ( 2016-06-07 07:45:37 -0500 )edit

Plants, Soil, drainage layer, polypropylene layer, drainage layer, roof.

Im putting the materials constructions in that order.

dana94_08's avatar dana94_08  ( 2016-06-07 08:11:43 -0500 )edit

Why do you think the results aren't logical?

Adam Hilton's avatar Adam Hilton  ( 2016-06-07 08:26:29 -0500 )edit

Because the results say the cooling load of the third floor doesn't change. It goes to 1,98 ton to 1,97 ton or less.

dana94_08's avatar dana94_08  ( 2016-06-07 08:46:12 -0500 )edit

Ya, I can't speak to the thermal characteristics you're using for your materials, but with your current setup I think the main things you're not accounting for (and you can't in explicitly in OS to my knowledge) is the evaporative heat loss and your change in thermal mass when you go from saturated to dry soil. Did the object I mentioned in my answer help?

Adam Hilton's avatar Adam Hilton  ( 2016-06-07 09:10:50 -0500 )edit

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answered 2016-06-07 08:33:40 -0500

Adam Hilton's avatar

EnergyPlus has a Material:RoofVegetation object that you should look into. I believe that it captures the effective PC properties from wet to dry soil. You'll have to write a measure to use this in OpenStudio. I don't know much about modeling green roofs, but that object looks fairly convincing and easy to use.

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Asked: 2016-06-06 09:59:13 -0500

Seen: 405 times

Last updated: Jun 07 '16