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precipitation for green roof

asked 2017-04-24 14:10:45 -0500

Milad's avatar

updated 2017-08-06 16:20:39 -0500

Hello, I am a beginner in EnergyPlus and I am using Openstudio to model green roof. I am wondering how can I set irrigation and precipitation schedule in Openstudio or EnergyPlus?

Also, if we do not set any schedule for green roof, Does the software consider the precipitation or not?

Thank you so much.

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answered 2017-04-24 15:19:21 -0500

updated 2017-04-24 15:19:38 -0500

Precipitation, sky and, and other environmental conditions that will affect the Material:RoofVegetation will come from the EPW weather file used for the simulation.

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Thank you so much for your response. you mean the software considers rain or snow during simulation, true? Also, do you know how can we set irrigation schedule for a green roof? Also, is it possible to model drainage layer for a green roof in openstudio or Energyplus?

Sorry if I ask so much. Thanks for your kind consideration.

Milad's avatar Milad  ( 2017-04-24 15:42:28 -0500 )edit

Reading the docs for the EnergyPlus object, it is meant to be used on flat or low sloped roofs. so when it rans, the soil should be able to store water until it is at capacity, at which point it would overflow to the ground. I'm not that familiar with this object, but now there are fields about the plants resistance to moisture transport, as well as the soil moisture characteristics. Maybe someone else can point to a research paper or more detailed documentation.

David Goldwasser's avatar David Goldwasser  ( 2017-04-24 15:58:07 -0500 )edit

Irrigation is tricky, I assume you just want to do this until plants get established so they don't die. You could simulate a typical (post irrigation) year, unless you plan for ongoing irrigation all of the time. Otherwise you could alter the weather file (seems like a lot of work) or find a way to alter the soil characteristics on roof to prevent it from every fully drying out, or have thermal characteristics of moist soil). My advise would be to ignore irrigation.

David Goldwasser's avatar David Goldwasser  ( 2017-04-24 16:04:39 -0500 )edit

answered 2017-04-25 10:10:21 -0500

Chris Jones's avatar

An interesting paper on the subject was presented at the esim 2016 conference. ASSESSMENT OF GREEN ROOF ENERGY SAVINGS COMPARED TO CONVENTIONAL ROOF, Ghassem Heidarinejad, Arash Esmaili, Tarbiat Modares University, Tehran, Iran.

The paper is available on the IBPSA Canada website. You need to register first to access the conference papers. IBPSA Canada

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Asked: 2017-04-24 14:10:45 -0500

Seen: 596 times

Last updated: Apr 25 '17