roof vent

[asif.shamim]

Hello Everyone!

 I am working on project where i have to integrate ventilation into the roof in order to reduce thermal needs of the building.

i modelled the building and then i put roof vents on top of the roof. i dont know if thats the right way of doing it. i have to do energy analysis of the model in openstudio i dont think gbxml file will export the vents along with roof too. 

can someone help me please. 

[barthbradley]

Roof vents have no impact on energy analysis.  

[asif.shamim]

ok. in the task its mentioned that integrate air ventilations into building roof in order to reduce thermal needs of the building. how can i elaborate the reduction in thermal needs of building after roof ventilation?

[ToanDN]

Shouldn't your energy analysis program have check boxes to check this stuff for it to calculate?

[asif.shamim]

i am using openstudio for energy analysis. it exports the material that element is made of. in case of roof, the roof vent is on top of it. in simple words, when i select roof, only roof is highlighted and vents are left behind. that means vents are not part of roof. so gbxml file wont be able to read it. 

[RDAOU]

@asif.shamim 

This is not really a Revit question...you need to refer to OpenStudio and Energy Plus user documentation

A Roof Vent is an insert (ie: the roof is exported with an opening). Literally speaking Openings are holes in the roof that allow air through => Technically speaking, they do not really have any significant thermal properties (ie: no heat transfer properties). Their impact on the energy analysis is

1. either considered as an increased infiltration/ventilation in the attic thermal zone/volume
2. or simulated as Wind and Stack Open Area

If such vents also have covers ... then they would also be taken into consideration under the Building Envelop calculations a part of the skylights/roof ratio.