Forum discussion

NC-2009 IEQp1:Minimum IAQ Performance

iEQpr1 Operable awning windows for natural ventilation

Hello, We have a building that is naturally ventilated and to comply with ASHRAE 62.1-2007 (prerrequisite) we are planning to place operable windows. We made the calculations to get the open area needed. The question is: since the considered operable windows are "awning windows" with a 25º opening angle, do we have to consider a certain (reduction) factor or can we take the gross window area for this calculation?

1

You rely on LEEDuser. Can we rely on you?

LEEDuser is supported by our premium members, not by advertisers.

Go premium for $15.95  »

Wed, 05/23/2012 - 22:02

FROM ASHRAE 62.1-2007/ 5.1.1 Location and Size of Openings. ...Where openings are covered with louvers or otherwise obstructed, openable area shall be based on the free unobstructed area through the opening. Coordinate with Controllability of Systems, Thermal Comfort, which allows for naturally ventilated space: "Operable windows may be used in lieu of controls for occupants located 20 feet inside and 10 feet to either side of the operable part of a window."

Wed, 05/23/2012 - 22:18

Thanks Hernando! But for these operable windows, what is the gross opening area that should be taken into account, considering that the open area is not obstructed as a louver is and air can still go in through the whole area of the open window.

Wed, 05/23/2012 - 22:29

The intent of the ASHRAE 62.1 requirement is to prevent the frame element from being claimed as a ventilation opening. Also, to prevent the full area of a operable slider window from being claimed.

Wed, 05/23/2012 - 22:33

Perfect! That pretty much clears it out.. Thanks for your ultra-fast response!!

Tue, 07/22/2014 - 19:32

Hernando, I may have the same case they posted here, but my opening angles could be even smaller, since its a project of 30 above grade floor levels with operable windows at every level. I did not fully understand your explanation. Can I claim the 100% of the awning window as open? How will I calculate the reduced percentage if not? Thank you in advance.

Add new comment

To post a comment, you need to register for a LEEDuser Basic membership (free) or login to your existing profile.