attic ventilation

[leyi123]

Hi Chief! (I am using X15)

I am trying to work on two parts about attic ventilation:

1. draw the vents

2. do the calculation (attic area, vent area, 1/300... etc.)

 

So my question is - is there built-in functionalities about these? I searched and searched and didn't see much things useful. I found gable vent in library, which I may use. But I can't find soffit vent referred anywhere from "Help" or library, how do I specify that I want to install vents along soffit? and have the area calculated? Do I need to just draw polyline for those and manually do calculations?

 

thank you so much!

-Leyi

[Renerabbitt]

8 hours ago, leyi123 said:

Hi Chief! (I am using X15)

I am trying to work on two parts about attic ventilation:

1. draw the vents

2. do the calculation (attic area, vent area, 1/300... etc.)

 

So my question is - is there built-in functionalities about these? I searched and searched and didn't see much things useful. I found gable vent in library, which I may use. But I can't find soffit vent referred anywhere from "Help" or library, how do I specify that I want to install vents along soffit? and have the area calculated? Do I need to just draw polyline for those and manually do calculations?

 

thank you so much!

-Leyi

Preface to say what you are asking for requires very advanced methods which is why you may not have found much on the subject. Some people build a simple tool for a solution which only handles particular use cases. Might be more useful to just use a calculator

For a holistic approach that covers most if not all aspects of a programmatic result for nfa requirements, I think there would be some sacrifices somewhere down the line. 
In a perfect world we don't need global macros, but you likely do for this task to be done and working for all scenarios.
Here are a few things to note:

• A roof plane can report ridge_vent_length so long as ridge vent is checked in the Supply section of the Options Panel of your roof plane or Build Roof. Otherwise 
• A roof plane can report projected overhang area
• A roof plane can report projected area
• A fixture class of symbol can be set to flush mount on a roof and report the room that it is placed "in" as well as its width, depth, height and custom_fields which can be formatted to report values from macros
• A fixture can have an offset that can work to keep an object in a room when its geometry is outside of the room...such as inside of eave blocks for instance
• A custom_field with a numerical value can have its sums totaled and those sums could be produced from an equation

Now for the bad parts.

• A triangle shaped hip roof will not have a ridge vent to report so it could prove challenging to adjust your equation between 1/150 to 1/300 requirements without some conditional situation.
• A fixture can report area of the room it is placed in, it but that would not be helpful if the room was only partially covered by a roof
• A roof plane does not know what room is below it
• You'd have to get real clever about representing eave vents or soffit vents
• There is no OIP for the Build Roof
• has_ridge_vent doesn't exist as a reporting value from Roof Planes
• there is no easy way to calc attic area with a roof overframe condition

The real challenge is determining what attic space is, whether or not a roof plane satisfies the rule for 1/300 or 1/150 depending on the presence of a ridge vent.

A system you could use is a simple trigger such as the presence of some term in the comments section of the roof
Or you could make the trigger be based on say the prefix of the schedule number where R04 means the roof plane ha a ridge vent and calc from that.
Then the last problem is either using polylines or fixtures to create the nfa value of your vent.

I think my version of a perfect system might be that I have fixtures.
Here is a ridge vent fixture I created that reports nfa as a custom field formatted as a number, derived from its width. Followed by a fixture that represent an eave vent that derives nfa from its widthxheight. Pls roof planes that take projected area minus projected overhang

This does not solve for an overframe condition

[leyi123]

Thank you so much for such great details and pointers! Very helpful! @Renerabbitt I am gonna learn and explore all them, sounds fun!  Thank you again.