Richard_Morrison

Crawlspace Vents?

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Has anyone found a good strategy for placing crawlspace vents? I'm talking about the 5" x 14" type that sits just above the mudsill, usually within the floor joist space. Put them on the first floor, they screw up the floor plan. Put them on the foundation level, they don't display properly in 3D.  So far, the best option seems to be to make the first floor a pony wall, with upper & lower the same wall type, and put the vent in the lower portion. But maybe I'm missing something.

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I been using regular window (stripped) and resized to block size 16x8. I hope it helps.

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I been using regular window (stripped) and resized to block size 16x8. I hope it helps.

 

Wasn't really the question, but you should be aware that there are already foundation vents like this in the library. And if they are designated as vents, rather than windows, you can easily exclude them from window schedules, and also create a separate vent schedule. Hope that helps. ;-)

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Has anyone found a good strategy for placing crawlspace vents? I'm talking about the 5" x 14" type that sits just above the mudsill, usually within the floor joist space. Put them on the first floor, they screw up the floor plan. Put them on the foundation level, they don't display properly in 3D.  So far, the best option seems to be to make the first floor a pony wall, with upper & lower the same wall type, and put the vent in the lower portion. But maybe I'm missing something.

You and me brother are sometimes as dumb as rocks.   I have been struggling with this for 10 years.  I was thinking about it and I have now figured out how to do it.  I will post a vid soon.  Thank you Thank you Thank you for the question.  It is now solved for me.

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Thank you Richard, it does help ! I never even looked for them in the library since I don't do or use schedules at all, so windows always worked fine for me. 

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Do you guys install vents into a rim joist on remodeling jobs only? Or that is how you design crawl space ventilation for new construction also?

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Do you guys install vents into a rim joist on remodeling jobs only? Or that is how you design crawl space ventilation for new construction also?

.....  vents are typically between floor joist bays.  Whether new or remodeling,  the vents are typically between floor joist bays.

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Here we always put them in the block, because the crawl space is insulated. 

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Watched the video 3 times and was wondering how you define the windows as 'vents'? The best I can do is define them as Louvered.

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Here we always put them in the block, because the crawl space is insulated. 

That makes a lot of sense......  many of the homes I deal with are existing and back in the day there was no insulation in the crawl space. We are in SOCAL,  heck, often times we deal with homes that have jalousie window....  as in not dual glazed and definitely not sealed.  

 

Good comment Greg.

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Watched the video 3 times and was wondering how you define the windows as 'vents'? The best I can do is define them as Louvered.

Dog gone you Larry,  I thought I had it figured out.....  you are correct,  hmmmmmm.......  Richard's vent from library does not work at floor joist bay,  not good,  but Richards vent from library gives the area total of vents......  I must work on this some more.....

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Okay Larry,  I have it figured out.......  two schedules,  one for windows and one for LOUVERS.  We will never use  louver WINDOW again  but we will always us louver VENTS,  so we can use the louver designation to give us an up to date and accurate total of louvered vent area.

 

You are correct,  I cannot use VENTS for my crawl space ventilation schedule,  but I can use LOUVERS.....  I think this should work for most applications.

 

The idea of having an additional designation for WINDOW SPECIFICATION<GENERAL<VENT is something I should suggest in suggestions.

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dshall,

I originally started at the same place as you did, but when I moved the vent up into the joist space, the rim joist and the stucco made the vent not look good. Your video reminded me that we can use a negative inset to get the window or vent to move out. So, good job and thanks!

 

Take a look again at the vents in the library. They are made from windows but are a special window type: VENT. I'm not sure why that choice is not in the drop-down Window DBX, but it isn't. Seems like you can only get there by using the library symbol, or creating your own. But VENT is a separate type of window that can be scheduled by itself, and has the area available for scheduling. Unfortunately, there is no Net Free Area available, which would be awesome, but maybe in the future.

 

BTW, gable vents from the library can be scheduled similarly to foundation vents.

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Nice one Scott, I was using your vent symbol until now, automatic S.F. is nice, just change the window sched. name to a "vent Schedule" helps a lot.

Maybe we could take a gable vent from the lib and change it somehow

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dshall,

I originally started at the same place as you did, but when I moved the vent up into the joist space, the rim joist and the stucco made the vent not look good. Your video reminded me that we can use a negative inset to get the window or vent to move out. So, good job and thanks!

 

Take a look again at the vents in the library. They are made from windows but are a special window type: VENT. I'm not sure why that choice is not in the drop-down Window DBX, but it isn't. Seems like you can only get there by using the library symbol, or creating your own. But VENT is a separate type of window that can be scheduled by itself, and has the area available for scheduling. Unfortunately, there is no Net Free Area available, which would be awesome, but maybe in the future.

 

BTW, gable vents from the library can be scheduled similarly to foundation vents.

Got it,  I could not get SYMBOL VENTS from library to look good,  hence the request for the SPECIAL WINDOW TYPE:  vent.  

 

Nuts,  you know what I am talking about,  I think we are on the same page.

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Maybe I wasn't clear. The Library vents (both foundation and gable) are NOT dumb symbols, really. They are actual WINDOWS with the "Vent" type already defined, which is not available elsewhere. They also have their own label type, which is nice.

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Maybe I wasn't clear. The Library vents (both foundation and gable) are NOT dumb symbols, really. They are actual WINDOWS with the "Vent" type already defined, which is not available elsewhere. They also have their own label type, which is nice.

Yes,  I get that,  but when I used them in my  plan,  the 3D look was not good.  If you disagree and you think they look good,  would you mind posting a small plan so I can see how they look.  

 

If you watched the video,  maybe you noticed the issue I was talking about.  

 

Here is a question.......  does the symbol out of the library look better than the window/louver that I was working with?

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Super helpful Richard, Scott. I couldn't get the vent to work in 3D up on the first floor framing. Fine on the foundation but not so much on the stucco finish above.

 

Just place the vent in the first floor and position in elevation and it works fine DOH. I was trying to drag it up from the foundation like original vid. Too easy, and it shows as a vent in the schedule.

 

http://www.screencast.com/t/20mhslgrfuBk

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Here is a question.......  does the symbol out of the library look better than the window/louver that I was working with?

 

It looks identical, IF you go the frame and adjust the inset. (Need to uncheck "Fit Frame to Wall.") However, it will schedule with a VT prefix and the schedule can be set to show only vents. So you can have part basement, part crawlspace, with windows and vents labeled differently.

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..... IF you go the frame and adjust the inset. (Need to uncheck "Fit Frame to Wall.")......

 

Why am I so stupid?  If I adjust the inset I see no difference.  I suppose that is why I requested a small plan so I  could study it.  If it is too much trouble to post a small plan,  no worries......    

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If I adjust the inset I see no difference.

Adjusting vent offset shows no movement in 3D, only in plan view is what I discovered.

 

I also discovered the vent area is not correct nor can you use the schedule area for the air movement calc needed in vent calcs.

 

Where is that area of a 14 x 4 vent coming from? Uh...maybe try 1'4" x 4"? 

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Larry,

You are right about the 3D views. Not sure why this seemed to work before.

Here is a picture of the same vent symbol, on the left placed into the foundation and dragged up, on the right placed into a pony wall on the first level. (Top & bottom of pony wall are same wall type.) Creating a window gives you some more flexibility with placement and 3D look, but less flexibility with the schedule. I guess you take your choice.

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Is it that easy?

 

 

No, it's not that easy, because unless you put them in the bottom section of a pony wall so you can display the upper section in plan, they will show up on the floor plan and be very confusing. Not sure yet where the sq. ft. is coming from, but you are right that it does seem wrong. Certainly for a louver vent with reduced NFA.

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