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Basement Outdoor Air Ventilation 2

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Bigwiggz

Mechanical
Oct 4, 2012
21
Hi Guys,

I have a ventilation question, I have a project with a basement renovation. Below are some general info about the Job.

Location: Raleigh, North Carolina (Somewhat Humid Summers)
Basement Size: 41' by 73'
Project Type: Place of Worship
Room loads are handled by mini split units in various zones for individual control.
There is only 10" of space between the first floor trusses and the suspended ceiling to run duct work.
I am limited to branch runs of 6" duct and possibly an 8" main trunk.
There are five rooms, Main Auditorium, 2 meeting rooms, a Lobby, Women's Restroom and a Men's Restroom.

The basement currently has NO fresh air. Post-renovation of course will require ventilation.

I ran the numbers on using an air ionizer for the fresh air intake and I have a manufacturer's calcsheet that lowers the fresh air for the basement to 3.5 CFM per person using the ASHRAE IAQ method. However, I still need 600 CFM of fresh air to the basement rooms and the restrooms. Since it is a basement, I was thinking about using two Aprilaire Dehumidifiers 1770A and have it pull in outside air, dehumidify the air and provide fresh air in the space.

1) Is this the best way to provide fresh ventilation/dehumidified air to the basement to meet ASHRAE Requirements (There are already mini-splits in each of the rooms for occupant comfort)?

2) What would you put to solve the fresh air ventilation problem?


I see a slight over pressurization of the room because the room too.

Thanks for your help!
 
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your idea sounds good. as long as the CFM's are correct when checked at loading. the over pressure should not be a problem. have you run the numbers with bathroom exhaust added in?
 
You will have to heat the OA in winter as well as cool/dehumidify in the summer.
 
That would be additional load to your split units, unless you cool it before you supply to basement.
 
Thanks,
That would be additional load to your split units, unless you cool it before you supply to basement.
I will take that into account when sizing the mini-splits.

have you run the numbers with bathroom exhaust added in?
Yes, the numbers above include the bathroom exhaust.


Thanks for your help!
 
Does anybody know where I find a firm that can help with MEP design very fast? I've got only a week. Need to have it done till May 2nd?
Thanks for help!
 
Look up mechanical engineering firms or try HVAC contractors in your area.
 
Thanks! I was trying to find but nobody can do it within a week.
Do you know any exact firm who can?
Will appreciate if already tryied and it was done fast with a high quality.
 
Fast and high quality are mutually exclusive in Engineering.

 
As a last resort, try a local HVAC institute or a ME department of a local university or college including community type.
I live in MA, so I can not help you, otherwise.
 
Try Elmech. I used their services already twice. And I'm satisfied. They've done MEP designs within 4 days! They are in Maryland but did it for me anyway. I'm in NY. Here is the phone number I contacted 4105305364.
Think they'll help you.
 
Thanks a lot! Already gave them a call. They will do that. Hope they are good.
Take care!
 
Hey Kewin! Thanks again! They've done excellent job. All in time and with super quality.
 
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