Willard3:
That is basically exactly what I had to do. Once they saw the increase in cost (both materials and labor) for all the return ductwork above what they were already expecting, they forced the architects hand to instead to a raised/pop-up ceiling in the area where he wanted to...
Drazen: I agree. That was my concern. Even though I can't find anything in code against it, it seems against good engineering practice as an HVAC engineer.
willard3: I can understand that, but it is still very common practice in many office buildings. The job I am working on has a real budget...
sorry, I think I may have misled you. As you probably know, engineering problems can be a bit tricky to describe simply by a forum post...
I definitely do understand that I need to supply a suitable return air path out of the room - this is definitely normal engineering like you said. My plan...
Thanks for the suggestion and I guess that also answers my question:
So, other than the fact you would have to account for area since the door would be closed at times, you see no code reason the enclosed office HAS to have a dedicated return grille?
The scenario I ran into was that, on the...
I had an issue come up this week that I am curious about. I have always been told something on other jobs by my superiors at work but it is getting questioned on a job I am working on now by the architects and I can't find it explicitly in the code.
The issue is this: In an office environment...
I appreciate the responses.
11241: You are right as far as the code stating something about the outside air, but the only time it mentions OA being greater than the transfer air taken out is in the section on corridors:
"1. Use of a corridor as a source of makeup air for exhaust systems in...
thread403-309881
The older thread was closed, but I have a question regarding transfer air as makeup for toilet exhaust. Someone was stating that it is not allowed by code anymore by saying "transfer of room air to another, i.e use of a room as a return plenum is a code violation."
However...
As others have asked:
What kind of application is this? Is the space occupied? What are the temperature and humidity requirements of the space this unit is serving?
You make it sound like the normal operation is 100% return air and 0% outside air unless the OA temperature falls to a specified...
cry22. While you are technically correct in terms of OVERALL air supplied, I believe MechEng1977 was asking for the minimum code or standard required outside air/makeup air.
Yes, 0.06 CFM/ft2 is not the total amount of conditioned air that may need to be supplied to meet whatever temperature...
PS, a followup to the post I just made. I realized I didn't address IEER.
Essentially you have the same problem "converting" between IEER and EER as you do EER and SEER. They don't measure the same thing Because IEER is a weighted average, you need the EER rating at 4 different load points...
The problem "converting" between EER and SEER is that they don't measure the exact same thing. It's not like measuring a heat loss and converting between BTU/hr and kW.
As you probably know, EER is an efficiency rating measuring cooling in BTU/hr compared to electrical energy input in kW. It...
Stuff like this is always dictated by Code. Code is what is required by law. Often ASHRAE Standards (or at least parts) are adopted into the Code and only then are the ASHRAE standards *required*. (Note required by law is not always the same as good design practice).
I don't know what codes...
Are the AHUs in the penthouse direct ducted to an outside air louver or to a DOA or are there general OA louvers and the AHUs are pulling in "OA" from within the penthouse?
I agree with what others have said. I typically specify my door grilles ~200 fpm.
I know the TRANE ductulator says 200-300 fpm for both grille and door undercut as a rule of thumb but I tend to think 300 is too high (especially for door undercuts).
250 is my upper limit if I am trying to...
