How do architects guestimate the size of chases and bulkheads for ductwork passage…before the ductwork is sized? - Jinx
IANAA but I have built my fair share of houses and remodeled more than that. Ducts come in standard sizes such as 6x6. 10x10, 14x12, 6,8,&10" radius, etc. In most cases they are designed to fit between standard 16"o.c. stud openings. Ductwork can be custom made but this is prohibitively expensive and is usually only used for odd transitions and to navigate existing conditions found in remodeling
Also one of the jobs of an engineer and/or architect is to calculate the duct air capacity and determine exactly what will be needed for a house depending on the total square footage of the space, the HVAC system, size of individual rooms, length of runs of ductwork, number of turns and their angle, need for internal duct insulation, location of mechanicals, and a bunch of other factors which are escaping me at the moment. So I would respectufully submit that they do not “guesstimate”, they specify.
In many cases, they don’t. I’ve seen lots of projects where the architects intended the ductwork to run through a chase that was so small, the velocities required could go supersonic. Good architects can leave adequate space based on previous experience and rough calculations. Bad architects don’t bother and have to modify the plans when the engineers call BS.
Short answer is, we don’t. Well, certainly more specifically, I don’t.
In a job large enough to require major ducting for services a Building Services Engineer / M&E Engineer will be employed and he/she can do the guestimate before any final sizes are confirmed. I could do it if necessary, but it is not generally in my remit and thus there is no reason for me to take responsibility for such a calculation. Especailly when others can do it better, quicker and, ultimately, take full responsiblity for any miscalculations.