2D HVAC

[SH_Canada]

I've had a couple inquires the last few weeks from commercial people leasing a new space and wanting to change a few walls. The city is requiring HVAC plans, 2D only. I've now done a couple of these simply by drawing CAD lines. But I soon realized this is a bit of a slow boat to China, and granted I'm not a huge fan of just drawing lines either, so the tediousness of it all is wearing thin.

 

Chief has a video on spiral ducting, but that is basically for the 3D viewing. And there is a CA Q&A, which basically says yes CA does HVAC drawings, use CA CAD tools. Not much else in the forums, or at least not in the first 7 pages in a search for "HVAC"

 

So a question for those that might be doing this more often than I. Are you using a bunch of prebuilt or predownloaded CADs and simply put them all together? i.e. 4" 90s, 4" 45s, 6" 45s, 6" 90s, 12",16" rectangular, take offs, reducers, etc.

 

I ended up with this today below

 

but I started to get lazy and omit the takeoffs, and was not sure what to do for the flexible pipe representation.

 

Any ideas would be welcome...and hopefully I hear from someone who does these fairly often.

 

The curves were a PIA especially the one which goes to a wider duct. The curves were basically a guess as to what the radius of curvature is and I did not spend the time to measure or go to the local HD to measure. It's one of those things where I'm not sure people care, but it would be nice to get it right.

 

When I looked at a sample drawing, it looks like whomever did it just put a bunch of premade blocks together, as you can see the 90 deg offset lines where the pieces connect, like I have to the left of the reception, but to the right of the utility I actually spent the time to draw two lines and two curves (instead of the polyline rectangle)

 

thanks

 

 

 

[GeneDavis]

Are you well-trained in HVAC design?  Are you being paid by the hour to do this?

 

Chief CAD will work OK to do this.  If you have some 2D images or drawings of fittings in plan view, you can use to draw Chief CAD atop, then copy and place wherever needed.

[SH_Canada]

2 hours ago, GeneDavis said:

Are you well-trained in HVAC design?  Are you being paid by the hour to do this?

I dont do design, I do as builts. I sent them off to an HVAC engineer if they need something designed, and then they do their own drawing. It seems there is bit of a market for minor interior commercial renovations in this city, and drafting the HVAC is part of the City requirements. Apparently, in talking to an HVAC engineer, there is a bit of a grey zone in small square footage commercial, where there is not a requirement for professional design. Which explains why the City wants it, but does not require engineer stamp. ASHRAE is the standard, which I believe started in the US. Interesting price difference, $4k for the engineer or $500 for the draftsman, and with the engineer, the owner risks having to do more stuff.(I can already hear what people are saying "maybe more is required". But from the owner point of view, the only thing that changed from last week are 3 walls, if people were really not "safe" yesterday, then the govt should be mandating on existing buildings)

 

Interesting bit of regulation limbo. 

 

I charge an add on, yes by the hour to go inspect, measure and draw ductwork, I just dont like to do it with polylines.

 

sounds like I need to go find some premade 2D CAD blocks.