Neil_K

Can someone confirm something for me on code vs. ethics? Long story short (and spare the unnecessary details) my new employer had a new HVAC unit installed shortly before I came aboard. Two things I saw were wrong - one is the air return duct was not sealed against the unit (about a 1" gap on one side!). The other is that the drain pan that it sits in has about 6" of drain pipe that is capped. Is it allowable to *not* drain it? If/when the unit overflows, it will come right in our ceiling.

An "inspector" came out and said it was okay, but I speculate that they just checked the gas line. The unit was a replacement and apparently the old one was not in a location within code because it was placed between a truss and the firewall between offices. There appears to be a drain line went from that location to somewhere.

Thanks for the comments.

Neil

mdshunk

I'm not sure what the inspector was checking on his trip out, or what particular code text your area uses for mechanical installations, but this MIGHT BE a violation under most codes that I'm famaliar with. Most of the country is on the International Mechanical Code now, so that's what I'll reference.

There's a little more than half a page of code text in the IMC regarding condensate drain pan piping, piping material, condensate discharge areas and the like. §1411.3 is the general section on condensate disposal.

In short, the regular condensate drain on the coil and the auxillary drain pan must have seperate drain lines. They are not permitted to tee together. The auxillary drain line must be run to the disposal point UNLESS there is an overflow detection device (normally a tiny float switch) installed on the drain pan. This is float switch is commonly installed nowadays, regardless of whether the overflow pan is piped or not. The overflow switch normally breaks the "Y" circuit.

If your overflow pan lacks the overflow switch, then you need to either pipe the overflow out, or install the overflow switch.

Neil_K

Thanks, Mdshunk. I just took a look and there is a switch on the side of the pan. There's also a separate pipe from the unit that goes out somewhere.

I still question the guy's ability the way that duct is halfway off, been sucking nice, dusty, insulation-filled air into our office. Maybe, we'll stop sneezing so darn much after its fixed. I'd do it myself, but he won't let me . I have multiple duct tape colors (orange, blue or gray) for all occasions!

mdshunk

I know you were just being silly, but there are requirements on this too. I assume that this was ductboard. The tape used to seal/join the ductboard must be marked with "UL 181A-P", which is a special designation for tape designed for this purpose. Your household duct tape will not suit. Code §1601.3.1 also dictates that the duct connection to the air distribution equipment be a mechanical connection. You can't just "tape" the duct to the air handler.

Neil_K

That, I did not know. Its actually not ductboard though (assuming duct board is the square ducting that the flex stuff comes out of?). The return duct actually has a flange that apparently has two-sided tape that sticks to the side of the unit. The two sided tape is not strong enough to hold and keeps falling off. Fortunately, its close enough to the floor that it doesn't fall completely away.

I'll be sure to ask the guy that shows up to fix it.

Are there any repercussions of sucking attic air through the unit, other than attic dust in the office (and good circulation).

Thanks.

mdshunk

Probably no reprocussions that changing the filter wouldn't correct. This return duct with the flanges and the double stick crap should have had Tek screws ran through the flange at intervals the whole way around. Was this installed by some kid for an Eagle Scout project?

Neil_K

He apparently subbed it out, since he usually only does repairs. I guess if he hires lousy subs, it will keep him busy with upkeep...