Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.

Air Turns


Air Turns | 21 July, 2001

In the past, we have spoken [typed?] about controlling the temperature and humidity of our plants. And it's probably good to do that from solder process control, ESD danger reduction, and human factors stand-points.

We are looking to lower our energy costs. What are your requirements for turn-over of air within your plant? We have been rooting through the US OSHA stuff and really can't find anything. Someone's thinking is: If turns are too low, CO2 reaches a level where it is harmful for people.

[See. This one of the pains in the arm of a collaberative work environment. In the past, we'd just crank down the the pump on the a/c 'til they started dropping. Then, we'd let-off abit n everyone would be happy, happy.]

Hey Ashok, where are you? You must have done this drill when installing yer new a/c.

reply »


Air Turns | 23 July, 2001

A minimal ventilation rate is 0.05 cfm per square foot, as recommended by the 1998 International Mechanical Code. However, this may not take into account other potential building contaminants from such sources as propane forklifts, which require a minimum ventilation rate of 5,000 cfm per vehicle, according to the American Conference of Governmental Industrial Hygienists.

reply »



Air Turns | 25 July, 2001

You got it .05 cfm per sqr ft. But that�s the easy part, how are you calculating exchange rate? that�s the tough part. If you want to get it right and keep heating/ac costs down. What I mean is, if you don�t take into account the infiltration and air being exhausted you could easily exceed the exchange rate, which would mean you are heating or cooling to much. There are so many variables to add to the equation, but it can be figured correctly with a little thought.

reply »


Air Turns | 25 July, 2001

We had planned to touch-off a "smoke bomb" after hours and measure its progess. {Obviously, we are not BIG on thinking.]

reply »

Michael Parker


Air Turns | 26 July, 2001

Why not a stink bomb during regular work hours? (If you can get any methyl mercapton, that stuff is very odorific. Smells like baby's barf. A little dab'll do ya!) That way you could gage the complaint ratio as time goes by. Could save you much elbow grease from pushing that slide rule back and forth and the occasional noggin' scratchin'!

reply »

Reflow Oven

Metcal soldering rework