Originally posted by joe shmo
Wow, thank you, and please thank your resident HVAC engineer for me. I greatly appreciate it, and I will certainly look into purchasing the manuals!
What state do you live in, if I might ask? There might be local ordinances that supersede some of the stuff in the manuals, not sure but that might be the case. There certainly is some of that going on in electrical codes.
Looks to me like the best part of the advice from Pat is to use variable dampers on each outlet, allowing you to adjust the flows and balance the whole deal a lot easier.
Do you have proper instruments that measure air flow? My guy here has air flow meters and uses laser temperature probes to measure the duct outlet temperatures to see if the heating and air conditioning systems are working correctly. I think he said they generally like to see something like 50 or 51 degrees F coming out of the vents for air conditioning and 80ish for heating.
In case you are light on instrumentation, here is a link (just at random) that sells various kinds of airflow meters:
You can see you can get some for under 200 bucks and some more serious ones in the 4000 dollar area. For you I would suspect the cheapo one would work just fine.
As it turns out, here at my company, we had extreme issues with just that area, one of my semiconductor manufacturing machines, called a Sputtering tool, was installed in what used to be a loading dock! Can you imagine a worse place for a machine that has strict temperature requirements? If it got lower than 60 degrees F, some dam oring in the vacuum seal went and the vacuum inside went from 1 E-7 range, a very nice number and sometimes even lower, like 6E-8 range! But get the machine to 60 and all of a sudden its 2 or 3 orders of magnitude higher, which sucked because it didn't suck
So I spent a lot of time troubleshooting with helium leak checkers to find the bad oring and maybe found it but it has turned to summer here in the east and won't be seeing 50's for months now so don't know if I nailed it or not till then.
At the other end of the heat spectrum, my computer craps out if it get up to 80 degrees F internally so I had to add a personal chiller to that dam computer would you believe, I adjust the thing closer or farther from the comp to keep it at around 70 degrees where it is happy.
So we had a lot of ductwork to do, adding heating and cooling elements which was no easy trick because we have only X amount of heating and cooling for our labs and Pat had his hands full borrowing from peter to pay paul!
I think we finally convinced our new (thankfully) CEO that we need some serious attention to the heating and cooling system.
They know that now, we have rubbed that in the face of management, especially after the sputtering machine debacle!
Now they KNOW we are going to need a LOT more cooling on the roof since we are expanding our cleanroom to hold a lot more machines like that that really add to the heat load of the whole building.
Another hitch in our plans. which I discussed yesterday:
Our outside power transformer taking in the 13,000 volt line to 480 and then to 240/208/120 etc, is only rated at one quarter megawatt.
We are pushing the hell out of that limit already and for instance, we have a huge air compressor that costs the company 3000 bucks a month just for electricity and so we installed 'baby' air compressors for just three machines in R&D and some production to handle just those so we can shut down the big guy at night saving quite a bit of money.
Those baby compressors just can't handle it, not reliable enough. They are less than 200 bucks each but we have gone through four of the dam things, and now I am pushing for a larger one, like you see at gas stations, much more reliable but of course closing in on a thousand bucks a pop.
The owner of our company didn't mind that but the power limit is crunching us and we have to find 208 3 phase and something like 25 amps to run it and that pushes us ever closer to our 1/4 megawatt limit AND it is going to cost another thou for the electricians to wire it up properly.
So now it is a 2000 dollar project, where we had been spending 200.
But now we have already spend 800 on those stupid baby compressors that keep dying, so I think management can see the light at the end of THAT particular tunnel.
The problem for us with that 1/4 meg limit is the power company refuses to give us a larger transformer, the bastids!
So I told that to the owner of our company and told him it might take upper management words to THEIR upper management to get us a bigger transformer.
The expansion we are contemplating will run us out of power in 6 months the way it is now so it is a serious issue!