Summer is Coming...

Off-topic conversations and chit-chat.

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I love the summer, but I'm not a fan of working in a humid, 85+ degree lab all day long. Besides, when I'm running 8270 SVOCs with DCM as a solvent, it seems to work best if I can inject onto a relatively cool column. It takes forever to cool the GC ovens down to 35c when the room is almost 30c.

Anyone else feel my pain? How hot (or cold) does your lab get? Am I the only one who has to melt their glacial acetic acid in the winter? Ever find a way to solve the problem without spending a ton of money?

I'm told that the reason for this is that we're legally required to replace the air we lose though the fume hoods with air from outside the building, rather than drawing some of it in from the rest of the building (which is fairly temperate).

I'm also curious about how much heat the GCs put out when they are idle. I'm seeing figures in the 8000 btu/hr range but I think that's when they are cycling from hot to cold. Most of our 5 units are idle most of the time. On the other hand, we have an ICP constantly running, with 6000 btu/hr being vented into the room by its chiller. Whether that's significant or not depends, I guess, on how close to peak heat the other instruments are emitting when the inlets/outlets/pumps/detectors are hot but ovens aren't doing anything.
We have dealt with this the last few years. A 15 year old 75 ton HVAC unit is beginning to show it's age. When our building was new you could hang meat in here year round, we even had people wearing hooded sweatshirts in the middle of summer. A few years ago it went completely out and for a couple days it was 95F in the lab with about 90% humidity, the floors were actually covered with water.

After some work things are running better now :)

You do have to replace the air that the hoods draw out, otherwise you would either pull a vacuum on the building or there will be no flow through the hoods. That air will either need to come through the HVAC, and be cooled or heated to maintain the building temperature or it will be pulled in through any opening available and you are then at the mercy of whatever the outside air temperature and humidity is.

We vent our GC ovens outside the building to lower the load on the HVAC, plus using powered exhaust vents helps pull in the cooler lab air for faster oven cycling, so you gain twice with that. Lab temperature control is definitely not cheap, if you are running anything more than one or two instruments, and the more consistent you can hold the temperature, the better the instruments will perform, calibrations do not like large temperature swings.
The past is there to guide us into the future, not to dwell in.
Our GC lab is a small room with a 7 total GCs in it, although the two GC-MSs are the only ones that stay on all the time.

There are four SRI GCs(FID/TCD) that primarily get used for teaching. When they're in use, the room gets awfully toasty, but I suspect it's more from ~15 people being in the tiny room than the GCs themselves. For the vast majority of teaching experiments, they are used as isothermal instruments, which means that they're not dumping out a bunch of heat from the oven with every run-they're insulated enough that the heating elements rarely turn on to hold their set point(110-130º depending on the specific instrument and the column installed-I tweak each individual instrument to keep the analysis time under 5 minutes, and preferably as short as possible with adequate resolution, to maximize throughput and the ovens are insulated well enough that the heating elements don't kick on that often to keep the set temperature).

Our GC lab does not have fume hoods, but there are hoods in the adjoining labs-the doors to those rooms are usually open. All the make-up air comes from the HVAC system and is conditioned to what it thinks of as the room temperature. Since no one seems to understand how the system in our building actually works(and it gets messed up to no end because several labs have removed hoods and then had their own HVAC installed-there's a computer and 3 NMR labs on the same "pod" as the GC lab that have all done that) we're often ~60ºF in the summer and ~80ºF in the winter. Of course, other rooms have their own pecularities and are either always hot or always cold. Our HVAC system is designed to run hot and chilled water year round and use those to regulate the temperature, and the summer cold temperatures often come in when the hot water supply is either down for maintenance(we have a small boiler in our building, and it seems as though sometimes they shut it down and forget to switch us over to hot water from the campus plant across the street) or for whatever reason gets shut off in one particular wing/room/etc.

In any case, the only time I seem to run into appreciable heating from the GCs themselves is with one particular method that one graduate student runs. It starts at 55ºC, ramps to 300º, and holds there for 30 minutes. Since his method takes ~1 hour per sample, he often runs both the 5890/5971 and 7820/5975 at the same time. Those can heat the room up a whole lot.
The lab where I worked was completed in 1975; there were always temperature issues in each aisle in the lab. There was sufficient data to show that the thermostats in each aisle were actually "for show".

So when the company moved into a newly-built lab about 2008, we expected that with modern computer controlled systems that things would be better. No. And we were ordered not to touch any thermostats there. Our department was always cooler than most, so we just agreed to keep quiet about that, and agreed that the folks would wear lab coats or sweaters if cold. So I think overall the modern system was worse, and the office side facing the sun had huge windows and got real hot every afternoon. Electricity costs were killing them.

One reason for the downsizing there that caught me was that the building's fixed costs and operational costs were too high...

So why was a new building needed in 2008?? A former CEO sold our property, and before land values went way up....
Oh, thermostats! There is no hope! If you don't have air-con and cooling, instrument labs get so hot the instruments stop working. If you do, your friendly engineer installing a ToF says it can't be near a window, nor can it be near the air-con, because both will mess up its stability. So everything in the lab needs to be in the ten square feet of bench-space that's up a corner away from the window and not next to the air-con. You get it set up there, and then the H&S chap complains it's too close to the door.

In my hopefully-not-yet-over career, I've come across a room that was freezing because someone put a -20 freezer up against the thermostat (the heat-exchanger grill on the back of the freezer touching the thermostat). An engineer who modified our fridge to make it compatible with flammable solvents by moving the thermostat to the outside (fridge became an inefficient freezer; he was a good engineer at many other things, that wasn't his brightest moment, but he did lots of really good work elsewhere for us). And, my favourite, two senior staff in tiny offices, one who hated heat and was stuck in a 35-degrees sauna, the other who hated cold and was down to 12 degrees in the winter. 'Hot' set his thermostat as cold as it would go. 'Cold' turned his up to the maximum. It turned out the thermostats were in the wrong rooms...
lmh wrote:
And, my favourite, two senior staff in tiny offices, one who hated heat and was stuck in a 35-degrees sauna, the other who hated cold and was down to 12 degrees in the winter. 'Hot' set his thermostat as cold as it would go. 'Cold' turned his up to the maximum. It turned out the thermostats were in the wrong rooms...


Reminds me of my brother when he got 2 bark shock collars for his 2 dogs; dog 1 was barking and he kept turning up the voltage but dog 1 continued barking, and 30 feet away dog 2 was going into convulsions !!!

Like in my home - for which I had a pre-purchase inspection - the hot and cold outlets for the washing machine were reversed; easy fix was just to swap the knobs so color code/label would be correct, and swap the hoses.

My first home - a townhouse purchased new - had the 240 VAC kitchen range wired up as 120 VAC.
We had the thermostats in the wrong rooms problem in our old building too, and it had a floor to ceiling window where the old Thermo 61E ICP was, and once the sun would come through the window the calibration would be blown totally out of the water. Luckily the window problem was solved with a set of blinds.

In that same building we had a room for volatiles, that had its own 3 ton AC unit, the type where there is just a blower mounted on the wall and the compressor sits outside. No heat was needed in that room because if the AC died even when it was 20F outside, the room would be 90F inside in a matter of minutes. Well with so much trouble heating and cooling the rest of the building we had a contractor come in and redo all the heating and cooling except for that room, I even told them not to connect us to any heating or air ducts. As they were tearing out the old systems(had 4 different residential units connected to different rooms) we had a heating duct from three other units connected to old outlets in the volatiles room. So no wonder the little 3 ton was working so hard, in winter we had three other heating units sending hot air at us :)
The past is there to guide us into the future, not to dwell in.
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