Film-Tech Forum ARCHIVE: Glycol Vaporizer

This is topic Glycol Vaporizer in forum Film-Yak at Film-Tech Forum ARCHIVE.

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Posted by Mark Lensenmayer (Member # 134) on 04-20-2010, 03:25 PM:

In doing some research on local theatres, I came across an ad for the Old Trail Theatre opening in 1948 that mentions

quote:
Glycol Vaporizer Unit Sterilizes the Air--Killing Instantly Cold and Flu Germs and All Airborne Bacteria

Has anyone ever come across such a thing? I guess this made your theatre "state-of-the-art" in 1948!

This ad also mentions the new slideback chairs, roomy seat spacing, finest sight lines, perfect accoustics, fireproof construction throughout and no-draft ventilation.

Posted by Adam Fraser (Member # 1074) on 04-22-2010, 09:15 AM:

The original newspaper article from the opening of my theatre in 1941 lists some kind of ammonia air sterilizer. I don't know anything about it though and there are no remnants of the system left.

My wild guess was that there was some kind of sprayer near the heat exchanger to remove suspended particles from the air. Honestly, I have no idea though and there is no mention of the system in the original mechanical blue prints.

I assume it was some kind of '40's fad that customers demanded at the time. Similar to businesses advertising "green" technology today.

Posted by Randy Stankey (Member # 64) on 04-22-2010, 09:39 AM:

Didn't most air conditioned theaters of that period use giant swamp coolers whereby air was passed through giant water-saturated pads? The Warner theater in our town has such contraptions in the basement. They are large walk-in contraptions.

As such, aren't they susceptible to growing bacteria and things?

Therefore, doesn't it follow that companies would have to take measures to disinfect their air conditioning systems? Today we worry about things like Legionaire's disease which was vectored through contaminated air conditioning systems. Wasn't it?

So, it's my guess that a glycol vaporizer was some kind of contraption connected to the swamp coolers to keep them from becoming contaminated and, thereby keeping the air in the theater clean and safe.

Posted by Adam Fraser (Member # 1074) on 04-22-2010, 09:44 AM:

We still have a swamp cooler, but it works similar to a radiator in a car. Ground water is passed through a 10' wide radiator and air is passed through it. We have a condensation pump that reduces the humidity in the heat exchanger room to prevent bacterial and fungal growth.

That could be the case though.

Posted by Bill Enos (Member # 440) on 04-22-2010, 09:54 PM:

Swamp coolers only work well where the humidity is low. In the southeastern U.S. They are useless

Posted by Jeremy Weigel (Member # 4208) on 04-22-2010, 11:53 PM:

quote: Bill Enos
Swamp coolers only work well where the humidity is low. In the southeastern U.S. They are useless

Then why are they called "swamp" coolers? [Razz]

Posted by Kenneth Wuepper (Member # 1174) on 04-23-2010, 07:25 AM:

Adam,

Most of the theatres in Saginaw were cooled by this early form of Geo-Thermal cooling. I believe that it was invented by a Saginaw heating engineer. The first requirement is a deep well with lots of water. Deep ground water is about 50 degrees all year around.

There were two forms of the system, open circuit and closed circuit. The open circuit took 50 degree water from a well deep in the ground and released the water above ground. The closed circuit form used two wells, one deep one for supplying cold water and a shallower one for returning the water below the ground. The closed circuit one has less effect on the water table beneath the surface. All currently operating systems must be of this type.

These units are very effective in cooling the air but lack the ability to remove humidity. An extra refrigerated unit can be added to the system to remove humidity and make the room feel cooler. Low humidity aids the human body in evaporating perspiration and cools the body.

"Swamp Coolers" are an open system and use evaporation from a wick to lower the temperature of the air. Water for these coolers is usually from the drinking water supply. Since they add humidity to the surrounding air in the process, these work only where the natural humidity is very low. The added water vapor makes the human body's evaporation less effective.

Hope this is helpful.

KEN

Posted by Robert Minichino (Member # 3495) on 04-23-2010, 11:53 AM:

Before refrigeration was common, desiccant dehumidifiers were common. These used some sort of desiccant medium (today it would be silica gel, not sure what it would have been in the early 1900s) to absorb the moisture from the recirculating air stream, then that material would have been taken out of the building air stream and dried with heated air, then cooled back down to room temperature and reinserted into the air stream.

Based on the naming of some electrical circuits on early versions of the blueprints, I think the original plan for our theatre was to have a desiccant-type dehumidifier in tandem with an evaporative cooler, but this was changed to a CO2 type refrigeration system before the building was constructed in 1929.

Posted by Kenneth Wuepper (Member # 1174) on 04-23-2010, 04:49 PM:

Early refrigeration used Ammonia, Methyl Chloride or Sulfur Dioxide as the gas to be liquefied under pressure and then returned to a gas. This process generates heat on the "condenser side" while absorbing heat in the "evaporator side".

While the geo-thermal method used 25 HP for the well pump and 25HP for the air circulating fan, the refrigerant system we have now uses 120HP for the compressor and 25HP for the fan. Of course the humidity is reduced as the evaporator core is capable of freezing the condensed water if there is insufficient air flow over fins. The refrigerant is the new environmentally preferred one.

KEN

Posted by Jack Theakston (Member # 4484) on 04-23-2010, 04:54 PM:

Propylene Glycol vaporizers were favored in places like schools and public places (such as bus stations) because Glycol is harmless to humans, but does sterilize germs.

I assume they've fallen out of favor because people are paranoid about anything short of oxygen, but it's the main component in fog machines today.

Posted by Randy Stankey (Member # 64) on 04-23-2010, 05:29 PM:

Interesting thought!

We use glycol based fog juice in our hazer/foggers on the stage. People are constantly fussing about the "smoke" and saying how bad they think it is.

Now I can tell people that it's actually GOOD for them! [Wink]

Posted by Paul Mayer (Member # 355) on 04-23-2010, 05:51 PM:

We used glycol or dry-powder smoke generators for years on 'Vegas stages. And we used to get the same complaints - more from the powder smoke machines (and pyro smoke) than from the glycol machines I think.

On stages where there was lots of pyro or other smoke, many stagehands wore masks. The powder stuff was very acrid and really irritated the throat.

My favorite fog was from dry ice - it hung low to the deck and looked very pretty.

And of course glycol is still used for de-icing and anti-icing on aircraft. At least there you don't have to breathe the stuff.