Water Cooling... Just wondering...

The Oper Theater in Hannover (Staatstheater) renovated their dimming system in the 1990s,

and they had a problem that the only place they could put their dimming racks was on stage in the

galleries, which mean no fans could be used. Transtechnik, a german company now owned by

ETC, installed for them a water cooled dimming system. Basically, cold water pipes ran through the

back of the dimming rack, and took the heat away from the dimmers. Very simple process, but

naturally, there had to be tons of electronic/mechanical safeguards that would reroute water at the

moment of any broken seals. All of this pushed the cost of the system, into ten times

what the dimming system normally cost. In 2007, they had their first real maintenance on this system,

which I was able to partake it. As we opened the dimmer rack doors, which were all airtight, the inside

of the racks, looked shiney and new as if they just came out of the factory. Not a drop of dust anywhere.

And in the over decade span of time, there has never been a drop of water out of that system.

Good ol' german engineering. Unfortunately, only a social country as Germany could afford

to put in such a dimming system.

well sounds like etc has a prototype! this could be real cool if you all could develop a product out of it. one off custom stuff usualy cost about ten times more so if it was mass produced it could work.

oh do you have pictures or tech drawings you could post?????

Hi Lane,

sorry but even mass producing such a system, wouldn't cut the costs by more

than 10%, which would make such a system, especially for the North American

market, way unaffordable.

And sorry no photos available. If you are ever in Hannover, maybe we can

arrange a tour of the dimmers on stage.

Hi Lane,

sorry but even mass producing such a system, wouldn't cut the costs by more

than 10%, which would make such a system, especially for the North American

market, way unaffordable.

And sorry no photos available. If you are ever in Hannover, maybe we can

arrange a tour of the dimmers on stage.

that would be cool. has ther been any tests to compare efficency over conventional air cooled dimming racks?

I haven't come across water cooling in a theatrical environment, but it was standard in my previous career as an engineer in the Royal Navy where it was always used to cool equipment racks and display systems.  I believe it was used because the water pipes from a central chilled water plant take up significantly less space than ventilation trunking.  They are also much easier to route around things than vent trunking which essentially needs as fewer bends as possible to avoid obstructing the airflow.

There was a heat exchanger at the bottom of each equipment cabinet/rack/etc fed with chilled water, with extract fans at the top to draw the cool air up and out, where it just went back into the room.  The air supply to/from the room only needed to be for ventilation therefore, not for removing the heat generated within it.  This is slightly a different method to the racks at the Staatstheater which sound as if they were completely sealed racks with no airflow in/out.  As I recall, the heat exchangers & fans we had were thermostatically controlled so the room didn't get too cold when the racks were powered down, indeed the racks also had to have anti-condensation heaters fitted to keep them warm when powered down.  We also had to back flush the exchangers a couple of times a year to clear out any gunk that had accumulated in them, add the usual chemical preservatives you get in domestic central heating systems, and so on.

We also managed to partially flood a computer room when a (flexible) chilled water pipe split one night - ironically when in dry dock, but that's another story...

The upshot, is that it can be done *IF* it offers a significant advantage, but there are significant disadvantages too in terms of additional machinery and maintenance, reduced space in the racks, plus the not so great combination of electricity and water if it all goes wrong - not to mention the ever present consideration of cost.  Unless you can find custom dimmer modules that take a direct water feed though, the actual cooling will still be by (cooled) air so I would have thought you will still need (relatively small) fans in your racks for the airflow, or very big heat exchangers.

If you only want 19" rack mounted dimmers then there are several standard chilled water cooled rack solutions designed for computer data centres - a quick google brings up http://www.americantechsupply.com/watercooledcabinets.htm for example.  I think it'll be a while before we see the launch of the Sensor CW at Plasa though.

Interestingly, the Barco DML-1200 media server/video projector has a water cooling circuit inside, I guess (I don't know) to transfer heat away from the lamp house down to the base where the fans are.  So water cooling is used in theatres after all...

Andy