We have just bought and installed an Omtech 100W CO2 laser with CW5000 chiller. It is in our unheated workshop, at the back of our retail shop in Wales. When it arrived and we did our first tests it was in the middle of a long dry heatwave. Humidity was 45%. Since then we have had a lot of rain and our humidity in the workshop has been over the 70% stated as the maximum operational humidity in the OMTECH manual. As I understand it the humidity is important to avoid condensation on the tube - but surely the dew point is the figure you need for this?? What I really want to know is how safe it would be to run the laser in higher humidity (75-80%) providing I set the chiller temp higher than the dew point?? For instance, with a humidity of 80%, and an ambient temperature of 22 C, the dew point is 18 C. If I set the chiller temp to 20C this should avoid condensation on the tube?? Are there any other things I should take into account regarding the humidity? I have never seen condensation or rust on any of the metal tools etc in the workshop. Wales is very wet and we can’t sensibly environmentally control our workshop as it adjoins the retail shop which has the door open to allow customers in (although we might be able to add some form of heating in the workshop).
With the temperature set you specify, I can’t really see a problem with condensation. Of course, 80% humidity is relatively high, but when I think about all the machines that are in Asia, without AC…
The 20C sounds ok to me (I drive with 20C but have less humidity and an ambient temperature of about 25C year round). As long as you can keep your tube at the temperature specified by the manufacturer, you don’t need to go any lower. However, it is an operational advantage to have a temperature that doesn’t fluctuate too much. My start/stop of the cooling compressor is at +/- 2C, i.e. 18-20C.
If you are concerned about condensation, just keep an eye on your tube, if there is no condensation in extreme weather conditions, you are on the safe side.
I haven’t quite understood that you might heat your workshop…
The dew point is, as a rule, theoretical in my opinion.
Very approximate but theoretical because there are always variables that we cannot control and that alter these results.
I have no experience with the behavior of these machines in excessive relative humidity.
I can calculate that as long as the machine remains in operation it will be difficult for moisture to accumulate to the point of creating operating problems. I admit that the problem is more after a period of rest, in which the machine was stopped, and when starting it, humidity exists or is created that can, at this stage, create some type of problem, the most serious being the electric arc in the tube.
I leave a link to calculate the dew point in case it is useful.
As an update, I created a dew point chart in excel for temp and humidity and coloured the cells in green, amber & red to show at what temp/humidity the dew point is under/close to/over the chiller temperature - which has given us a much larger range of temp and humidity to work with - basically all ok ion the green zone, be careful in the amber zone and not at all in the red zone!! Had the laser running successfully all day on Tuesday with high humidity and was able to do quite a few tests - including some surprisingly successful ones on some slate.