Operating in cold weather

[Walt Langhans]

My laser is in the garage, the garage is not heated and I need to have the door open 10 inches or so to get the exhaust tube out. We are going to be in single digit temperatures for the next few days. Not worried about the chiller it's had anti-freeze in it since day 1, but I'm concerned about the laser tube. Last winter we had a few days that it was below freezing here and there and I ran it and all was fine, but this single digit temperature has me concerned. Has any run there laser in conditions like this before?

Thanks!

[David Somers]

Walt,

I don't have a laser yet so no experience. But I did notice the Rabbit lasers I am considering all have an operating range that starts at 0 degrees C (32 F) which puts it well out of the temp range you currently face. I think the Rabbits had an operating range of 0 to 45 C or 32F to 113F. The other operating parameter was non condensing humidity levels.

Regarding the 10 inch gap under the garage door. For winter, have you thought of making a baffle for under the door?.... A 1 by 12 running the length of the door frame that you can put a fitting in for your vent hose? Then you can vent out but still seal the door, and perhaps run some heat in there when needed without feeling like you are paying the power company to melt snow?

Or, look for a post that Dan Hintz had done way back that just cropped up again. About a homemade filter costing under $200 that he has been quite pleased with. That might be enough to let you run with the door closed and the heat on? Check it out. It is currently an active thread so you should see it right away in the forum without having to search.

A last thought. I live in Seattle. We are not exactly the cold capital of the world. Today was 32 when I left the house for my bike commute and that is getting down there for us. Anyway....moisture can be an issue for us more often than cold. I will be tempted to put a small, 25 watt Golden Rod Heater in the laser cabinet to help keep the inside temp a few degrees above ambient and avoid any possibility of moisture condensing in there. You can get them in higher wattages, up to perhaps 100 watt I think? Anyway...that might help keep the laser closer to a safe starting temp on colder mornings? Anyone else in cold climates use a tactic like that? I use these little heaters all the time in small spaces where Humidity and mold or mildew is an issue. They are gold colored anozied aluminum tubes of various lengths. About 3/4 in thick? Pretty compact. They have brackets that come with them that allow you to mount them if you want. Google Golden Rod Heater or hit Amazon. Or if you have a boating store near you they will likely have them as well.

Good luck Walt!

Dave

[Bob McGinn]

Thermal Shock would be a concern. Check your manual for operating environment.

[brian saban]

The thing you would want to watch is the rapid change in temp, think of a glass. I don't think leaving it off in the garage is a major problem, but I wouldn't operate it till the temp in the garage warms up.

[Dave Sheldrake]

As the tube warms up you may face a condensation problem Walt.

I've run lasers at -12c but it isn't the best idea in the world unless you are very careful about thermal shock or condense.

The main way I deal with temp fluctuations is by leaving the machine pump running 24/7, the pump actually induces a small amount of heat into the water and keeps things nice and stable.

best wishes

Dave

ps: it also stops you forgetting to turn the pump on ;)

[matthew knott]

If you have antifreeze in the chiller then that would mean you have it running through the tube also would it not? Condensation can be an issue but it normally forms when you have something that is colder than the dew point, at the moment the dew point will be very low and your heating the tube so it should all be working in your favor, one thing to avoid is heating the room before the laser unless you wait for everything to come up to temperature. Think wearing glasses, from inside to out, no problems (unless your in a air conditioned, cold room), go outside to in, instant fog up.
Dave advise is sound, living the pump running will keep everything moving and stable, also i would try to find something to block the gap under the door, just to try and keep some of the heat in the garage. We never let the temperature drop below about 50 f where we run the lasers and thats 24/7

[Walt Langhans]

Thanks guys!

It's not normally this cold here so it's not like I need to set things up to run in this kind of environment for a regular basis. I typically work on the weekends as well as the week, so the heck with it, I'm just going to play it safe and take the day off. Woot snow day haven't had one of those in forever!