Water chiller for cooling a CO2 laser tube

Which Laser Chiller Should You Buy? (And What to Avoid)

For an 80W CO2 laser in daily use, buy a refrigerated chiller: a CW-5200 or a CW-5200-compatible unit, set to around 18 °C. Don't rely on a CW-3000. It's a passive cooler that can't get the water below room temperature or hold a setpoint. OMTech machines ship with a water pump, not a chiller, so budget for one.

The chiller is an easy part of a CO2 laser setup to get wrong, and an expensive one. Not because a chiller costs a lot, but because the wrong one can shorten your laser tube's life, and you may not realise the chiller was to blame until you've replaced the tube.

Cooling is one part of a bigger picture. If you're still working out how a CO2 laser does what it does, our explainer on how laser engraving works covers the fundamentals. This guide covers what to buy for a single machine, what we run for our two machines, what to avoid, and how to set it up once it arrives.

Why cooling matters

A glass CO2 laser tube like OMTech's generates heat every time it fires, and that heat goes into the cooling water circulating through the tube. If the water temperature creeps up during a long job, the tube runs hotter than it should. In our experience, warm water is one of the commonest ways to shorten tube life.

The goal isn't just to cool the water. It's to hold a constant temperature however long the machine has been running and whatever the room temperature is. That's the difference between the right chiller and the wrong one.

We've run OMTech CO2 lasers in daily production since January 2023, and two of them since June 2024. We run both at a constant 18 °C. In our view that consistency is part of why the older machine's tubes have averaged about 13 months each, mostly cutting at high power, and the newer machine's first tube lasted about two years. Owners with poor cooling report much shorter tube lives.

The one to be careful with: the CW-3000

For an 80W machine in daily use, or any workshop that gets warm, skip the CW-3000.

The CW-3000 is a passive cooler, not a refrigerated chiller. It has a radiator, fan and pump but no compressor, so it can only bring the water towards room temperature, never below it. Teyu, which makes S&A chillers, rates it at 50 W/°C: the water sits about 1 °C above room temperature for every 50 W of heat it takes in. It has an over-temperature alarm, but no way of holding the water at a set temperature. S&A rates it for CO2 tubes below about 80W, so it's not the right choice for an 80W machine running all day.

We've seen Amazon listings that bundle the CW-3000, CW-5000 and CW-5200 as variants on the same page. Don't order the CW-3000 by accident thinking it's equivalent. This type of listing is the trap: check which variant is selected before you add it to your basket. We link it as an example of what to check, not as a recommendation for an 80W machine.

What you actually want: a CW-5200

The CW-5000 and CW-5200 are refrigerated chillers. A compressor actively cools the water and, in constant-temperature mode, holds it at your setpoint to about ±0.3 °C, whatever the room temperature. S&A quotes about 1.4 kW of cooling for the CW-5200 and rates it for glass CO2 tubes up to 130W. OMTech recommends a CW-5200 for 50–100W machines, and sells one for about £420 at omtech.uk (October 2026; check the current price).

For most single-machine owners: a CW-5200-compatible chiller

If you're running one CO2 laser for business or serious hobby use, you don't necessarily need the S&A-branded unit. This CW-5200-compatible chiller is listed as 6L, 220V and rated for 50W–130W CO2 tubes. It costs less than the branded unit, and for most single-machine setups it's what I'd suggest.

If you want the branded unit: S&A CW-5200TH

S&A is Teyu's brand, and the CW-3000, CW-5000 and CW-5200 model numbers are Teyu's; "compatible" units copy them. The S&A CW-5200TH is refrigerated, has a 6-litre tank and is rated by S&A for glass CO2 tubes up to 130W; the "T" means it runs on 220V at 50 or 60 Hz. It looks similar to the compatible units and may well perform similarly. Buy it if you want the original maker's name; in my view S&A's after-sales support is the better bet too.

Either option is a better fit than a CW-3000 for an 80W machine. The choice between them comes down to budget and whether the S&A name matters to you.

Check your warranty first. OMTech UK's warranty terms (checked October 2026) exclude faults caused by not using an OMTech-supplied water pump or chiller, and alterations or servicing by anyone OMTech hasn't authorised. If your machine is still under warranty, check with OMTech before swapping the chiller, pump or other parts. OMTech UK sells a CW-5200 itself, so buying from them is the straightforward route while you're covered.

Our setup: one S&A chiller for two machines

We run a single S&A chiller that cools both our machines at once. If you're running two machines and want to simplify your cooling, S&A sells a dual-circuit model, the CW-5202, which has two separate water inlets and outlets for cooling two CO2 tubes from one refrigerated unit.

How to set the temperature, and what to set it to

We run ours at 18 °C. OMTech recommends keeping the cooling water between 16 °C and 21 °C. Too warm and you lose the benefit of proper cooling; too cold and you risk condensation on the tube.

18 °C works for us most of the year. On hot, humid days, though, the dew point in a UK workshop can rise above 18 °C, and water at that temperature will make the tube sweat. On those days check the tube for condensation and nudge the setpoint up a degree or two if you see any, staying within OMTech's 16–21 °C range.

Setting the temperature on a CW-5200 isn't obvious from the manual. S&A chillers have an "intelligent" mode, where the water tracks room temperature, and a constant-temperature mode; to hold a fixed setpoint like 18 °C you need constant-temperature mode. This video walks through it clearly. It's not ours, but it does the job:

How to set the temperature on a CW-5200 chiller (YouTube)

Other chiller tips

  • Use distilled or deionised water only. Tap water leaves mineral deposits in the tube over time. Teyu recommends changing the water every three months.
  • Check and top up the reservoir regularly. Low coolant reduces flow and raises the temperature. It takes thirty seconds to check.
  • Protect it from frost. Freezing water can crack the tube's water jacket, and OMTech doesn't cover freeze damage. If your workshop can drop below freezing, drain the system or use a laser-specific antifreeze coolant at the maker's ratio, and flush back to distilled water in spring. Never use car antifreeze, which is conductive and corrosive.
  • Let it reach temperature before you start the laser. Give it five minutes to stabilise, particularly on a cold start in winter.

Our CO2 laser maintenance guide covers the weekly and monthly routine around the chiller, and the pre-delivery setup checklist covers space, power and ventilation before your machine arrives.

See our setup before you buy

Both our machines, and the chiller that cools them, run every working day at our workshop in Buckley, North Wales, which is also an official OMTech showroom. Visits are free, informal and by appointment: email info@cherrygrovecraft.co.uk with a couple of dates and come and see how it's all set up. When you're ready to order a machine, our OMTech discount code Cherrygrovecraft takes 4% off at omtech.uk (checked October 2026).

Frequently asked questions

What is the best laser chiller to buy for a CO2 laser?
For a glass CO2 tube of 50–100W, a refrigerated CW-5200 or a CW-5200-compatible unit; OMTech recommends the CW-5200 for that range. Check the chiller's rating covers your tube's wattage and that it can hold a fixed setpoint. If your machine is under OMTech UK's warranty, check with OMTech first: its terms exclude faults caused by not using an OMTech-supplied water pump or chiller.

Which laser chiller brands are considered the most reliable?
S&A, Teyu's brand, makes the original CW-5000 and CW-5200 designs that "compatible" chillers copy, and it's what we run on our two machines. We can't rank every brand from one workshop; whichever you buy, choose a refrigerated unit rated for your tube.

Is a CW-3000 chiller enough for an 80W CO2 laser?
Not for daily use. The CW-3000 is a passive cooler with no compressor, so it can't cool the water below room temperature, and S&A rates it for tubes below about 80W.

What temperature should a CO2 laser chiller be set to?
We run ours at 18 °C, and OMTech recommends 16–21 °C. On hot, humid days check the tube for condensation and raise the setpoint a degree or two if you see any.

Can I put antifreeze in a laser chiller?
Only a laser-specific antifreeze coolant at the maker's ratio, flushed back to distilled water in spring. Never use car antifreeze, which is conductive and corrosive.

Disclosure: some links on this page are affiliate links, and we earn a commission from OMTech on purchases made with our code or link. It costs you nothing extra.

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