Rank: Forum user 
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Hi all,
Im looking for some info/advice.
In order to reduce risk from HAVS, we have recently changed from using electric angle grinders to comp air versions. However, there is a significant amount of cold air coming from the exhaust of the tool.
This causes a chilling effect to the operators hands. This would not normally be a significant problem however, he has Stage 1 HAVS which makes the situation/condition worse.
The Occ Health Doctor has said he can continue in his normal duties as long as monitor his exposure.
I was speaking to a colleague who said he has seen cloth bags on the end of air tools which, I suppose, diffuses the cold air, reducing the chill effect.
I have seen mufflers which apparently can also diffuse the cold air but I have never had to use these either.
Has anyone came across this issue or know of a solution?
Thanks in advance
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Rank: Super forum user
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The air from a compressed air tool will always be cold. This arises from the fact that much of the the energy required to compress the air is changed into heat in the air. The compressed air then cools (aftercooler to remove moisture, distribution pipework, etc.) so that when the air expands on emerging from the tool it acts in the same manner as the fluid in your refrigerator, i.e. becomes very cold. One way in which this cooling effect on the operator's hand can be reduced is to fit a sintered metal silencer to the air tool. This not only reduces noise but also tends to have a diffusive effect.
Is there any moisture in the emitted air. If so, then this will exacerbate the feeling of cold. If this is the case then you need to take a look at the post compression air treatment to ensure that the compressed air in the pipework is really dry.
As someone who, many years ago, worked in the compressed air field, I sometimes fitted a small, angled pipe to the exhaust and then the silencer. This directed the air away from the operator's hand. Otherwise when use is for an extended period the only answer I was able to find was for the operator to wear an insulating glove on the affected hand. However, this was a long time ago and others may have found better solutions since.
I recall that one of my customers at the time actually fitted a heater system around the pipework to heat the air just upstream of an air system as the cooling effect would have affected the actual process for which the compressed air was required.
Chris.
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Rank: Super forum user 
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Tool selection and design also important - exhaust ported away from the operator. Sometimes an issue for left-handed people.
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Rank: Forum user
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Hi all,
Thanks for the information.
We have carried out trials last week and found that the exhaust air is so cold is causing frosting on the handle and casing of the tool.
We are unsure if this is related to the air dryer on the compressed air system or the humidity of the workshop. My guess is the air dryer not being very effective at removing moisture from the system.
Nonetheless, it does illustrate how cold the exhaust air is and although we can solve the air dryer issue, this will not resolve the exhaust air temperature issue.
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