Jump to content

SCT Cooling fan and high humidity


Recommended Posts

Seeking to be able to get my Celestron C8 cooled and usable in a reasonable time (similar to my reflectors), I have:

  1. made a BAA Kitchen table collimator
  2. got SWMBO made a reflectix insulated tube jacket
  3. Bought a Lymax SCT cooler from the U.S.A.

The Lymax Cooler arrived on Friday, and I note that the instructions say:

  • Do not use the cooler in a heavy dew
  • Do not use the cooler in high humidity

What constitutes a heavy dew and/or high humidity? Does anyone else use a FAN to cool a telescope in the UK?

Where I live the % humidity is usually above 85% and it is very rare that the grass is not wet in the morning. I was going to use this last night, but the % humidity was over 90% and the grass was already wet, so I used my SD115S instead.

Thanks.

IMG_20240728_172159783.thumb.jpg.a055bbc69a780dc9ee085ea5968ffb48.jpg.

Link to comment
Share on other sites

I think if the ambient temp is very close to the dew point that is when you don’t want to use it… as by forcing that ambient air into the tube then you’re risking your mirrors and inside do the corrector dewing up. 
 

With the insulation I wouldn’t think you’d need to use active cooling. The point of the insulation is to keep the air temperature in the tube stable - it may be a lot warmer than ambient but if it is stable then there will be no air temp deltas and no tube currents to ruin the views. So if you’re forcing outside air inside the tube then it kind of defeats the point of the insulation. 

  • Like 3
Link to comment
Share on other sites

It looks like you have insulated your scope so if done correctly ( a C8 will need two layers ) there is no need to cool the scope and corrector dewing becomes less of a problem 👍

Edited by dweller25
  • Like 1
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.