ZWO 533MC Pro cooling

[Rob Astro]

Simple question I hope. If I cool my camera to -10. Is that actually -10c or 10 degrees below ambient?

[Vroobel]

Hopefully, it's -10*C, but it depends on your ambient temperature. Usually it cools the sensor 30-35 degrees below the ambient temperature. 

[900SL]

If using asi air pro etc to control, its -10c. You can confirm by looking at the screen bottom left, which shows the sensor temp.

Note that the max cooling is around 30 degrees below ambient, and it is not advisable to operate for length at more than 80% cooling. I often operated at 0C as there isn't a lot if dark current with the 533 sensor

Edited May 15 by 900SL

[Clarkey]

10 hours ago, 900SL said:

it is not advisable to operate for length at more than 80% cooling

This is a new one on me. Where is that from? Surely the manufacturers would design to allow full cooling without damage to the camera? Personally, I never get near to 100% as I do not image in the summer, but inquiring out of interest.

[900SL]

52 minutes ago, Clarkey said:

This is a new one on me. Where is that from? Surely the manufacturers would design to allow full cooling without damage to the camera? Personally, I never get near to 100% as I do not image in the summer, but inquiring out of interest.

I quote '

Peltier cooling: The lifetime limiting parameter on most metal to ceramic bonds is the number and magnitude to thermal cycles. The higher the delta T, the shorter the life. A rule of thumb is that for every 10 degrees centigrade, lifetime gets cut in half'

Also thermal shock may be higher on disconnection. Plus, and this may be more important,  if you run maxed out, any further drop in temperature may change the sensor temp as the peltier has nothing left in reserve

There was also some debate as to whether the 2600 oil-on-sensor issue was exacerbated by running coolers at 100% in hot climates

A quick google search will throw up some data.

My take is to err on the side of caution. However, because I live in finalnd, I often cool to -30C as it is only delta 15C   When I was in Saudi I didn't go below 10C 

[Tomatobro]

If you are using Sharpcap or other real time control software its the actual temperature you set it at. So setting it to -10 means its running at -10 and not ambient -10.

[Clarkey]

1 hour ago, 900SL said:

I quote '

Peltier cooling: The lifetime limiting parameter on most metal to ceramic bonds is the number and magnitude to thermal cycles. The higher the delta T, the shorter the life. A rule of thumb is that for every 10 degrees centigrade, lifetime gets cut in half'

Also thermal shock may be higher on disconnection. Plus, and this may be more important,  if you run maxed out, any further drop in temperature may change the sensor temp as the peltier has nothing left in reserve

There was also some debate as to whether the 2600 oil-on-sensor issue was exacerbated by running coolers at 100% in hot climates

A quick google search will throw up some data.

My take is to err on the side of caution. However, because I live in finalnd, I often cool to -30C as it is only delta 15C   When I was in Saudi I didn't go below 10C 

Ok thanks. Interesting to know.