Dew on optics in a dome

[Logieberra (Logan)]

Originally Posted by strongmanmike

Hi Logan

yes I will likely do the same if I get 240V connected...because we are renting and digging some long trenches though garden beds etc isn't realistic or appealing, I'm thinking of simply running an extension lead through a garden hose and leaving it out on the ground 24/7..?

Mike

Mike, if you go dehumidifier route - consider a DeLonghi (Type CF08E). I grabbed one from the Harvey Norman Bargain Basement in Fyshwick after a glowing report from CDKPhil on this forum. We grabbed the factory refurbed ones and saved quite a bit.

He uses the external water removal via user supplied tube. I use the internal bay only (both are possible, see pics). Many settings, speeds etc. They don't miss a beat.

A few pics here:

[Logieberra (Logan)]

In the 2nd pic, that yellow thing to the left is an auto-cutoff feature. The foam raises with water level and turns it off before overflow.

In the 4th pic, that disc can be pushed out to provide access to the water tube if you wish to re-route outside the observatory (5th pic).

The only caveat - a small modification is required to run the unit on a timer. Normally, you would have to manually press the 'on/off' button (1st pic). As said before, we use a timer to automate dew removal. A small soldering job fixes this and means that when the timer powers the unit, the unit turns on without user interaction. A simple 5min soldering job, easily reversable and does not damage the unit.

[strongmanmike (Michael)]

Nice one Phil

The operating temperature for that model is +2C to +38C, many days in Canberra it is below 2C for half the day..? It might need a temperature operated switch incorporated..? I think the desiccant models still work when it's colder..?

Mike

[Logieberra (Logan)]

During operation it raises the room (or observatory' s) temp slightly. In a small, contained space this makes quite a difference. No issues to date, regardless how cold the night.