SUNY Oneonta Weather Camera
The camera lives in a custom-designed and -built enclosure on the roof of Milne Library.
We needed to create a space that is not physically attached to the roof and provides basic environmental control for the camera.
The base is cast concrete to offer a mass that prevents the structure from moving in anything less than hurricane-force winds.
The tower is welded steel that is bolted to the concrete base.
The enclosure box is 3/4" wood, painted white on the outside and battleship gray on the inside.
The Polycarbonate dome is bonded to a Lexan disk which is in turn bolted and screwed to the enclosure, and the disk has a silicone drip-edge to keep water away from the Lexan-wood interface.
The white port on the left is a toilet flange that acts as an exhaust port for the internal vent fan assembly. It has a piece of screen inside to keep insects out.
The orange cable supplies power to the environmental systems. The black cable carries data and power to the camera.
The underside of the enclosure, showing the cooling air intake port and the temperature sensor.
The interior setup. The camera is bolted to a reclaimed steel L-bracket. The heater assembly is in the upper right, the indoor-outdoor thermometer in the lower left, the cooling thermostat in the foreground and the cooling blower under the camera.
The heater is a fish aquarium heater immersed in an old aluminum drink bottle filled with mineral oil.
The red stuff is fire-resistant putty to seal the edge and prevent mineral oil vapor from condensing on the inner surface of the dome.
There is a thermostat on the aquarium heater that shuts the heater off when the mineral oil reaches 90 degrees.
There is a second thermostat in the enclosure that switches the power on when the temperature under the dome falls below 32 degrees F / 0 degrees C, and turns it off when the temperature is above that value.
The mineral oil acts as a thermal reservior and the aluminum bottle conducts heat efficiently to the air in the enclosure.
The thermostat is wired into the heater power and bolted to a reclaimed bracket which is screwed into the side of the enclosure.
This takes care of things when it gets cold. Even on the worst subzero days the enclosure (and hence the camera) temperature will not fall below 32 F / 0 C.
We take the heater assembly out in the summer.
Meanwhile, there is another thermostat mounted to the side wall of the enclosure.
This one is variable but is set to close a circuit when the temperature inside the enclosure rises above 80 degrees F / 27 degrees C.
When the circuit closes, the blower (a repurposed bathroom vent fan) starts up and blows air out of the enclosure at a high rate.
This puts the enclosure under negative pressure. Air is allowed to pass up through the PVC pipe from the base of the enclosure.
It is ducted up and across the inside of the dome. The short piece of yarn will wig-wag in the air stream so that the camera can confirm its operation.
This keeps the camera cooled to at least the outside ambient air temperature on a warm day.
The cooling blower assembly usually will not run in the winter months.
That's about it. Mostly homebuilt in a garage out of bits and pieces.