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So are you all saying that the input air for the light tubes are from the cold outside and if so isn't the air from outside in the winter to cold to be going over the hot lights. Will it not possibly break them? Also how do you keep the cold air from condensing as it get warm from the lights? Wouldn't it be better if you just took air from inside the warm room?
Pepper
5th October 2006, 07:50 AM
Since there is a pressure drop at the intake side, there can be issues with condensation, especially on the first light. I have seen people solve the problem by allowing the intake duct to droop and punch a small hole at the lowest point for the condensation to drip out. The heat from the lights actually helps the air hold more water as it gets warmed up.
salmayo
5th October 2006, 11:18 PM
So are you all saying that the input air for the light tubes are from the cold outside and if so isn't the air from outside in the winter to cold to be going over the hot lights. Will it not possibly break them? Also how do you keep the cold air from condensing as it get warm from the lights? Wouldn't it be better if you just took air from inside the warm room?It is a consideration, but rapid changes in temperature are usually the cause of thermal shock caused by one part of the bulb's outter envelope being a different temp than another. The air temperatures in my area get down to 28F. Since my system is a Pusher (towards the hood) that is pulling outside air in, it's under negative pressure before the fan conpaired to the room and leaking or just openning that duct to the room's air can be used for controlling the fans intake air temp. On the "cold" side of my ducts I play with cheap cardboard manifold and slide type valve pieces to ajust flow/temp.
I would like to build a slide valve box so I can switch my winter and summer arrangements with one movement of the slide, which would allow for reversing the flow in the system to handle things like exhausting in house smoke from the kitchen and what not.
If you do use warm air from "inside the room" it would be a good idea to make sure it's from an odor free area to avoid pumping odors to unwanted places.
You make an excellent point about condensation Soulmate.
I'm considerring a condensation trap on my rig. Condensation could occur on a Pusher system like mine in the cool positive pressure area between the fans outlet and the hoods inlet. Since water flows downhill it will gather at low points. Using a droopping duct with a plastic PVC "T" at this point allows for a "drip catcher" at this point. If you connect the "drip catcher" "T" to a sealled bottle top, you can make a leak free condensation trap. I'd use a BALL brand canning jar lid (already has a big hole) RTV'd (glued) to the "T" and a jar, and I could see any water that collects. If I'd see water gathering in the jar I'd just unscrew the jar from the lid, dump it and screw the jar back into the lid. If you really wanted to dehumidify the air you could cool such a jar to force condensation within. I'm more worried about electrical shorts or maybe a drop of water striking the bulb and breaking it, than dehumidifying the air.
http://www.treatingyourself.com/vbulletin/archive/index.php?t-16175.html