Welcome to LE.
LE has a wonderful search tool that is at the top of your screen. On my monitor, the background is red. Look at the line that says "UserCP FAQ Members List/RAOGK... to the far right is "Search." Just click on Search and a drop down box will appear for you to type the topic in that you want to search. For example, "ventillation" and then LE will search for any threads that have the word ventillation in it. For words with 4 or less letters, you have to use the * as a wild card. For example: red*
This can really help because it will bring up threads that may have already discussed your exact problem and the answer may already be here somewhere.
EDITED TO ADD: This is just one thread that I found. I haven't read all the way through but it's a start... perhaps something here will lead you to an answer.
http://lampworketc.com/forums/showth...t=ventillation
Best of luck,
Sue