[Dale M.]

Originally Posted by Floorkasp

There are plenty of windows that open to let new air in, just not that many that fit the diameter of the aluminium flexible tube. And I'm hoping I don't have to make any new holes in the caravan...

Aluminum flex tube is probably the worst material you can use for actual duct.... Many people try to use it but the efficiency of how it moves air is greatly reduced by the turbulence caused by air bumping over corrugations of tube.... Smooths wall tube and formed turns are best solution for "air" ducting...

Diameter of tube is important because it determines how much air can flow through it.... Restrict the tube by "squeezing" it down and you restrict the efficiency of ventilation.... Actually the larger the diameter the better....

Your exhaust exit point should be at least 10 feet from your fresh air source (make up air)..

Exhaust exit can be at any height as air flow is a product of your fan and nature... Fan causes a slight low pressure (vacuum) in area and since nature abhors a vacuum, it rushes air in to fill that vacuum.... But better to be up higher as nature has more time to dilute the combustion byproducts and convert them to a way the impurities can be reabsorbed into "earth cycle"...

Best solution is to keep it short and as few turns as possible, so why not just make a hole in side of "caravan" (trailer to rest of us) above hood and go directly out.... Trying to accommodate the exhaust duct to go out a window or existing vent may not be practical as length and duct type ( be sure to use smooth walled duct) may restrict ventilation to point it is not effective and you are just creating tubular wall art...


Lots of thinks effect the efficiency of your ventilation, do your research well...There is actually a lot of science behind making it work effectively...

http://www.artglassanswers.com/forum...php?f=12&t=273
http://www.artglassanswers.com/forum...php?f=22&t=150

And in general....

http://www.artglassanswers.com/forum...dac36e4d422eac

Dale