Fresh air intake on enclosed trailer heater

[M8highrider]

I have seen some install their heater with the fresh air intake in the enclosed part of the trailer and some port it to the outside.
Pros and cons of one way or the other? Is there an air quality danger to allowing the heater to get its air from inside the trailer?

Thanks for all sensible thoughts...

 

[MT boondocker]

What I found out was that if your furnace drew fresh air from outside and vented exhaust outside that you didn't get moisture inside your trailer like you will do with the non-vented heaters.

 

[M8highrider]

Thanks, that makes perfect sense. I had not thought about that aspect. I was wondering whether it would make the heater more efficient at all by recirculating the warm air, but I would rather not have the moisture in there if I can help it.

 

[meathooker]

depending on the unit most heaters are only rated at 40-60deg temp rise. if you're pulling outside air and its 0deg outside you'll only get the inside of the trailer to 40deg. mine is a factory installed trailswest with a return inside the trailer and in 10 min or so the inside is 70deg. after a ride when we're drying gear/sleds out i pop open the rear most roof vent and that helps with the condensation. most heating engineering guidelines only call for 10-15% outside air, so if you wanted to duct a small run with a damper installed that would be a good compromise imo.

 

[onepicknick]

Are you going with a rv heater? I do home energy audits and I'll tell you why you'd vent your woodstove to the outside. Think about where the oxygen is coming form to fire your stove which in turn is air if it's from the inside it has to be replaced how is it replaced from the outside so now were sucking in cold outside air and burning our warm inside air makes no sense. Now if we burn the outside air now were creating a bubble affect and pushing warm air outside and if tight enough it holds heat longer now we don't have the cold air coming in so in a insulated trailer it has benefits if not six of one half dozen of the other.

 

[xcbuc22]

I decided not to install a fresh air line from the outside on my rv forced air furnace. My trailer isn't insulated so I figured there would be a little fresh air from small cracks/holes. Like meathooker mentioned, if all the fresh air is really cold, the heater isn't going to work as efficient.
Good topic here on this thread: Trailer Ducting Install This Weekend