edubb
Active member
Thought I'd pass this along for general info. Our trailer has an Attwood 20K BTU furnace, pretty typical I'm sure. But Forest River designed the trailer with two 4" heat ducts, and one 2" duct. The 2" is worthless, and the Attwood manual says it doesn't count toward the required minimum 24 square inches of exhaust duct. So we have the minimum required (two 4"). When I first saw this I almost laughed. Heat a 26' trailer with two 4" ducts!!
When we camped in low 20 degree temps, I could tell the furnace was working harder than it should have to (it would cycle the gas on and off while the blower stayed on, I'm sure the furnace "firebox" reached max temp cutoff before the trailer reached full temp--in other words the furnace couldn't move the hot air out fast enough).
So long story short, I added another 4" heat duct run. Had to relocate the fresh water tank slightly, move an electric outlet and the LP detector, but I got it done, and it works great! All three 4" outlets blow hot air like crazy, so I was right to assume it could move more air. The test is this weekend, we will camp at 4000', should be below freezing at night.
When we camped in low 20 degree temps, I could tell the furnace was working harder than it should have to (it would cycle the gas on and off while the blower stayed on, I'm sure the furnace "firebox" reached max temp cutoff before the trailer reached full temp--in other words the furnace couldn't move the hot air out fast enough).
So long story short, I added another 4" heat duct run. Had to relocate the fresh water tank slightly, move an electric outlet and the LP detector, but I got it done, and it works great! All three 4" outlets blow hot air like crazy, so I was right to assume it could move more air. The test is this weekend, we will camp at 4000', should be below freezing at night.