Greg wrote:jpingram5, MH approved units draw combustion air from the OUTSIDE not the interior of the home as a conventional home unit. Should a backdraft happen the carbon monoxide will be directed outside the home not into it.
Are companies that manufacturing MH approved units ripping us off? Maybe, but you are also paying for an insurance policy when you buy one.
Yes, you are completely correct about the MH units drawing air from outside. And yes, SOME conventional units draw air from inside, but there are also units that draw from outside. The danger you causing is insurance issues if a problem occurs. Which is something you need to think about.
That's why you get a Direct Vent system & Sealed Combustion. That means it draws fresh air from outside & sealed combustion meaning it won't draw air from inside. It's a sealed chamber. I started comparing a lot of MH stuff to conventional when I went to switch my AC for a HP and it was outrageous. I got a conventional setup that works perfectly fine for about $1,000 less then what I would have payed for the MH certified one. What's the difference you wonder? The coil was a little bigger but I fabricated a custom cabinet for it and it didn't have a plate that said it was HUD approved for manufactured homes. That's it, nothing unsafe about it. My Rinnai tankless LP water heater is direct vent sealed system and is officialy now certified for MH use. Why was it certified? Because now you can buy a conversion kit for LP & NAT for it. As long as it is sealed combustion direct vent you will be fine.
I'm not trying to convince people to use equipment not certified, but he wanted to know what's the difference and that's what I'm trying to explain. There's not much of difference except one violates your insurance policy and the other doesn't.