Ice Castle/Direct vent heater

[snowfighter]

Purchased a Empire direct vent heater to put in my Ice Castle.I know from a few years back when I installed one in a diffent house, there is a minimum wall measurement of 4 1/2" for venting. At that time I built the vent kit area out to meet that requirement. Wondering with other Fish houses out there with Empire direct vent heaters installed by dealer or factory if they have built out vent wall area to meet requirements or will it work with less wall thickness. My Ice Castle wall thickness is about 3 1/4.

[hawkeye43]

I built the wall thicker on the inside of the house on 3 houses. They work just fine that way.

[snowfighter]

I built the wall thicker on the inside of the house on 3 houses. They work just fine that way.

Thats what I planned on doing like the other one I installed.Mainly wanted to see what dealers/ house builders were doing,thought there maybe some kind of extenion kit out there. Contacted Empire tec support like I figured its the minimum distance to get vent draw for exhaust. Thanks