Separate Combustion question

[zchrisz]

I'm looking to install a propane heater and i was going to go with the modine hot dawg hds 45 because of the separate combustion, i was looking at the sterling garage guy and it can be made in to separate combustion using the concentric kit, how is this possible?? and if it can be done on that, why not the regular hot dawg models?

 

[rickairmedic]

The HDS can use a concentric vent where it draws combustion air from outside through the outer pipe of the concentric and exhausts through the center pipe in the concentric vent . This means that all of your combustion air is being drawn from outside the building. Most tankless water heaters use this system as well . The regular hotdog is not designed with a sealed combustion chamber which is why a standard hot dog cant be setup that way .


Rick