a direct vent water heater is more fuel efficient (cost's less to operate). aside from that there isn't much difference, aside from not needing a double wall flue through the roof on a standard gas water heater.
yes there are direct vent gas water heater available Absolutely NOT
When you cannot use B vent to find a way to vent the HWT through to the roof!
No. Gas water heaters are not all designed to use direct venting.
No it can not.="h2headingh2"style="color:rgb(0,0,0);"name="hell_no">
No, directly vents through to outside wall of building.
Depends on what type of vent system water heater has.
P.F Edwards has written: 'Direct vent water heater test' -- subject(s): Gas Water heaters, Testing, Water heaters, Gas
B-vent pipe.
yes it can
My direct vent furnace pilot light issue was the glass viewing port was missingallowing room air to blow out the pilot light. Replacing the missing glass which stopped the draft, fixed the problem.
Generally, a direct vent must be next to an outside wall or be connected to a chimney that extends 2-4 feet above roof peak (all gases and fumes from the burner will vent naturally). A power vent is used when the unit is put inside the home in a closet or on an interior wall. It must have venting to an outside wall and must have a blower fan to remove gases from the water heater so they don't back up into the house.