W/H clearance & gas pipe sizing

[DualCombustion]

Hello,

Is there a code requirement for the clearance for a W/H? I am moving my W/H and just want to be sure befor I start building the walls (I plan to leave clearance for other size W/Hs, just want to know if code has anything to say about it...

Also, can anyone recomend a good website with gas pipe calculation tables? I have done the calcs before and don't have a copy of the table.

Thanks
[DC]

[mdshunk]

Gas water heater or electric?

The water heater clearances would be in accordance with manufacturer's instructions. The code does state that as gas fired water heater located in a sleeping room or bathroom must be located in a totally sealed "room". The code does specify that gas fired water heaters in little "rooms" must have 2 vents, one high and one low. If the water heater's sealed room is in the sleeping room or bathroom, the vents must be to the outdoors. If in any other location, the vents can be to the indoors (such as a high and low louver in the door to the room). There's lots of code related to clearances to the vent and stack.

[DUNBAR PLUMBER]

http://www.uscarb.com/natural-gas-chart.htm