Inspector 102
Silver Member
Given single family home with (2) 150,000 BTU/H tankless water heaters and (1) fireplace yet to be installed, the contractor has run 1/2" black iron to all appliances. I know this is way too small but am having trouble figuring pipe size needed. From meter to 1/2 tee, then 25 feet to first water heater, then 35 feet to fireplace. Other direction is 35 feet to second water heater. I see a total demand of 340,000 BTU/H potential with all appliances. Supply is natural gas at 1.5 psi I believe. How do I convert CF of gas to BTU/h calculation for pipe sizing.