Most people believe that if something costs more, it has to be better quality. In the case of generic drugs, this is not true, says Gary Buehler, Director of FDA's Office of Generic Drugs. The standards for quality are the same for brand name and generic products..uch of FDA's review of generic drugs and brand name drugs is the same, Buehler explains (See Same FDA Requirements for Brand-Name and Generic Drugs below).
Then evaluate tank water heaters on the same gph basis to determine how many gallons of storage are needed to meet this demand. While tankless water heaters do not run out of hot water, if not sized correctly, the flow rate of that water can be adversely impacted.
Example: (From Holman, Heat Transfer 3rd Edition) Water with a mass flow rate of 30,000 lbm/hr is heated from 100 to 130 F in a tube and shell heat exchanger.A single pass of water at 15,000 lbm/hr and 200 F is used on the shell side as the heating fluid.xample: (From Holman, Heat Transfer 3rd Edition) Water with a mass flow rate of 30,000 lbm/hr is heated from 100 to 130 F in a tube and shell heat exchanger.