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.
To calculate the size water heater you need, evaluate capacity versus consumption. Compare water tank capacity or continuous flow rate to peak usage rate. Showers are the key. Multiply the showerhead flow rate by the average length and number of showers in a given period of time. Choose a water heater with capacity to match.