Water Heaters - water heater selection

:wall: I need a little help in selecting the "right" gas water heater. We've decided to replace the existing 40 gal heater with a 75 gal unit to accommodate our 3.5 baths and 50 gal whirlpool. The problem is which confirguation is optimum.
Unit A specs are: 55k btu, 54.8 gph recovery @ 90 degrees,1st hr 114 gal.
Unit B specs are: 76k btu, 78.0 gph recovery @ 90 degrees,1st hr 138 gal.
The wife thinks unit A is more economical as it burns less gas.

Jorge

by the way, the units are Sears Kenmore and Bradford White respectively.

Assuming everything else is equal, they will both use the same amount of gas. Unit "B" uses more gas when it's operating but it will be on for a shorter period of time. Unit "A" will have to stay on longer to heat the water.

The yellow Department of Energy tag will tell the story of efficiency. I think they are still required on every water heater. Since you are comparing two 75-gallon units, the tag will show what the typical cost is to heat the same amount of water in a year. Lowest cost wins unless the purchase price is way higher on the more efficient one. If the yearly savings difference times about 2.5 is equal to or more than the difference in purchase cost (assuming the higher efficiency unit costs more) then buy the more efficient one. I'd bet on the BW.