30 Watt, 8 inch "Cool White" Circular Lamp Source

Try this site, they seem to have quite a selection. I wouldn't be too concerned with the wattage (30W old vs 22W new) I think they are just making them 'energy-saving' now.

Brad & Michael-

Doesn't the ballast determine the Wattage? If so, the 22 Watt lamps may be bright enough, but not last as long as the 30 Watt lamps.

I don't recall ever seeing a 30 Watt 8 inch circular lamp. What company made the fixture? Perhaps they have a retro-fit kit that would adapt the fixture to use the more commonly available lamps?

Fred

Perhaps. but I have seen preheat type ballasts labeled 15W-18W-20W, so I don't think it is that critical.

If it were me I would replace the whole fixture. If he absolutely loves the circular tube lamps, he could replace the ballast with a rapid start electronic ballast. That would promote longer bulb life, and probably provide more light output.

Those run all the lamps at around 15W, it's not critical, but you do want to stay within a reasonable percentage of the nominal wattage printed on the lamp. Many inexpensive "40W" fluorescent ballasts actually run the lamp at closer to 25W which is why they're so dim compared to a good ballast.