Limitations on Use of 34 Watt, "Energy Saving" T-12 Lamps:

34 Watt T-12 lamps are not inherently energy efficient. They reduce wattage below that of a 40 Watt lamp, but also reduce light levels due to both a lower rated lumen output and a lower ballast factor.

When combined with an energy saving ballast, a 40 Watt T-12 not only produces more lumens, it produces more lumens per Watt than the 34 Watt lamp.

Intended primarily as a one-for-one replacement for 40 Watt lamps in an overlit environment, they represent one of the least aggressive energy efficient strategies for fluorescent systems. They are often not favored by utility rebate programs because they can be replaced with 40 Watt lamps over time.

The application limitations presented should be considered by the specifier/designer. In general, 34 Watt lamps perform poorly in low temperature or partial output applications. In addition, their potentially low efficacy (lumens per Watt) and output makes them a poor choice when reducing the number of lamps in a luminaire, or when an upgrade with new electronic ballasts could include T-8 lamps.

For both practical and economic reasons, 34 Watt T-12 lamps should not be used in the following circumstances, unless thorough evaluation and economic analysis has been done:

· With electromagnetic cathode cutout ballasts, low output ballasts, or two-level ballasts.

· In new construction or lighting system redesign.

· With retrofit reflectors.

· With delamping.

· With static controllers (such as current limiters).

· With dynamic controllers (such as dimmers).

· In lower ambient temperatures including air handling luminaires, especially when dimmed
or controlled to lower output.

· At starting temperatures below 60o F.