gar
Senior Member
- Location
- Ann Arbor, Michigan
- Occupation
- EE
141226-1012 EST
For Christmas my son gave me a Feit 4 foot 2 bulb LED Utility Shop Light from Costco, about $ 40.
The box says 38 W, 3700 lumens, 50,000 hours, 4100 K cool white, lasts 45 years, saves $ 275 in energy costs, and based on 2 hours per day and $ 0.11/kWh.
Measures 37.8 W and 0.99 PF at 123 V. With a Variac visual brightness is constant from less than 100 V to 140 V, and dimming starts at about 60 V. Dimming with a sine wave is fairly good, but light won't restart at low voltage. Requires about 50 V to start. Whether driver damage occurs at low voltage, within dimming range, I have no idea. Also have not tried a phase shift dimmer.
Brightness at 4 ft is better than my 8 ft Slimline. I haven't done a light meter comparison yet.
My son plans to replace a number of Slimlines with these Feit fixtures. In recent years 8 ft T12 bulbs have not been lasting long, and many GE bulbs from China have been bad out of the box. Even with some expected early failures with the Feit fixtures, and shorter than claimed life, they will probably be less expensive than T12 bulb replacement. Roughly speaking energy cost is cut in half, and we pay about $ 0.16/kWh.
$40 at $0.16/kWh is worth 250 hours. At a ballpark saving of 50 W per fixture this is equivalent to 5000 hours. At 14 hours per day that is about 1 year of operation. I would expect average life to be greater than 5000 hours.
.
For Christmas my son gave me a Feit 4 foot 2 bulb LED Utility Shop Light from Costco, about $ 40.
The box says 38 W, 3700 lumens, 50,000 hours, 4100 K cool white, lasts 45 years, saves $ 275 in energy costs, and based on 2 hours per day and $ 0.11/kWh.
Measures 37.8 W and 0.99 PF at 123 V. With a Variac visual brightness is constant from less than 100 V to 140 V, and dimming starts at about 60 V. Dimming with a sine wave is fairly good, but light won't restart at low voltage. Requires about 50 V to start. Whether driver damage occurs at low voltage, within dimming range, I have no idea. Also have not tried a phase shift dimmer.
Brightness at 4 ft is better than my 8 ft Slimline. I haven't done a light meter comparison yet.
My son plans to replace a number of Slimlines with these Feit fixtures. In recent years 8 ft T12 bulbs have not been lasting long, and many GE bulbs from China have been bad out of the box. Even with some expected early failures with the Feit fixtures, and shorter than claimed life, they will probably be less expensive than T12 bulb replacement. Roughly speaking energy cost is cut in half, and we pay about $ 0.16/kWh.
$40 at $0.16/kWh is worth 250 hours. At a ballpark saving of 50 W per fixture this is equivalent to 5000 hours. At 14 hours per day that is about 1 year of operation. I would expect average life to be greater than 5000 hours.
.
