Posted by Sheila 1 year ago In:

energy, lighting

Sheila Asked About 'Old Light Bulbs Made Into Oil Lamp » Coolest Gadgets'

Is wattage directly cumulative in lighting?

Which provides more light to a room - two 75 watt bulbs or a single 150 watt bulb? Is the energy consumption the same either way?

Answer this question

Liked this question? Tell your friends about it

Facebook Windows Live Yahoo Twitter Digg Google del.icio.us Reddit

Link

Embed

Copy and paste the text above to share this Q&A

2 Answers

Order by: Oldest to Newest; Newest to Oldest; Votes

PGroot Answered:

Wattage is not exactly proportional to lumens (a measure of brightness). A single 150 watt incandescent bulb is rated at 1500 lumens, or 1700 lumens, 1750 lumens, or 2450 lumens, or 2740 lumens, depending on the make and model, and that's the initial lumens. The brighter two are normal life (750 hours), the dimmer ones are long life.

A 75 watt incandescent might be 700 lumens, or 790 lumens, or 850 lumens, or 530 lumens (long life).

Energy consumption is directly related to the wattage, so one 150 watt bulb takes as much power as two 75 watt bulbs. But the 150 watt bulb might be as bright as three 75 watt bulbs (more efficient).

If you are concerned about energy, the 18 watt CFL advertised as 75 watt replacement says it has long life (10000 hours) and 1200 lumens initial brightness (more lumens per watt). But it costs 10 times as much.

Posted 1 year ago
Helpful (2)

Comments (2)

Helpful? (2)

Report

EnergyFred Answered:

The wattage would be identical but add the number of Lumens for each bulb to get the actual usable light output. Note that compact flourescents(CFL) and LED bulbs will produce more light than incandescents.