Empowering you to understand your world

Recessed Lighting Uses Far More Energy Than You Think!

Recessed lighting uses the same light bulbs, but in neat, recessed fixtures that many people love. I have observed lighting setups in countless office buildings, stores, and houses, and saw that most of them used recessed lighting. I found them to be attractive, but, there is a major problem with them: Their efficiency.

recessed lighting
Recessed Lightning – Image obtained with thanks from mccun934 on Flickr.

Recessed lighting normally involves using several light fixtures for each 100-300 square foot room. Each of the incandescent light bulbs is upwards of 25 watts (usually over 40,  often 60, which is like a 15 watt fluorescent bulb), and at least a few are on at any given moment.

Assuming a common scheme in which 6 of these 60 watt bulbs is utilized. The power consumption amounts to a staggering 360 watts. Lights are usually on for 6 hours per day in sunny climates, so that translates to a cumulative power consumption of 2,160 Wh (2.16 kWh) per day, which amounts to almost 65 kWh per month, which exceeds the power consumption of a modern 25 cubic foot refrigerator, which is about 45 kWh.

65 kWh will cost you $7.15 USD at an electricity cost of $0.11 USD per kWh, which is average in the U.S., or $28 USD ($2,800 JMD) at an electricity cost of $0.43 USD per KWh, which is sometimes the case in Jamaica.

Since this is 65 kWh per room, that means that the total house-wide power consumption would trounce that of all household refrigerators and some air conditioners.

Recessed Lighting With Fluorescent Light Bulbs

If all of the 6 incandescent bulbs above were 15 watt fluorescent ones, they would amount to 90 watts, which is still far more expensive and energy-intensive than the 15 watt option proposed below.

I actually achieve better brightness in 100-200 square foot rooms with a single 15 watt fluorescent light bulb, and the same brightness with a 60 watt incandescent light bulb, using the following fixture:

Non-recessed Light Receptable - Image obtained with thanks from dpstyles on Flickr: http://www.flickr.com/photos/dpstyles/
Non-recessed Light Receptable – Image obtained with thanks from dpstyles on Flickr.

The single 15 watt fluorescent light bulb consumes: 15 watts x 6 hours = (90 Wh per day). That is 2,700 Wh per month (2.7 kWh), which costs $0.29 USD at an average electricity cost of $0.11 per kWh, or $1.16 USD ($116 JMD) at a cost of $0.43 USD per kWh (Jamaica).

Switching to this saves $6.86 per month in the U.S (it would save $2,684 JMD monthly in Jamaica), and the replacement of one recessed lighting fixture with the type above will pay for itself in one month (provided that you stop using the rest of the recessed lighting fixtures).

All you need is one bulb and a non-recessed lightning fixture per room!

Leave a Reply

Subscribe to our newsletter
Get notified when new content is published