Hi everyone. In my basement, I have a drop ceiling. In the spot where I have the 2 clear tiles for lighting, instead of fluorescent lights, the original homeowner pout in light housing for normal screw in light bulbs that are nailed to the floor joists. The maximum watt light bulb I can put in these housing is 150 watt. So in my basement now I have 2x150 watt light bulb illuminating my area. My question is this, what will give me an overall brighter basement, 2x150 watt light bulbs, or if I buy two fluorescent worklights, each one holding 2x40 watt fluorescent tubes for a total of 4x40 watts (I believe the brightest fluorescent tubes are only 40 watts?). I know simple math seems to say the 300 watt total from the light bulbs would do it, but I would say every 2 months or so one of the 150 watters blows out (we use our basement a lot, so the lights can be on for hours at a time). Cost of these bulbs isn't a major issue however, the lighting is more so. Any advice is appreciated.
Incandescent bulbs are rated in both watts and lumens. While a higher watt rating does make for more light, it is really a measure of power consumption. Lumens in the light output. Compare the 150 watts with the tubes. A regular 150 watt bulb puts out about.2100 lumens
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Watt, 10,000 Hour Rated Life, 2650 Initial Lumens, Replaces 150 Watt Soft-White Incandescent, Estimated 70% Energy Cost Savings vs. Incandescent, Screw-in Base & Self-Ballasted Excellent CRI, Warm 2700K color
One 40W fluorescent tube is going to be equivalent to something around a 150W filament lamp. You can easily lose half the light in the fitting with filament or fluorescent lamps, so a comparison of the raw filament lamp verses raw fluorescent tube light output won't necessarily give you the whole storey -- it will also depend on the type and positioning of the light fitting.
Fluorescent lights are much more efficient, and emit a *lot* more light per watt consumed, than incandescents. You'll probably get about twice as much light from 160 watts of fluorescent tubes as from two 150-watt incandescent bulbs.
Compare the rated lumens output on the packages, not the wattages, when comparing fluorescents to incandescents - that's a measure of the actual light output.
Bottom line: incandescent bulbs emit most of the energy they consume as heat, while fluorescents emit most of it as light. If your objective is to heat your basement, use incandescents. If you want to illuminate it, use fluorescents.
And if you prefer the yellow, "warm" glow of incandescent bulbs to the stark white "cool" light of fluorescent tubes... get compact-fluorescent bulbs that screw into a standard incandescent socket. Best of both worlds: warm glow, and energy efficiency.
Incandesant bulbs output apx 17-19 Lpw, lumen per watt. Flourescent screw in bulbs apx 50-70 lpw. Tube flourescent 60-110 Lpw, or 4-6 times the output of what you have. Actualy incandesants are heaters that output 90% of their energy as heat and only 10% as light. Using a screw in Cfl will up efficiency apx 4x, using tube T8 can up it 6 times. But a recesed fixture will still loose you 50% of light output.
I will guess an exposed fixture of T8, electronic ballast of one 30 watt tube could equal those 2-150 watt bulbs you have, quite a savings and it will last 5x longer. You can also run dimmers on certain electronic ballasts for real control . Go to an electric supply store for real info, but converting to T-8 electronic ballast, exposed fixture is the way to go for light output and power savings.
Or buy 2700K fluorescent tubes (at least, they're available in the UK if you look for them), and they would blend well if you also have any other filament lamps around. 3500K should be fine too if the lighting level is high and you don't need to blend with other filamane lamps. Anything above this can start looking cold unless the lighting level is very high.
If you want dimmability, you could stick with incandescent. It is cheap and easy to dim. By the way, if you do dim incandescents, even a little, they will live way longer. But, as other people have said, fluorescent lamps will put out much more light (lumens) per Watt. With an acrylic lens recessed fluorescent fixture, you will probably get about half of the lumens out of the fixture. I don't know what type of fixture your incandescent lamp is in. If it's a bare bulb hanging down into your space, you will be getting a lot of its lumens.
Over 30 years ago, in the ceiling of our warehouse, I installed
2 incandescent sockets side-by-side and wired them in series. I inserted 60 watt bulbs which gave about the light output I wanted for a night light. They burn rather dim, and the original bulbs are still going, day and night. Makes for a dependable night light.
So, a 60W lamp running at half voltage is about 21W power consumption and about 10% of full light output, i.e. equivalent to a 6W lamp. A 4W fluorescent tube which is going to be roughly similar light output to the two underrun lamps.
So, I guess you've been wasting (2 x 21) - 4 = 38W for 30 years in lamp inefficiency due to underrunning inappropriate lamps, which comes to a total of 10 megawatt-hours of wasted energy. That would have cost me £1000 (1800$US) at todays prices. You would have needed around 10 new tubes over that period, but those would have cost you less than 2% of the money wasted.
You can select different incandescent and fluorescent bulbs with different characteristics, so the answer is all over the place and always right. How much light you get from a bulb depends on where you measure the light, spatially and spectrally. E.g, a 100 watt par 40 spot will have more and less light than a 100 watt par 40 flood and it can have more light at some illuminated areas than do some 100 watt fluorescents. There are standards as to the shape and distance used to get that bulb's lumen/light reading on the package, but most bulbs don't track you around the room, so you have to make a few decisions.
For the home, it is a bit simpler than choosing light commercially- many books on the subject leave your head hurting over candela, lumens, lumens per, temperature K, etc. - but the basics still apply:
Primary decision is what do you want to do in the space? Usually, and obviously, it involves seeing detail (like sewing), or not seeing so the imagination can fill in gaps (like in a club). Hence there are dimmers in multi-use spaces on some overhead fixtures, and there is incandescent spot lighting on tables and wall decorations mixed with fixed fluorescent overhead area lighting.
Some guidelines - - Seeing well requires 1) contrast and 2) proper kind of lumens on the surface and 3) lack of conflicting contrast. In other words, you see better with more light and less shadow, and it also means that the less contrast you have (e.g., sewing dark on dark), the more lumens you need. (The rule of thumb for commercial space is that a
10% decrease in contrast in the work requires a 100% increase in the lumens on the surface.)
- often, where you put the light has more effect than how much. Spots vs. floods, a 60 watt par 30 spot on a table vs. a 40 watt tube in an overhead fixture, etc. and placing sources so there is little shadow and yet a light source isn't in your eyes, either.
- bulb efficiency is measured in lumens per watt (almost always measured at a voltage), and overall efficiency is measured including the cost of changing the bulb - which is why a 130 volt bulb giving poor lumens per watt (vs. the same 120 volt high lumen-per-watt bulb) is sometimes more cost-efficient when the bulb is hard to get at.
Consider using several kinds of lighting to supplement the likely ceiling fluorescents (avoid shop lights, imho), and consider adding low voltage halogen spot lighting to the fluorescents, which often doesn't require the same level of electrical work that a 120 volt installation does
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