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Tech: light bulb wattage safety query ?
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Subject: Tech: light bulb wattage safety query ? From: GUEST,Bulbous Date: 12 Feb 09 - 12:25 PM Hi, In our victorian era front room with approx 9' high ceiling, we have an old ceiling light fitting that takes 3 traditional 40 watt 'candle' bulbs providing a not particularly over-bright illumination. I presume that is near [or perhaps above ?] the upper limit of its safety rating for overheating. Whatever, we have used it like this for nearly 10 years since moving in, and its not caught fire yet. My question is regarding replacement with new 'green' energy saving bulbs. 8 watt is supposedly the new equivalent luminosity of the old 40 watt bulbs, however, if I was to use 3 new 20 watt bulbs [which are supposd to be the same brightness as old 100 watts] would that be safe ?, ie. theoretically using half the power and generating half the heat of the old arangement of 3 x 40 watt bulbs whilst being at least twice as bright ????? P.s. I dont know how bright modern 40 watt energy saving bulbs are, [would they be the equivalent of something like old 200 watt bulbs ?] So, would 3 of those still be safe to use regarding potential overheating ? all informed advice welcome.
-Joe Offer, Forum Moderator- |
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Subject: RE: Tech: light bulb wattage safety query ? From: dick greenhaus Date: 12 Feb 09 - 12:47 PM power consumption (and, for all practical purposes, heat production) is measured in watts. Brightness, or the amount of light produced, is measured in lumens. Energy-saving bulbs prduce more lumens per watt than do the older incandescant bulbs. If you've been using 40 watt incandescents, it's just as safe to use 40 watt (or less( high energy bulbs. |
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Subject: RE: Tech: light bulb wattage safety query ? From: treewind Date: 12 Feb 09 - 12:54 PM Dick is exctly right. Replacing the 40 watt bulbs with 20 watt low energy lights as you suggest will win in four different areas: - more light - less power consumed - less heat generated - the bulbs will last longer Anahata |
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Subject: RE: Tech: light bulb wattage safety query ? From: Jack Campin Date: 12 Feb 09 - 12:54 PM You might want to think about weight. CFLs are much heavier than incandescents. What's holding them up? If it's just electric flex, you might need to change it or add a separate means of suspension. |
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Subject: RE: Tech: light bulb wattage safety query ? From: JohnInKansas Date: 12 Feb 09 - 02:01 PM The only problem I can see with your conversion is that, at least in the US, most "40 Watt candle" style bulbs have a "candelabra" base, which is a much smaller diameter socket than the "standard bulb" socket. The CFLs available with "light like 100W" are mostly with the same socket size as incandescent 100W bulbs, and I've had difficulty finding CFLs that will screw into the sockets on fixtures that use "candle" bulbs. I've changed two fixtures just to get rid of the "little bulb" sockets. If the fixture uses one of the two common (in the US) "mini base" bulbs, you may (or may not) have trouble finding CFL bulbs that will match the fixture. Since I made my conversions before most people were much aware of CFLs I haven't checked whether mini-base CFLs have become more available, and it may differ with where you are. An additional difficulty is that even when the socket is the standard size most CFLs have a larger diameter immediately adjacent to the socket. The old incandescents had a "neck" so that the larger diameter of the bulb was an inch or two away from the socket. The CFL larger diameter at the socket may not clear decorative globes and shades that surround the socket in a few cases. I have one fixture that will only take "60W equivalent" (13-1/2W) CFLs, and only those with a "smaller than some" base, because of a glass "tulip" that surrounds the bulb. I haven't had much trouble finding CFLs that will fit, but have to remember to look for the "small base" kind. In that particular fixture, not all currently available bulbs of the same power/light output rating will fit; but ones that do fit are fairly widely available - if I remember to check before I buy. When CFLs first appeared, many were labelled "base down use only." From experience I can say that if you used those "base up" they would still last longer than an incandescent, but not much longer. I believe that limitation has pretty much disappeared. With "modern" CFLs you shouldn't see that instruction; but if your fixture has "hang down" bulbs it wouldn't hurt to check the packaging before buying a bunch of spares. (There's usually a paper sticker label on the bulb base where the warning would appear if it's applicable. I wouldn't expect to see it on any currently available CFLs.) John |
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Subject: RE: Tech: light bulb wattage safety query ? From: bubblyrat Date: 12 Feb 09 - 02:15 PM If it was me,I would go out and buy- up as many 40 Watt "candle "bulbs as I could,and not bother about these ridiculous,heavy,ugly,politically-correct monstrosities that our "big brother " power-crazed government has foisted upon us (without any consultation,as usual ). I HATE them ( The new bulbs AND Brown's government). Tip----once they (old-style bulbs) become impossible to source commercially, try looking at car-boot sales and similar outlets."They " can't hang or imprison you for using them-----can they ?? |
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Subject: RE: Tech: light bulb wattage safety query ? From: Q (Frank Staplin) Date: 12 Feb 09 - 03:43 PM Broken CFL bulbs release mercury in excess of EPA standards. See second article linked below for precautions. The bulbs, when spent, should be properly recycled, but most end up in landfills, adding to environmental contamination. My fixtures are partly antique; some will not take the new bulbs. So far, there is no problem to getting the incandescents. Wiki article- Compact fluorescent A better article on dangers and proper disposal procedure here: energy saving bulbs |
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Subject: RE: Tech: light bulb wattage safety query ? From: GUEST,Auldtimer Date: 12 Feb 09 - 03:45 PM Change the lamps to 60w they will be fine. The extra current caused by the increasing total wattage from 120w to 180w will cause no overloading of your lightng circut and, providing you are not in the habbit of draping your socks, underwear or other combustable items over your light fittings, will present no overheating risks. |
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Subject: RE: Tech: light bulb wattage safety query ? From: Q (Frank Staplin) Date: 12 Feb 09 - 04:16 PM Modern ceiling fixtures come with safety recommendations re wattage. |
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Subject: RE: Tech: light bulb wattage safety query ? From: folk1e Date: 12 Feb 09 - 08:21 PM "Modern ceiling fixtures come with safety recommendations re wattage." ..... Yes but see Dick's post above! No light bulb is going to weigh so much the fitting will not hold them! Just be sure to check the fitting's type, S.E.S. (Small Edison Screw) is the most common by far! Also be aware the new lamps are larger than the old candle bulbs! They also light up slowly to full brilliance and can have some odd "coloring" to them if you buy cheap ones. |
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Subject: RE: Tech: light bulb wattage safety query ? From: Rowan Date: 12 Feb 09 - 08:38 PM Just be sure to check the fitting's type, S.E.S. (Small Edison Screw) is the most common by far! While fittings taking bulbs of SES and standard Edison screw bases are freely available in Oz, the standard sockets are "bayonet" fittings. Cheers, Rowan |
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Subject: RE: Tech: light bulb wattage safety query ? From: Q (Frank Staplin) Date: 12 Feb 09 - 09:14 PM I'm sure almost no one in Canada or U. S. knows what SES or Edison Screw is. All we have are standard incandescents and "energy smart" mercury types with a screw base about 1" in diameter for our 120v. current. Don't think I have seen bayonet fittings except in some specialized equipment; some automobile or equipment bulbs are insert and turn, whatever those are called. Of course there are some fancy lamps or Xmas strings with multiple sockets that take bulbs with smaller diameter bases, but I haven't seen new mercury fluorescents in those sizes in the supermarkets where we buy bulbs. |
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Subject: RE: Tech: light bulb wattage safety query ? From: robomatic Date: 12 Feb 09 - 09:23 PM 1) Check the fitting (the thing the bulbs plug into) for a max. wattage rating or for a make and part number. If you have that information or can look it up on the web thou shalt not exceed that wattage rating- Wattage determines the heat put out by the installation. If you are able to put in a more efficient lamp which puts out more lumens per watt, you are safe in using something that uses the same or fewer watts and puts out more light. 2) You may have additional options beyond CFLs (Compact Fluorescent Lamps). The market is beginning to see some LED lighting on the scene. I do not think LED lights introduce any mercury, however, similar to CFLs, they don't run straight off 120V AC, they need a power supply to provide the right driving DC voltage. These are sure to become more available and much cheaper in the near future. They should have very very long lifetimes (They are introducing LED STREET LAMPS to Anchorage). |
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Subject: RE: Tech: light bulb wattage safety query ? From: McGrath of Harlow Date: 13 Feb 09 - 08:21 PM Bayonet fittings for bulbs are still by far the most common in the UK. While were drifting around, has anyone found any viable version of these newer bulbs which can work with a dimmer switch? |
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Subject: RE: Tech: light bulb wattage safety query ? From: Q (Frank Staplin) Date: 13 Feb 09 - 08:55 PM GE makes CFL bulbs which work with a dimmer switch, but they are North American screw base. Look for GE CFL UK bulbs on the net- seems to me that if they make them with screw base, they would be able to do the same for other bases. |
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Subject: RE: Tech: light bulb wattage safety query ? From: Rowan Date: 13 Feb 09 - 11:18 PM The most common screw base in the US (from my observation) is known as the Edison Screw fitting; it is about 1" in diameter. The same type of base but only ~1/2" in diameter is known as the Small Edison Screw fitting. Cheers, Rowan |
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Subject: RE: Tech: light bulb wattage safety query ? From: JohnInKansas Date: 14 Feb 09 - 02:23 AM "Modern" light fixtures in the US a little more conservatively rated than most older ones, but in either case the maximum watts rating is just what won't set the fixture on fire, or in some cases won't ignite "flammable materials" within a specified short distance. In nearly all cases, if you use bulbs for which the fixture is rated you won't burn up. This does not mean, however, that even the rated bulbs won't eventually cause "undesired effects." In the US, plaster board construction has been common for a long time. A "surface mount fixture," and particularly one with a close-fitted globe, can heat the board where it's mounted to high enough temperatures to "cook the moisture out" of the plaster board. After a few years, or decades, you may find that what was originally "rocklike plaster" in the board is now "plaster powder" - and when you try to put up a more modern fixture, at best the screws won't hold, and at worst you end up with a big hole in the ceiling. The insulation on the wiring can also be embrittled by the heat so that it cracks and falls off when you try to connect the new fixture. Using incandescant bulbs a little larger than the rating on the fixture is not too likely to cause a fire, but it may greatly accelerate the aging of things nearby. When I needed a replacement because the bulb sockets had started to crack, I found that the "nearest equivalent" for a 40 year old surface mount fixture that was rated for three 60W bulbs now had only two 60W or, in another style, three 40W bulbs listed as acceptable. I went with a "hang down" style that put the bulbs about a foot below the ceiling, and instead of the 3 60W incandescant bulbs it was rated to use I use three 17W CFLs. And I used a 27" diameter "decorative fascia plate" to cover the hole in the ceiling that resulted when the "electrician's assistant" in the attic wiggled a wire with "coked" insulation in the connection box while the electrician was on the ladder down below with his nose in the box. I'm not sure which of them made the hole, but there was a whole lot of rapid motion on both sides of the ceiling for a few seconds. Then they replaced a couple of feet of wire. John |
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Subject: RE: Tech: light bulb wattage safety query ? From: Jim Carroll Date: 14 Feb 09 - 04:48 AM As an enthusiast for 'saving the planet' I welcome any effort to conserve energy - as an electrician with forty years experience I believe the shift to low-wattage is one of the most ill-thought-out ideas since the invasion of Iraq in order to find WMD. 1. Theoretically, watt-for-watt, the two types of lamp 'should' produce the amount of light claimed. Because of the present design of such lamps, less light-spread is produced requiring a larger wattage (thus reducing the claimed power saving). I am sure that new designs will hit the market eventually, but I am also sure that the price will rise accordingly. 2. The present L.W. lamps have a warm-up period which means that it is some time before they reach full light. This means that use of them is, at best, inconvenient and to the visually restricted, possibly hazardous - try walking into a half lit room full of furniture sometime. I am sure that new 'instant-light' designs will hit the market eventually, but I am also sure that the price will rise accordingly . 3. Householders using dimmer switches will have to replace those switches with ones designed to be used on low wattage, (more expensive of course), or abandon them altogether. 4. Some designs of light fitting will not physically accommodate the present size and shape of low wattage bulbs. I am sure that new designs will hit the market eventually, but I am also sure that the price will rise accordingly. 5. The present high price of L.W. light bulbs is reflected (to some degree) in their considerable life-expectancy. Over my years as an electrician I was aware that light bulb life-expectancy reduced considerably; I have always been of the opinion that was a deliberate act on the part of the manufacturers to weaken the filament of these in order to sell more light-bulbs. I have no doubt whatever that the same technique will be used in the manufacture of low-wattage bulbs. I think people should recognise the emerging pattern by now - more expensive, less efficient lighting. I live in rural Ireland where, over the last decade, it has become the fashion to use exterior lighting, either for effect or for security. The most common form of exterior lighting is halogen and virtually all fittings are supplied with 500 watt tubes on purchase, at least twice the required size. Were the government serious about 'saving the planet' they would ban any form of all-night exterior lighting used for effect and would insist that security lighting was controlled by a movement sensor. They would also restrict the (at present extremely wasteful) consumption size of extrerior fitigs. Personally, while I don't accept Bubblyrat's SUV mentality I will be following his suggestion and stocking up on full wattage bulbs until the powers-that-be get their act together. Jim Carroll |
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Subject: RE: Tech: light bulb wattage safety query ? From: Paul Burke Date: 14 Feb 09 - 07:21 AM Watts= heat produced (nad light oif course, but it's mostly heat). The fitting is rated for heat produced, so if it's rated for 3x40 watt bulbs, you can put 3x40watt ANYTHINGs into them safely. 20 watt compact fluorescents will be fine, for a (lot) extra expense you can get them with a similar profile to old candle bulbs now. As for the rest of the arguments, weight? If it's so fragile it won't be safe with anything in. Mercury? don't break them and dispose of them properly. The quantity is minute anyway. It seems some people are simply resistant to the idea of saving energy, and will grab hold of any objection, no matter how daft. I don't like the slow warmup of CFLs, but the best light of all is incandescent gas mantles, about as inefficient, wasteful of resources (rare earth salts in huge quantities, for an evanescent lifespan) and dangerous as lighting can get short of setting fire to your granny. |
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Subject: RE: Tech: light bulb wattage safety query ? From: Newport Boy Date: 14 Feb 09 - 08:00 AM While I think that some of Jim's points are worth considering, most of the things he suggests for the future are already here. Lamps2Udirect are a very good source in UK for all types of lamps, and the page linked gives a graphic view of most of the current range of CFLs. Lamps by Megaman are particularly good, albeit fairly expensive. Of the dozen or so that I have, only the little 'Pingpong' lamp has a significant startup time. I've not yet had to replace one in 7 years use. Phil |
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Subject: RE: Tech: light bulb wattage safety query ? From: artbrooks Date: 14 Feb 09 - 09:14 AM CFLs with candelabra bases are available (at least) up to 17 watt (60 watt equivalent)...I just put them into 2 new ceiling fans. Despite cautions about fan vibrations, I have used them for several years without problems. Almost all of the lights in my home are CFLs, and I've never noticed the "slow to reach full light" phenomenon. The only thing I'd caution is that they don't seem to work well in the cold, so might not be the best choice for outside lights. |
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Subject: RE: Tech: light bulb wattage safety query ? From: Jim Carroll Date: 14 Feb 09 - 10:32 AM "Lamps by Megaman are particularly good, albeit fairly expensive." My point exactly - I believe most of the reservations have been, or will be ironed out in the near future, but I also believe that the emphasis will shift from ecology to profiteering unless there are ground-rules from the very beginning. Already 'saving the planet' has become a cynical profit-making exercise elsewhere, as has 'fair trade' purchasing - there is no reason to believe that this will not be exactly the same. Jim Carroll |
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Subject: RE: Tech: light bulb wattage safety query ? From: Rowan Date: 14 Feb 09 - 11:24 PM 'saving the planet' has become a cynical profit-making exercise described here (in Oz) as "greenwashing". Cheers, Rowan |
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Subject: RE: Tech: light bulb wattage safety query ? From: Keith A of Hertford Date: 15 Feb 09 - 07:55 AM They save much less energy than the simple difference between their consumption and that of an incandescent equivalent because, if the room is being heated as well as lit, the thermostat will compensate and replace every watt of heat saved. Also, far more energy is used in their manufacture. |
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Subject: RE: Tech: light bulb wattage safety query ? From: Mr Red Date: 16 Feb 09 - 05:57 AM 3 x 20 watt energy-saving bulbs is safer than the 40 watt tungsten ones. The reduction in heat will be compensated by the central heating thermostat (insignificant anyway) but more to the point the heat will not stay 9 feet up and do nothing for your feet. Turning even efl bulbs switched off & on too often can reduce their life and given the warm-up time you will get better light after a few minutes. If you really want to save electricity & money you need the light source nearer to whatever you want to look at - and use less bulbs. eg a table lamp. Mr Red C.Eng M.I.E.E. |
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Subject: RE: Tech: light bulb wattage safety query ? From: GUEST,Jim Martin Date: 16 Feb 09 - 06:15 AM I agree with Jim Carroll, since I have lived in Ireland, I have been appalled by the pretentiousness of permanently switched-on exterior lighting (the 'look at my house, it's bigger & better than yours so there - boo sucks!' syndrome), especially in rural areas. A leftover of the now suffocated 'celtic tiger'! The lighting police should come round! |
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Subject: RE: Tech: light bulb wattage safety query ? From: artbrooks Date: 16 Feb 09 - 09:53 AM Reducing the heat produced by lighting can be a serious issue in those parts of the world where you spend as much time cooling a house as you do heating it. [...wonder if I'll need a sweater today?...] |
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Subject: RE: Tech: light bulb wattage safety query ? From: JHW Date: 16 Feb 09 - 11:06 AM Its time that light fitting manufacturers gave max ratings for low energy bulbs as well as the tungsten ones. An email reqd to the office of the Energy Regulator? |
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Subject: RE: Tech: light bulb wattage safety query ? From: folk1e Date: 16 Feb 09 - 05:47 PM If you are worried about all of the 500w floodlights you could always use High Pressure Sodium Vapor lamps 70 (yes Seventy) Watts is brighter than a 500w floodlight and is a better light too! |
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Subject: RE: Tech: light bulb wattage safety query ? From: Sawzaw Date: 16 Feb 09 - 06:13 PM You can put 60, 100 even 150 watt equivalent Compact Fluorescent bulbs in to replace a 40 watt incandescent bulb without overheating the fixture. 40 watt CFs use .075 amps or 9 watts 60 watters use .12 amps or 14watts 75 watters use .16 amps or 19 watts 100 watters use .19 amps or 22 watts 150 watters use .35 amps or 42 watts |
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Subject: RE: Tech: light bulb wattage safety query ? From: robomatic Date: 16 Feb 09 - 06:55 PM All but that last Sawzaw, 42 watts is over 40 and you leave it long enough, you will get what the electrical field folk call by the technical term: "crispy critters". |
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Subject: RE: Tech: light bulb wattage safety query ? From: Jim Carroll Date: 16 Feb 09 - 07:02 PM "If you are worried about all of the 500w floodlights....." I'm not particularly worried; I don't illuminate my house all night and the one halogen light I do have (sensor controlled, has the minimum sized tube). I am just struck by a government who will happily introduce a law making my lighting inefficient and costly, yet ignore one of the great power consumers - uncontrolled vanity lighting. All Fluorescent bulbs are undimmable and produce a cold, harsh, and to my mind, flat, characterless light, leaving the impression of an income tax office or an unemployment exchange. They can also exacerbate existing health problems; a friend is epileptic and one of the triggers is fluorescent lighting. Jim Carroll |
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Subject: RE: Tech: light bulb wattage safety query ? From: artbrooks Date: 16 Feb 09 - 07:20 PM The good news is...there are dimmable CFLs. The bad news is that they cost over $100 each. There are also "daylight" and "soft light" ones for people who can't take that harsh fluorescent glare...the prices are about the same. |
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Subject: RE: Tech: light bulb wattage safety query ? From: Rowan Date: 16 Feb 09 - 09:28 PM There are also "daylight" and "soft light" ones When I last looked closely at the printed matter on the packet accompanying one each of these I noticed a disparity in the output; output=lumens, here. I can't now remember which was which, though. Cheers, Rowan |
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Subject: RE: Tech: light bulb wattage safety query ? From: Stilly River Sage Date: 16 Feb 09 - 10:43 PM I'll skip past the various formulas and make note that while the LEDs cost more right now, they don't give off heat, they don't burn out, and there are some absolutely beautiful lamps made from them. I have several around the house that are enough to navigate by at night. Some are rechargeable (with built-in batteries) and others have adapters. For a fixture on the ceiling it would take a lot of LED bulbs to amount to anything, which might weigh more than you like. Why not skip the ceiling fixture and go with lamps around the room from wall plugs, and make some of them LEDs and the energy efficient fluorescent or very-efficient-for-the-wattage halogens? SRS |
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Subject: RE: Tech: light bulb wattage safety query ? From: Newport Boy Date: 17 Feb 09 - 06:25 AM artbrooks The good news is...there are dimmable CFLs. The bad news is that they cost over $100 each. They shouldn't cost that. There are about 8 different models in UK and price is about £10 to £12. Phil |
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Subject: RE: Tech: light bulb wattage safety query ? From: artbrooks Date: 17 Feb 09 - 07:00 AM For dimmable ones, Phil? They are well over $100US in our local hardware chain (Home Depot), according to their catalog. Nondimmables run anywhere from $5 to $15, but the electric company offers a substantial rebate. |
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Subject: RE: Tech: light bulb wattage safety query ? From: Newport Boy Date: 17 Feb 09 - 07:20 AM Yes, Art. Check out this page and click through to the details and prices. I couldn't find a similar product in USA. Phil |
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Subject: RE: Tech: light bulb wattage safety query ? From: SINSULL Date: 17 Feb 09 - 01:22 PM Two people died of smoke inhalation over the weekend here in Maine. Someone had thrown a pile of dirty laundry onto an electrical strip. It overheated. In addition, someone had removed all the batteries from the smoke detectors. Check yours, people. M |
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Subject: RE: Tech: light bulb wattage safety query ? From: artbrooks Date: 17 Feb 09 - 05:06 PM Interesting...thanks, Phil. |
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Subject: RE: Tech: light bulb wattage safety query ? From: robomatic Date: 17 Feb 09 - 08:38 PM Art: Costco had some dimmable CFL's when I was walking through this weekend, but I didn't stop to read the fine print. LEDs will be getting brighter and cheaper. The sporting goods stores (REI for us Americans) stock them for camper's headlamps. Costco sells them inexpensively as nightlights. They are showing up as dash lights and rear light / turn indicator lights on vehicles. And as I mentioned above they are being tried out as street lights in my own humble town. |
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Subject: RE: Tech: light bulb wattage safety query ? From: Bonzo3legs Date: 18 Feb 09 - 05:33 PM Until some lunatic with a clip board and a badge appears at my front door, I shall continue to use my stock of 100watt bayonet fitting bulbs as long as I see fit.These new bulbs should be measured in bollocks...as they are a load of...... |
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Subject: RE: Tech: light bulb wattage safety query ? From: Sawzaw Date: 18 Feb 09 - 09:39 PM "All but that last Sawzaw, 42 watts is over 40 and you leave it long enough, you will get what the electrical field folk call by the technical term: "crispy critters". I see your point but the CFs put out more light and less heat because they are more efficient. They convert mote of the electricity to light and less into heat. Therefore a 150 watt equivalent CF does not get as hot as a 40W incandescent bulb. At least I am pretty sure of it. I know that when I unscrew a 40 Incandescent while it is lit, it is so damned hot I have to use a towel. But with the CFs I can use ny bare hands. You could test this yourself just using your hands. I even have some 200 watters that I can unscrew with my bare hands. |
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Subject: RE: Tech: light bulb wattage safety query ? From: Sawzaw Date: 18 Feb 09 - 10:37 PM "All Fluorescent bulbs are undimmable and produce a cold, harsh, and to my mind, flat, characterless light, " Some of the CFs are dimmable. You have to seek out the warm white tubes that actually enhance the colors in a room. It depends on th K or Kelvin rating of the tube, the color temperature. Warm white or Soft white 3000 K or less White or Bright White 3500 K Cool white 4000 K Daylight 5000 K or higher The lower the K of the tube the yellower or even pinker the light and the better it shows off colors. The higher the K the bluer or colder the light and the drabber the colors are "rendered". I get my CFs at Home Depot in $7 packs of 4 in a mostly green blister pack which makes the colors nice. They are called N:VISION soft white. I have had a few out of dozens of these go out in a week but the rest have been working for years. Some of them "sing" and if they are in like a desk lamp they bother your ears. In that case you just swap it with another one that is quiet. CFs are 17 to 21% efficient at converting electric power to radiant power as opposed to 5-10% for incandescent bulbs. |
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Subject: RE: Tech: light bulb wattage safety query ? From: s&r Date: 19 Feb 09 - 07:45 AM Fluorescent lamps have a different spectrum of emitted wavelengths, often with sharp peaks in the green region. daylight fluorescent lamps are not like daylight - try taking pictures with each. Colour matching incandescent lamps are available for artists and craft workers - these have a blue coating to remove the excess yellow of incandescent lamps. Stu |
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Subject: RE: Tech: light bulb wattage safety query ? From: robomatic Date: 19 Feb 09 - 11:55 AM Sawzaw you are confusing wattage with light output. This is important! A 40 watt maximum rated fixture is just that. A 40 watt incandescent lamp is using the same amount of current as a 40 watt CFL lamp. The CFL may be putting out a heck of a lot more lumens for those watts, but the energy use is the same. In the context of this thread, the idea is to replace 40 Watt incandescent lamps with much lower wattage CFLs that put out more light. The package on the cover of the CFL may claim "puts out as much light as" a given wattage, but it is the ACTUAL wattage of the CFL you've got to pay attention to. Every incandescent lamp and every CFL lamp puts out waste heat. Every fixture and mount is designed to dissipate heat up to a certain amount. No doubt there are safety factors involved, but one should abide by the rating on the fixture. If you install a lamp which puts out more heat than can be dissipated, even by a single watt, the temperature inside the fixture and its mount goes UP until a new balance is achieved. That higher temperature means shortened life expectancy of the fixture, the wire insulation, other nearby items such as insulation and paneling, and increases the chance of fire. One other reason to respect the fixture rating is that CFLs require a power converter to take mains voltage and start and power fluorescent lamps, and the converter has its own efficiency and its own heat output which may or may not be included in the wattage rating on the box cover. You still get to put in a more efficient lamp and get more light output per watt. Just don't take it beyond sensible limits. |
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Subject: RE: Tech: light bulb wattage safety query ? From: dick greenhaus Date: 19 Feb 09 - 11:45 PM An often-overlooked point--If you heat your home with electric resistance heating, you might as well leave in the incandescents. A 100 watt bulb produces (for all practical purposes) 100 watts of heat, and you get the light as an extra. |
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Subject: RE: Tech: light bulb wattage safety query ? From: The Fooles Troupe Date: 20 Feb 09 - 08:49 AM QUOTE The lower the K of the tube the yellower or even pinker the light and the better it shows off colors. The higher the K the bluer or colder the light and the drabber the colors are "rendered". UNQUOTE ARGH! Bollocks! "Daylight" (ie for practical purposes 6000K+) bulbs are used for 'colour matching' as lower K temp light distort the red end of the spectrum.... aaaaggghhhh... |
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Subject: RE: Tech: light bulb wattage safety query ? From: robomatic Date: 20 Feb 09 - 11:55 AM Dick- Not true when the bulbs are in the ceiling. Not true when the bulb is in your fridge. Not true when you're trying to COOL your house! Irrelevant when the bulb is outside! |
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Subject: RE: Tech: light bulb wattage safety query ? From: Musket Date: 20 Feb 09 - 12:09 PM Just to add and reiterate from some of the above; the wattage is the power consumed as in you pay for (in KWHrs, one unit is 1 KW for 1 hour, 2KW for 30 mins etc.) the bulbs when they say equivalent, means light intensity equivalent, (measured in Lumens but you will not see a Lumens rating on most bulbs.) So, if you had 3 x 40W = 120W before, and you now have 3 x 20W = 60W, your electricity bill will be half as much EXCEPT energy saving bulbs strike up similar to a fluorescent strip, and use more power during start up than during use, so this is only true if you don't keep turning them on and off. Regarding the safety you mention, the new bulbs are far more efficient so more of that power is used for producing light, hence less loss through heat, hence running cooler and safer. Cable warmth is related to the power. the more current (measured in Amps) the warmer the cables. Current (I) = Power (P)/voltage (V) So, the voltage remaining the same, the lower the power (in Watts) the lower the current (in Amps) and the cooler the cables. |
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Subject: RE: Tech: light bulb wattage safety query ? From: Sawzaw Date: 20 Feb 09 - 06:26 PM "ARGH! Bollocks!" Read about it at Wikipedia. When I say the more the lower K tubes show off the colors I mean the colors are brighter. There are lavender fluorescent tubes for grow lights and aquariums that make colors look like they glow. I am very familiar with the CRI, the color rendering index of different fluorescent lamps if you want to get technical. I remember when an architect specified "Crtiti-Color" fluorescent tubes for the lighted sneeze guards in a cafeteria counter that I designed. But hey, buy whatever you want. I am only saying what I prefer to buy that to me, keeps the colors from looking drab like a "cold, harsh, and to my mind, flat, characterless light" does and CFs put out more light per watt than incandescent bulbs. As I have explained. A CF lamp that draws 42 watts will not get as hot as a 40 watt incandescent lamp. Why? because less of that 42 watts will be converted to heat. If the incandescent bulb is 10% efficient at converting watts into light then 90% or 36 watts gets converted into heat. If a CF lamp that draws 42 watts is 20% efficient, 80% or 33.6 watts gets converted into heat. I am using conservative percentages. I can also state that I can unscrew a CF lamp that draws 42W with my bare hands but I cannot unscrew an incandescent lamp that draws 40W with my bare hands after they have been on for a while. I bought 60W equivalent soft white CFs at Home Depot today in 4 packs for $2.85 which is $.72 each. |
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Subject: RE: Tech: light bulb wattage safety query ? From: The Fooles Troupe Date: 20 Feb 09 - 07:45 PM With incandescents, there is simple maths related to how high the glowing filament temp is and how the bell curve shifts to the UV end of the CONTINUOUS spectrum away from the infra-red end (all incandescents give off large quantities of IR - especially those 12V jobs) which is why they developed dichroic lamps... simply the higher the K rating the more similar to natural sunlight and thus the better for 'normal colour matching purposes' they are. Lamps that emit light by fluorescence are a totally different kettle of worms... :-) you can fiddle with the phosphors to your hearts content to get whatever mix of individual spectrum lines you want, but you will NEVER get the exact same sort of spectrum as an incandescent source, like the sun... but you CAN FAKE it... hey, TV. Films, and LCD & Plasma monitors do it all the time... :-) But they DO emit less IR (detected and assimilated as heat)... :-0 |
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Subject: RE: Tech: light bulb wattage safety query ? From: robomatic Date: 20 Feb 09 - 09:09 PM Sawzaw: We don't have many 42 W CFL's here, I suppose it's advertized as putting out the equivalent light as a 150W or 200W incandescent? Nevertheless IF the fixture has a wattage rating, you are not safe in exceeding it, regardless of the technology. As for hot to the touch, you may be overlooking that the surface area of an incandescent lamp, being spherical, is less than that of the CFL twisted cylinder, hence the heat output is distributed over a greater surface, hence the temperature over parts of the surface may be lower. What is more there is a power supply between the fitting and the lamp, it is not 100% efficient so it will produce heat as well. Now you may be correct that due to its efficiency there is less total heat output by the CFL, but an additional consideration to the fixture is the current which is fed to the lamp, and the current going to 40 watt incandescent at 120V will be 0.33 Amps, and the current going to a 42 watt CFL at 120V will be higher. A third of an amp might not be much, but it is what the fixture is designed for. |
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Subject: RE: Tech: light bulb wattage safety query ? From: Sawzaw Date: 20 Feb 09 - 11:59 PM I believe the wattage limit is the limit of the amount of heat that the lamp holder and fixture as a whole can take, based on Incandescent bulbs. Especially if it is an old fixture. The 2 watts difference in current is .0167 amps. The ampacity of #18 wire which is the smallest wire I know of in a fixture is 7 amps which which is 840 watts or 20 of those 42 watt loads. I do go 5% over the limit marked on the fixture myself with CFs but if you are uncomfortable with that, don't do it. I am only telling you what I do and why. It may be a moot point because the 150 watt CFs might not physically fit. 40 watt equivalent CFs use .075 amps or 9 watts 60 watters use .12 amps or 14 watts 75 watters use .16 amps or 19 watts 100 watters use .19 amps or 22 watts 150 watters use .35 amps or 42 watts Our bathroom vanities have a long fixture over the mirror with 12 of those dressing room type clear globe incandescent lamps in it. I think they were 40 watts. I replaced them with 60 watt equivalent CFs and it was so damned bright in there I had to replace them with 40 watt equivalent CFs. At first my wife said they were ugly but she got used to them. |
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Subject: RE: Tech: light bulb wattage safety query ? From: GUEST,Baggy Trousers Date: 21 Feb 09 - 10:16 AM "At first my wife said they were ugly but she got used to them." my wife was exactly the same when we first got married; now 30 years later she's quite fond of my old 'bulbs'........ |
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Subject: RE: Tech: light bulb wattage safety query ? From: folk1e Date: 21 Feb 09 - 05:50 PM The designers of a fitting will work out their design using standard "building blocks" eg wire thickness = #18! This means that they will arrive at a fitting that can take a fixed load ..... they then use the next lower size of bulb! Eg .... Fitting electrical capacity = 7.5A = just under 2KW(Two Thousand Watts) ...or 1KW in 120v system! Fitting max thermal dissipation = 50W ....which is the real lamp max wattage! Lamp rating = 40W As you can see the key factor is the thermal dissipation of the fitting not it's electrical rating! If you use a lamp that gives less heat you can go to a higher wattage! It's all a bit pedantic though, isn't it? I have for the last 4 years had a 4 lamp fitting in my kitchen that is running on 240v LED's (10 LED's per lamp). The fitting has been up for 6 years with halogen lamps to start with (but I got sick of changing them).... the LED's were a straight swap, and I haven't looked back since! |
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Subject: RE: Tech: light bulb wattage safety query ? From: dick greenhaus Date: 22 Feb 09 - 11:59 AM Just to point out that there are two factors determining maximum permissible wattage: the wiring (as folkle described), and the ability of the fixture (housing, shade etc.) to withstand heat. In either case, actual wattage is the only safety consideration. |
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Subject: RE: Tech: light bulb wattage safety query ? From: s&r Date: 22 Feb 09 - 12:57 PM And of course the ability of the fixture to dissipate the heat generated - e.g. if a fitting is within a ceiling space insulated with rockwool then the temperature of the fitting will be higher than if it were in free air, and th plastics will degrade Stu |
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Subject: RE: Tech: light bulb wattage safety query ? From: Bill D Date: 22 Feb 09 - 07:59 PM Here is a .PDF with an explanation of CFLs and why some packages will say 'dimmable', but have fine print saying not to use with dimmers. Basically, proper operation requires a newer type of solid-state dimmer. You can't just replace an incandescent with a CFL in older fixtures. |
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Subject: RE: Tech: light bulb wattage safety query ? From: Bill D Date: 22 Feb 09 - 08:40 PM And here is a web page which also explains it pretty clearly. |
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Subject: RE: Tech: light bulb wattage safety query ? From: bubblyrat Date: 23 Feb 09 - 07:01 PM O Yea !! O Yea !! Todaye, in Ye Towne of Reading in Ye Countye of Barkshire in Olde Englande, hath I discovered Ye Shoppe called "Poundland", in Ye Street called Friar,wherein canst be Pur-chase-ed Ye Olde-Tipe Bayonnette-fitting,Incandesc-aye-ent Lyte-bulb,in great Store, and verily in Divers shaypes and Wattages,for ye Tryfling summe of but one Pownd of the Relm per Pakkage of up to Syxe Itemms ! So Fukk ye Moddern Poovey,Faerie-lyke overe-Wayte and most Cumbersumme Eyetims-!! I doo Noe whereat I shall Partake my Custtom for sutch Requysites in ye Cumming Munths and Yeres! |
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Subject: RE: Tech: light bulb wattage safety query ? From: robomatic Date: 23 Feb 09 - 08:18 PM Yonne Lighte-Yemitting Dioddes shalle takke yonne Olde Type Bayonette Incandiescentte eventuellement. ying-tong-iddle-eye-po! Rob yclept Omatic |
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Subject: RE: Tech: light bulb wattage safety query ? From: GUEST,Jon Date: 23 May 09 - 08:05 AM Re the dimmer switch: We are using X10 home automation here. There is no (at least not requiring a neutral wire) alternative switch I know of. Minimum wattage is 60W and I can not use any type of florescent. Hope there is a new switch at some point which I can replace as and when able but for now, it's try to keep a good stock of GLS bulbs in. A thought on the lower light output of CFL. Will this encourage the use of more track/spot lighting? If had say a 100W GLS in a central fitting lit the room adequately but found my 20W CFL didn't do as well, I guess I might be able to add a few GU10 halogens to help out but I'm not convinced I need wind up with an energy saving. |
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Subject: RE: Tech: light bulb wattage safety query ? From: pdq Date: 23 May 09 - 11:46 AM Just for fun, ask a few people you know if incandescent light bulbs have been banned in the United States. I have asked many people and nobody has given the correct answer yet. Here are the facts: Congress bans incandescent bulbs Massive energy bill phases out Edison's invention by 2014 Posted: December 19, 2007 7:18 pm Eastern © 2009 WorldNetDaily.com In addition to raising auto fuel efficiency standards 40 percent, an energy bill passed by Congress yesterday bans the incandescent light bulb by 2014. President Bush signed the 822-page measure into law today after it was sent up Pennsylvania Avenue in a Toyota Prius hybrid vehicle. The House passed the bill by a 314-100 vote after approval by the Senate last week. Rep. John D. Dingell, D-Mich., chairman of the House Energy and Commerce Committee, said the legislation will boost the energy efficiency of "almost every significant product and tool and appliance that we use, from light bulbs to light trucks." The phase-out of incandescent light is to begin with the 100-watt bulb in 2012 and end in 2014 with the 40-watt. All light bulbs must use 25 percent to 30 percent less 2014. By 2020, bulbs must be 70 percent more efficient than they are today. Australia was the first country to announce an outright ban by 2010. Critics of Thomas Edison's invention argue it uses more energy to produce light than the compact fluorescent, or CFL, bulb. While standard light bulbs cost about 50 cents, the spiral CFL sells for about $3. Advocates argue, however, the CFL lasts five years longer and uses about 75 percent less energy. But as WND reported, the presence of small amounts of highly toxic mercury in CFLs poses problems for consumers when breakage occurs and for disposal when bulbs eventually burn out. The potential environmental hazard created by the mass introduction of billions of CFLs with few disposal sites and a public unfamiliar with the risks is great. Consumers generally are unaware of the risks of CFLs, and recycling experts say the solutions are at least five years away. The Department of Energy, nevertheless, is encouraging citizens to take a pledge to replace at least one incandescent bulb with a CFL. |
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Subject: RE: Tech: light bulb wattage safety query ? From: Q (Frank Staplin) Date: 23 May 09 - 06:23 PM Canada has a similar 2012 turn-off. So lay in a supply. |
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Subject: RE: Tech: light bulb wattage safety query ? From: Bill D Date: 23 May 09 - 06:32 PM Well... I just saw dimmable CFLs in my grocery store the other day...and they didn't say I needed a special fixture. I am at about 80% CFLs now, and will gradually buy the others as I need them. (I just realized I have at least 2 CFLs that have been in place for over 6-7 years now. I KNOW I have saved what I paid for them several times...) It's an idea whose time has come..... |
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Subject: RE: Tech: light bulb wattage safety query ? From: Q (Frank Staplin) Date: 25 May 09 - 01:18 PM My bathroom light fixtures are recessed an confined (also ceiling fixtures and spotlights in parts of living area). Recommendations are against putting the CFL's in such fixtures because heat build-up causes the bulbs to fail. I tried it in one, and the CFL (Energy Star labeled) failed after 5 months. At Canadian prices for these bulbs, this is costly, and the U. S. packages give only an Ohio address for warranty replacement. Instructions say only not to use near wireless devices, receivers, computers and the like, and cautions about mercury disposal, but nothing recommended here, so they go into the garbage. Looks like I will have to replace the fixtures by 2012, or keep a supply of the old bulbs (last about one year). Suggestions? |
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Subject: RE: Tech: light bulb wattage safety query ? From: robomatic Date: 25 May 09 - 03:38 PM At worst, Q, you will have to pay for new fixtures which will work with CFLs. But in your place I would wait. Technology is not standing still. LEDs are the next wave, and CFLs will prolly get phased out in their own stead, after a much briefer period as home lighting mainstay. In other words, screw-in CFLs are more of an interim technology (much like CDs are for music). I'm sure the mercury issue will weigh against them in the near future. LEDs are being used in some streets in Anchorage as streetlamps already. They have nowhere to go but down in price. While LEDs are far more efficient in light output per electric power consumption, they still put out heat at what's called the 'junction', the very tiny bits that connect the LED (which is a semiconductor) to its power source. Therefore, the care and feeding of LED as lamps will still require proper mounting. So don't panic, stay tuned. |
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Subject: RE: Tech: light bulb wattage safety query ? From: Jim Carroll Date: 26 May 09 - 08:38 AM Quickie Further to my suggestions on the limitations of low wattage bulbs - during work on digitising analogue recordings, have recently found that they can produce interference via computer. Jim Carroll |
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Subject: RE: Tech: light bulb wattage safety query ? From: GUEST,tommigirl Date: 08 Jun 09 - 10:24 PM I was wondering if changing the bulb in my flush to the ceiling "2-bulb light fixture, from 40watts to a 90 watt light bulb would be a major safety concern ???? many Thanks For any advice I can get! |
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Subject: RE: Tech: light bulb wattage safety query ? From: Rowan Date: 08 Jun 09 - 10:42 PM Quite a few of earlier posts (above) would inform you that it would be most unwise to exceed the wattage/safety rating of the fixture; two 40W bulbs add up to less than one 90W bulb so you'd have to change the entire fixture. Cheers, Rowan |
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Subject: RE: Tech: light bulb wattage safety query ? From: Q (Frank Staplin) Date: 08 Jun 09 - 11:30 PM Yep, possible hazard. We have a ceiling fixture in our front hall that takes low wattage bulbs, and the light is insufficient. The new bulbs will not fit in it. The fixture is attractive, and we hate shopping around for a new one, so we keep putting off replacing it. |
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Subject: RE: Tech: light bulb wattage safety query ? From: artbrooks Date: 09 Jun 09 - 08:33 AM I found some mini-twisted fluorescents (13w each)that are smaller than "traditional" incandescents. 2 of these would give you the equivalent of 120w. They may also come in higher wattage, but I wasn't looking for more than these. |
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Subject: RE: Tech: light bulb wattage safety query ? From: GUEST,Track Lighting NOOB Date: 11 Jun 09 - 12:57 AM I have track lighting. On one strip I have 3 lights. On the track it says 120W max. Now is that 120W for each light, or 120W between the 3 lights i.e. each light can have a 40W thanks |
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Subject: RE: Tech: light bulb wattage safety query ? From: artbrooks Date: 11 Jun 09 - 08:24 AM Probably 40x3, but look inside one of the three fixtures to see if they have individual ratings as well. If the max per fixture is 40, than you can use a 23w (100w equivalent) compact fluorescent, assuming that it uses "traditional" type bulbs at all.. |
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Subject: RE: Tech: light bulb wattage safety query ? From: GUEST,friend of yours Date: 16 Jun 09 - 08:39 PM i like chicken aswell as cars. lights are gay but not headlights |
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Subject: RE: Tech: light bulb wattage safety query ? From: The Fooles Troupe Date: 17 Jun 09 - 12:16 AM BTW, I've seen CFLs that have an equivalent rating of 230 Watts (Aust 240V ES) in Hardware stores |
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