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Post by wvengineer on Feb 21, 2016 15:36:01 GMT
SO if I am looking for "daylight," I need to look for around 5000k.
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Post by the light works on Feb 21, 2016 15:48:40 GMT
SO if I am looking for "daylight," I need to look for around 5000k. yes. most off-the-shelf LEDs I buy are a bit whiter than the common CFL bulbs I buy, but if you want the blue-white look, you want to go with the higher numbers.
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Post by kharnynb on Feb 21, 2016 16:49:36 GMT
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Post by GTCGreg on Feb 21, 2016 20:45:00 GMT
GTCGreg, can you explain to me what the 3500K measures? I prefer the "daylight" bulbs over the more yellow ones. What would I be looking for? The guide kharnynb posted looks pretty accurate. At least on my computer monitor. 2700 to 3000 is about what an old incandescent bulb was. Most of the LED bulbs I've used for general replacement around the house are 3000K. The fluorescent tubes I've just installed in my office/shop are 3500. I'm really happy with the color of those. If I was going to use something in the garage or laundry room, I'd probably go with 4000K. I don't really care for anything much higher than that as the light is just to "stark white." for my liking. To my eyes, anything over 5000 starts to take on a bluish tinge.
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Post by silverdragon on Feb 24, 2016 6:50:28 GMT
One thing I have had problems with... Bathroom lights. We now have two. Mainly because during the day, and for things like shaving, you need a brighter light..... But Night time?... "AHHH Shazit BRIGHT LIGHT" You need something a little less bright in the middle of the night. Dont want Dimmers, because they are bad news, and the switches are outside the bathroom (Code requirements..)
I also have a bank of switches that can bring on the kitchen lights in stages... If I light all of the lights, its damn bright in there, and early morning just out of bed in the dark, it hurts your eyes?.. I now have one slightly less bright bulb over the kettle which give just enough to make a brew until my eyes get used to the light.
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Post by wvengineer on Feb 24, 2016 10:19:22 GMT
In the US, the common way of doing them is to have two light fixtures in a bathroom. The main room fixture is a normal single or double bulb setup to light the whole room. In addition to that you have a vanity light. That is a multi bulb (anywhere from 3 to 6 bulbs) fixture on its own switch located right by the mirror. The idea being that you can have the additional light for detailed work with the mirror (shaving, makeup, etc.) right where you need it and it is controlled independently.
How are UK bathroom setup?
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Post by kharnynb on Feb 24, 2016 14:42:11 GMT
at night i just sit down to pee, no light needed....
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Post by the light works on Feb 24, 2016 15:01:35 GMT
In the US, the common way of doing them is to have two light fixtures in a bathroom. The main room fixture is a normal single or double bulb setup to light the whole room. In addition to that you have a vanity light. That is a multi bulb (anywhere from 3 to 6 bulbs) fixture on its own switch located right by the mirror. The idea being that you can have the additional light for detailed work with the mirror (shaving, makeup, etc.) right where you need it and it is controlled independently. How are UK bathroom setup? UK code requires the light switches be outside the bathroom. the only power accessible inside is low voltage for the electric razor. we've discussed the apparent silliness of each other's requirements before. my first thought is to find a night light that will plug into the shaver outlet. I have a dimmer in my own bathroom. I have also done large numbers of installations that have a lighted vent fan; which include a nightlight option. the only issue I have had with my dimmer is that somehow the toggle for it came loose from the linkage. not sure how, it is the least used switch in the house. it only gets turned off once a week or so.
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Post by GTCGreg on Feb 24, 2016 19:35:42 GMT
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Post by silverdragon on Feb 25, 2016 7:09:15 GMT
at night i just sit down to pee, no light needed.... Until you need to wash hands.
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Post by c64 on Apr 17, 2016 10:37:33 GMT
You can't translate "Kelvin" to "daylight" at all. Kelvin is a temperature. When objects are hot, the wiggling of the atoms cause some kind of collisions in their molecular bonds. Energy is added to the orbiting Electrons of the atom. When the electrons gain too much energy, they would leave the orbit of the atomic core and atoms couldn't exist at all. To allow atoms to exist, the electrons can get rid of excess energy to dial in their perfect orbit. This is done in form of radiation. An electron can create a photon with its excess energy. Whenever an electron releases excess kinetic energy, a photon is created. There is no way to create "half photons" or fractions. An electron has to wait until it has enough excess kinetic energy to create a whole photon. It depends on the orbit of the electron when it has enough energy to be able to create a photon. The energy of a photon can vary. The more energy a photon has, the shorter its wavelength, the "more blue" the radiation. Inside a glowing object, the added energy is random but the hotter the object, the more likely an electron gains a lot of energy all at once. So the hotter the object, the more shorter ("bluer") wavelengths are present in the radiation. So lukewarm objects glow in infra-red only. If an object is hot enough, visible light can appear but the object still radiates mostly in infra-red. A glowing filament of a light bulb gives you this: The diagram is mirrored since it is for wavelengths. The longer wavelengths are on the right side, the shorter, more energy enriched ones on the left side. "Daylight" is very complicated. While the sun is extremely hot and cranks out all light frequencies with roughly the same average strength, the light is filtered through the atmosphere. Ozone filters the harmful UV-light but there are many more filters by Oxygen, Co₂, Nitrogen and water vapours. Then you get this: In the daylight spectrum, the left border is defined by Nitrogen and you can clearly see the water vapour gap in the red part, the reason why sunsets in the desert are much more red than over the sea. Over the sea, the sky turns red caused by water vapour scattering the light, in a desert the ground turns red while the sky stays blue since the red light isn't scattered. You can't describe this using Kelvin alone since Kelvin is just pushing the first diagram up and down through the X-axis, the more you push down (less Kelvin), the less blue you have left. Other forms of artificial light are worse. Gas-discharge systems are in fact monochromatic. Each gas has a characteristic light frequency it likes most. The valency electrons are exited by bombarding the atoms with electric energy and they tend to wait until they have a specific amount of energy before they create a photon. The favourite light frequency depends on the kind of gas. Neon for example is a low orange frequency. Neon signs rarely contain more than a trace of Neon, the bright signs use Argon and other gasses mixed to create the desired effect. Fluorescent tubes used to be filled with pure mercury vapour. Mercury has two favourite frequencies, one UV-near we can barely see as purple and "hard" UV we can't see at all. The "hard UV" then energizes the fluorescent coating which in turn glows in random frequencies which creates some kind of white but the shorter (bluer) wavelengths are dominant. So a classic fluorescent is the opposite of a light bulb. Modern fluorescents also contain Argon and other gasses to boost certain lower frequencies. This is an expensive so called "daylight" fluorescent tube. The peaks are (left to right) Mercury, Argon, Helium, Krypton and Neon. Compare this to real daylight from the diagram above and the highly expensive "daylight" lamps are not so daylight at all, are they? It is worse wit LEDs. One crystal can only emit one single frequency. Each n-th Electron jumping the bandgap of the crystal creates one photon leaving the LED. The current controls the amount of photons per second. The electron-volts of the bandgap control the frequency. There is no way to mix crystalls into each other so all LEDs are monochromatic. The so called "white LEDs" are in fact blue ones (or nowadays UV-LEDs) exiting a fluorescent coat. And since LEDs are stll nowhere near the hard UV of mercury, you get a lot of visible blue light so they use a yellow fluorescent which seems to create white out of blue and yellow. There is much turquoise missing and a lot of red!
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Post by c64 on Apr 17, 2016 11:06:13 GMT
Funny. We use pipes to connect our showers over here, not wires. Being a little more serious, those point of use instant shower heaters never really caught on over here. Over here, it depends. Originally boilers were used when you had the space and flash heaters when there was not enough room. A single family house usually had a gas boiler installed in the cellar, multi family houses a gas boiler or electric boiler in each flat to keep the bills separate. Tiny flats either had a flash heater or a so called "Therme" for the radiators and hot water. A "Therme" often was installed above the bath tub or if the (tiny) flat has none, right above the toilet. They heat your flat and give you are more or less random hot water temperature and the radiator temperatures vary a lot during long showers. Since small boilers in flats run out of hot water fast, flash heaters were preferred if the power (≤18kW) was available but they usually were "2-step" so you had to dial in your favourite temperature with the total flow. If you twist the "hot" tap, you get less water but it turns hotter since the temperature of the flash heater stays constant. So you need to regulate the temperature with the total flow usually using way more water than you need at constant electricity costs. So either you became sprinkled with little water at low power or hosed with lots of water at high power consumption. The alternative was a very expensive flash heater, I own an 18-step hydraulic controlled one. Here you can dial in the amount of water you like but the temperature may change 4°C out of a sudden when the heater "shifts gears" due to pressure changes in the pipes. Nowadays boilers are not really used any more. Heat exchangers fed by the central furnace or "stepless" electronic flash heaters are used. The only reason to use a boiler is when the wiring is too old and can't handle a flash heater and the flats have to have independent hot water for separating the bills.
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Post by the light works on Apr 17, 2016 23:47:54 GMT
here most flash heaters are gas fired, and have internal throttles to control the outlet temperature. if you exceed the capacity to throttle up the burner, it will restrict the water flow to compensate - which works okay since our shower valves are pressure balanced. - mainly to prevent scalds when someone flushes the toilet.
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Post by c64 on Apr 20, 2016 20:48:51 GMT
Gas powered flash heaters are very rare over here. They do exist but I have never seen one in RL. Heat exchangers tapping the heat from the central furnace became the norm almost 20 years ago. Flash heaters are usually used to make the tenant pay his own utility bill for hot water.
Flushing toilets are not a problem over here since the tanks of the toilets usually refill very slowly. If you have problems, just reduce the flow even more. Washing machines and dishwashers used to be a problem but modern ones also take in water more slowly since they don't need much water any more and need the extra time to make sure the soap dissolves correctly.
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Post by c64 on Apr 20, 2016 20:52:00 GMT
BTW. I just have bought a hot water dispenser. It is a 2.5kW miniature flash heater which slowly dispenses boiling water. It starts pouring water within 2 seconds and can stop any time instantly without any significant amounts of residual heat. Very energy efficient and a large cup of instant coffee within 12 seconds!
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Post by the light works on Apr 21, 2016 0:41:32 GMT
BTW. I just have bought a hot water dispenser. It is a 2.5kW miniature flash heater which slowly dispenses boiling water. It starts pouring water within 2 seconds and can stop any time instantly without any significant amounts of residual heat. Very energy efficient and a large cup of instant coffee within 12 seconds! we have those in a lot of higher end kitchens. ours are only about 1KW, though. Saturday the motor shorted on our reverse osmosis system at the car wash - they built the pump to fit an Italian motor - odds are the cheapest option will be to rewind the motor, as it is apparently proprietary to that pump, and is not sold here separately from the pump.
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Post by kharnynb on Apr 21, 2016 13:19:11 GMT
1 kW is bit tiny, that wouldn't even beat a decent electrical kettle.
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Post by the light works on Apr 21, 2016 13:28:14 GMT
1 kW is bit tiny, that wouldn't even beat a decent electrical kettle. but it doesn't require a special circuit and you don't have to rinse it. - and usually those have a small holding tank. (very well insulated, they usually don't even feel warm to the touch)
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Post by GTCGreg on Apr 21, 2016 23:28:06 GMT
BTW. I just have bought a hot water dispenser. It is a 2.5kW miniature flash heater which slowly dispenses boiling water. It starts pouring water within 2 seconds and can stop any time instantly without any significant amounts of residual heat. Very energy efficient and a large cup of instant coffee within 12 seconds! we have those in a lot of higher end kitchens. ours are only about 1KW, though. Saturday the motor shorted on our reverse osmosis system at the car wash - they built the pump to fit an Italian motor - odds are the cheapest option will be to rewind the motor, as it is apparently proprietary to that pump, and is not sold here separately from the pump. What size pump is it? May be cheaper to replace the whole unit with something more readily available.
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Post by the light works on Apr 22, 2016 0:07:45 GMT
we have those in a lot of higher end kitchens. ours are only about 1KW, though. Saturday the motor shorted on our reverse osmosis system at the car wash - they built the pump to fit an Italian motor - odds are the cheapest option will be to rewind the motor, as it is apparently proprietary to that pump, and is not sold here separately from the pump. What size pump is it? May be cheaper to replace the whole unit with something more readily available. what, you expect them to post specs on their proprietary equipment?
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