Can you add lumens

However, if you place the two lamps apart from each other their overlapping light will eliminate shadows that you will perceive as more light or at least a better lit space. IMHO more lights of lower lumens will light a space better than a single lamp of the total of all their lumens.

Ask the theater people. Do 2 bulbs with lumens provide the same illumination as one with lumens? I agree with our local Retired Master Electrician's answer but if you want to put on your physicist's hat, the answer is no. Lumens are a measure of luminous flux not of illuminance which is closest to what you probably mean by illumination. Two lumen bulbs might produce very different values of Illuminance as one lumen bulb.

Two lumen bulbs produce the same luminous flux as one lumen bulb. If you were specifying some office space and needed to meet some regulations, you'd need to understand these distinctions. If you are a home-owner choosing between light fittings or bulbs made 8, miles away, it is likely that this sort of distinction is unimportant to you.

You can buy light-meters that measure illuminance. I suppose an old-school photographer's light-meter makes a reasonable substitute. The simple answer is yes. Of course there are several other things you need to consider.

One brought up by Ed Beal. Lumens are simply visible light output at the bulb. If they're reasonably aimable, then yes. Two 2-tube fluorescent fixtures next to each other will be almost exactly as bright as one 4-tube.

If they're not aimable, then each light is putting the other light in shadow, so you're losing some to that. To calculate the illumination of a room you need to take into account the room shape, fixture position and height, light source angle, CRI, light temperature, wall coverings, etc..

Sign up to join this community. Thread starter doobnVA Start date Aug 1, Good morning So, this whole thing about lumens really confuses the crap out of me and I'm hoping someone can either explain or point me to some reading material that breaks it down in terms I can understand. Keep in mind that it's been more than 10 years since I've set foot in a math or science class Now, as I understand it, lumens don't really mean anything when it comes to how plants use light.

Lumens are a measurement of light that's visible to humans, right? And somehow you have to convert that to something called PAR what the crap does that stand for? Basically, PAR is how much light the plants can "see" and use, right? I've also heard that lumens don't add up? So if you're using 26W CFL lumens it doesn't matter how many you use, you're still only getting lumens? It makes sense to me that a bulb I'm using on one plant at the end of the row isn't going to benefit a plant at the other end of the row I'm so confused.

Anyone want to shed some wisdom on this subject for me? They add regardless of what people say, a handful of cfls will have more lumens concentrated in one spot than just 1 cfl alone. Thanks, I guess it's the weekend and nobody wants to think too hard. The voice in the back of my head tells me the same thing, and I've seen some CFL grows using lots of low watt bulbs to surround the plant with light and they seem to be pretty successful.

Hopefully someone will come along soon and make sense of this. Plants "see" light differently than human beings do. As a result, lumens, lux or footcandles should not be used to measure light for plant growth since they are measures used for human visibility. In addition to quantity of light, considerations of quality are important, since plants use energy in different parts of the spectrum for critical processes. TLeom Active Member.

I think you are swapping lumens for kelvins. You cna add up the lumens but not the kelvins. They do and they don't Light diminishes further it travels. Adding lights only gives you full power further away. If you guess actually want to get down to how plants use light you must look into something called umol. It is a special formula that you can never expect to understand that takes most aspects of a plant to figure it maximum amount of usable light. There is much research that needs to be done on weed before we know what its umol is.

If you want to learn about how umol works then look up how much light is required for lettuce to grow. I warn you, its like the red of blue pill in the matrix. Itll fuck yo mind up. Lumens don't add. The reason the t-5 setups your looking at say 20, lumens at 5, lumens per bulb is because the 5, lumens is spread out over a larger area.

So when buying light bulbs, think lumens, not watts. The brightness, or lumen levels, of the lights in your home may vary widely, so here's a rule of thumb:. To help consumers, the Federal Trade Commission requires manufacturers to include a product label for light bulbs on the package. It helps people buy the lightbulbs that are right for them.

Like the helpful nutrition label on food products, the Lighting Facts label helps consumers understand what they are really purchasing. The label includes the following information:.