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I currently have 51 T12 48" 2 lamp shop lights in my shop.
I am looking into changing to some more energy efficient lighting.
I read that T8 & T5 lights are more energy efficient than the T12s. I am confused on how they are more energy efficient when they use the same wattage bulbs.
I was taught that wattage is energy used, so how does the same wattage use less energy?

The current shop lights are plugged into outlets in the ceiling. I am also toying with the idea of getting plug in light socket adapters & LED flood light bulbs to plug into the outlets to see how they would light the shop. What I like about this idea is that it would cost less for the conversion & some of the LED bulbs have the color of incandescent bulbs.

The ceiling in most of the shop is 9' 6". another part has a cathedral ceiling that starts at 9' 6" & goes up to 12'.

I did a calculation of energy use if I was to go with all LED bulbs. That would cut my electric bill by about $87 a month.

I have no idea how to figure what the energy cost difference would be to convert to T8 or T5 lights.
 

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I currently have 51 T12 48" 2 lamp shop lights in my shop.
I am looking into changing to some more energy efficient lighting.
I read that T8 & T5 lights are more energy efficient than the T12s. I am confused on how they are more energy efficient when they use the same wattage bulbs.
I was taught that wattage is energy used, so how does the same wattage use less energy?

The current shop lights are plugged into outlets in the ceiling. I am also toying with the idea of getting plug in light socket adapters & LED flood light bulbs to plug into the outlets to see how they would light the shop. What I like about this idea is that it would cost less for the conversion & some of the LED bulbs have the color of incandescent bulbs.

The ceiling in most of the shop is 9' 6". another part has a cathedral ceiling that starts at 9' 6" & goes up to 12'.

I did a calculation of energy use if I was to go with all LED bulbs. That would cut my electric bill by about $87 a month.

I have no idea how to figure what the energy cost difference would be to convert to T8 or T5 lights.
Sounds like you know how to figure cost but are missing a couple of figures. I believe you are missing the ballast factor /drain/wattage to fire off those 32 watt bulbs. If you can find that difference in power usage , you should be able to figure the rest. I'd do it but I am currently really sick and having a hard time concentrating..
 

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Also missing here is the brightness factor. A 32-watt bulb is indeed a 32-watt bulb, but each puts out a different amount of light as measured in lumens. A bulb that puts out 1000 lumens at 32-watts is more efficient that a bulb that puts out 600 lumens at 32-watts.

Light efficiency is measured as "Lumens per Watt" or "LPW"

T12=78 LPW
T8=90 LPW
T5=99 LPW


To put that is layman's terms - for the same 32-watts consumed, you get a lot more light out of a T8 or T5 bulb than you do from a T12. In theory, if the lighting with a 32-watt T12 is adequate, then you could drop down to a 26 or 28-watt T8 and get the same amount of light.
 

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I agree with above. It is also fairly easy to switch from T12 to T8. All you need it to swap out the ballasts. I converted some old 4' 4 lamp fixtures that my old job was going to scrap.


Sent from my iPhone using Tapatalk
 

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At work, we made a switch quite a few years back from T12's and mercury vapor to T5's. Now we're moving to LED lighting, they seem a little harsh at first, but the workers are getting used to them. I don't know the savings from each move, but the LED fixtures are pricey.

We're moving to more and more LED lighting at home. For my garage, and basement, I started to move from T12's to T5's but it seems that The T5 bulbs were quite a bit more expensive that the T12's. And it seems that the T5's had a shorter life. May just be my imagination.

I'm saving my pennies for LED lighting, it seems to be the wave of the future.

Just my 2 cents.
 

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I'm saving my pennies for LED lighting, it seems to be the wave of the future.

Just my 2 cents.
I agree. LED, everything else is old inefficient technology. It is a bit pricey now, but that will change too.
 

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LED is the way to go! Focus on lights that get used the most, and convert them to LED first. We just built a new home and put LED everywhere except closets and a couple spots that rarely get used. I can already see it paying dividends!
 

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I didn't go for "energy efficient", I went for Lumen's. When I need to see, I don't care if its costing me a few more pennies and hour-I need to see! :laugh:

T5's in the basement workshop, and T5HO's in the garage and pole barn.
 

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I have T8's in my garage and I'm about to swap them out for LEDs. Not so much concerned with energy use but The T8s still take a few minutes to warm up in the unheated garage. It's just a little frustrating when I go out there for something fairly quick and have to wait for them to warm up to get full light output.
 

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If you stay with fluorescent , go with 5000K tubes weather you go with T8 or T5 fixtures. You can reduce your total amount of fixtures and still increase your candlepower.
 

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I currently have 51 T12 48" 2 lamp shop lights in my shop.

I am looking into changing to some more energy efficient lighting.
I read that T8 & T5 lights are more energy efficient than the T12s. I am confused on how they are more energy efficient when they use the same wattage bulbs.
I was taught that wattage is energy used, so how does the same wattage use less energy?

The current shop lights are plugged into outlets in the ceiling. I am also toying with the idea of getting plug in light socket adapters & LED flood light bulbs to plug into the outlets to see how they would light the shop. What I like about this idea is that it would cost less for the conversion & some of the LED bulbs have the color of incandescent bulbs.

The ceiling in most of the shop is 9' 6". another part has a cathedral ceiling that starts at 9' 6" & goes up to 12'.

I did a calculation of energy use if I was to go with all LED bulbs. That would cut my electric bill by about $87 a month.

I have no idea how to figure what the energy cost difference would be to convert to T8 or T5 lights.
Oh, where to start...

1. 40watt is a "nominal" wattage, not actual VA.

This means multiply ballast factor for light output and wattage consumed. .88 or 1.0 is typical for electronic T8. Old magnetic T12 ballasts are most likely 1.0. Ballasts or fixtures can be specified ordered many ways, ie program start, instant start, dimmable. I need to know what you're planning on using to give you an estimate on energy savings or use. Also how long are the lights used in a typical day, week, or month?

51 x 2 = 102 lamps
102 x 40w = 4080 nominal watts
4080w x 1.3eff= 5304VA real power.

Which is 44.2 Amps at 120V. That is what a ammeter should read if you totaled up your lighting with it all on, and all fixtures working.

If this is a residential meter, they don't consider VA. Only watts. So a commercial meter will charge you 5.3kw per hour, but a residential will charge you the 4.1kw per hour.

Commercial charges for demand, so if you lower the lighting you most likely lower your total demand. This charge is most beneficial to commercial customers to save money and power.

Residential has no demand charge, just a straight Kw rate. But a higher kw rate than commercial. But consider taxes on your kw rate which in my area for residential puts it at around 15¢ per kwh.

There is also inefficiencies of ballast loss which on old magnetic ballasts can be around 30%.

2. Enter in CRI and K temperature to get adjusted lumens. Higher CRI gives colors a truer match to sunlight. T12 is in the 60's. t8 and t5 is in the mid 70s to mid 80's. Some specialty LED and flourescents are in low 90's. incandescent and halogen/xenon are 100.
K(elvins) is the shade from red to white(and what some percieve as blue because of low CRI). Rough examples:

Good automotive detail and body shops use a 5000K. Retail is 4100k. Offices 3500k. Incandescent 2500k or so.

3. Is the Shop heated or not? T8 and t5 do well to 32°F. They are rated much lower than that, and will self heat, in a few minutes, somewhat but lumen output will suffer as the temperature greatly drops. HO is "high output" which means higher nominal wattages and thus higher heat output, with higher ballast factor possible.

4. How often do you turn the lights on and off? This affects the lamp and ballast life immensely.

5. Not all LEDs are equal. Lamps can be directional. Diffusers can be directional. Up light/down light and room color and texture all play into the final calculated average footcandle achieved.

Confused?

Lets start with:

How long are the lights on and what do you use the shop for?

What is your budget?

Do you want a specific look (aesthetically) or function over form?

Maybe I can help!:thumbup1gif:
 

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I am interested in this thread as I am not liking the T12 fluorescent lights in my unheated 3 car garage. When it is below freezing, only 2 of the 6 8ft bulbs will come on. 30 to 40 degrees maybe another one or two will come on.

I have been looking at the T8 LED replacement bulbs. The ballast must be removed to make them work, but that is no problem. Still unsure about whether the end fittings have to be replaced.

Anyone else went this way???


Dave
 

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LED is where it is at if you can afford it. Not only will they save power they produce more light. The last time I priced stripped lighting LED was about 5 times more expensive than T5, $400 a strip vs $80
 

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I too think LED is the way to go.

Sent from my SM-T900 using Tapatalk
 

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Discussion Starter #18
Oh, where to start...

1. 40watt is a "nominal" wattage, not actual VA.

This means multiply ballast factor for light output and wattage consumed. .88 or 1.0 is typical for electronic T8. Old magnetic T12 ballasts are most likely 1.0. Ballasts or fixtures can be specified ordered many ways, ie program start, instant start, dimmable. I need to know what you're planning on using to give you an estimate on energy savings or use. Also how long are the lights used in a typical day, week, or month?

51 x 2 = 102 lamps
102 x 40w = 4080 nominal watts
4080w x 1.3eff= 5304VA real power.

Which is 44.2 Amps at 120V. That is what a ammeter should read if you totaled up your lighting with it all on, and all fixtures working.

If this is a residential meter, they don't consider VA. Only watts. So a commercial meter will charge you 5.3kw per hour, but a residential will charge you the 4.1kw per hour.

Commercial charges for demand, so if you lower the lighting you most likely lower your total demand. This charge is most beneficial to commercial customers to save money and power.

Residential has no demand charge, just a straight Kw rate. But a higher kw rate than commercial. But consider taxes on your kw rate which in my area for residential puts it at around 15¢ per kwh.

There is also inefficiencies of ballast loss which on old magnetic ballasts can be around 30%.

2. Enter in CRI and K temperature to get adjusted lumens. Higher CRI gives colors a truer match to sunlight. T12 is in the 60's. t8 and t5 is in the mid 70s to mid 80's. Some specialty LED and flourescents are in low 90's. incandescent and halogen/xenon are 100.
K(elvins) is the shade from red to white(and what some percieve as blue because of low CRI). Rough examples:

Good automotive detail and body shops use a 5000K. Retail is 4100k. Offices 3500k. Incandescent 2500k or so.

3. Is the Shop heated or not? T8 and t5 do well to 32°F. They are rated much lower than that, and will self heat, in a few minutes, somewhat but lumen output will suffer as the temperature greatly drops. HO is "high output" which means higher nominal wattages and thus higher heat output, with higher ballast factor possible.

4. How often do you turn the lights on and off? This affects the lamp and ballast life immensely.

5. Not all LEDs are equal. Lamps can be directional. Diffusers can be directional. Up light/down light and room color and texture all play into the final calculated average footcandle achieved.

Confused?

Lets start with:

How long are the lights on and what do you use the shop for?

What is your budget?

Do you want a specific look (aesthetically) or function over form?

Maybe I can help!:thumbup1gif:

That is a lot of information. Thank you.

The shop is behind my home. The lighting is on the house meter. The power costs a lot less here through the house meter.

I have a commercial service for the machines.

I have never understood how the kVar & KW Demand comes into play on figuring the cost of electric. My bill lists numbers for those, other than that the bill is identical to my house bill.

The shop is heated.

In the winter, the lights are on a average of about 8 hours a day 6 days a week. In the summer they are maybe on an average of 3 hours a day.

The budget is small.

As far as looks, I now have plug in 2 lamp shop lights.

I like the color of incandescent bulbs. I have gotten used to the white light, but it makes it more difficult to match colors of wood & finishes. Also clients have problems seeing colors in the different lights of their home & my shop.
 

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I have never understood how the kVar & KW Demand comes into play on figuring the cost of electric. My bill lists numbers for those, other than that the bill is identical to my house bill.
For many commercial services, your aren't penalized for a poor power factor or peak demands, but it's still listed on the bill.
Most of the time, even if a utility does penalize you for power factor, it's after a certain threshold.
A previous poster suggested that you are billed for VA's and not true power on commercial services, but that is not true, you are always billed for true power, but may be surcharged for a poor power factor.
Inductive loads are typically the cause of a poor power factor. What happens is the current sine wave and the voltage sine wave begin to shift out of phase from one another. This means that loads do not use or dissipate the power efficiently. It's a real PITA for the whole grid.
 

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For many commercial services, your aren't penalized for a poor power factor or peak demands, but it's still listed on the bill.
Most of the time, even if a utility does penalize you for power factor, it's after a certain threshold.
A previous poster suggested that you are billed for VA's and not true power on commercial services, but that is not true, you are always billed for true power, but may be surcharged for a poor power factor.
Inductive loads are typically the cause of a poor power factor. What happens is the current sine wave and the voltage sine wave begin to shift out of phase from one another. This means that loads do not use or dissipate the power efficiently. It's a real PITA for the whole grid.
Correct.

VA is what the electrical system sees. That is what the utility company provides after reactance loss of efficiency. That is the Kvar charge.

Kvar is one factor of what you'll be saving $ on if you are billed commercially. T12, t8, and led all create Kvar.

I'm trying to keep it simple, :tongue: but my explanation fell short

Watts = real power
VA = apparent power x power factor = watts

Thanks Arlen!
 
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