T5 vs. Metal Halide: Finding The Energy Savings
Compiled by FacilitiesNet Staff
Metal halide lamps are a fixture in industrial and warehouse space. But today, a number of lighting systems offer alternatives that can slash energy costs. T5 lighting systems are one example.
Delivering high-lumen output, new T5 HO (high output) and T5 VHO (very high output) fluorescent lamps provide an energy-efficient option for a variety of industrial and high-bay applications previously dominated by metal halide technology.
The smaller diameter of T5 lamps contributes to overall luminaire efficiency. Here's how T5 vs. metal halide lamps break down: Compared to 400-watt universally mounted metal halide lamps, T5 VHO lamps can save up to 40 system watts per fixture and deliver as much as 75 percent longer lamp life. Maintenance and relamping costs can be reduced as well, experts say.
What’s more, T5 systems can bring other bottom-line benefits. A 400-w standard MH system mounted on 20-foot centers meets the ASHRAE 90.1-2001 standard of 1.2 w/sf, calculating to 1.15 w/sf. Replacement with four-lamp T5 HO fixtures comes out to 0.59 w/sf, a reduction large enough to qualify for tax deductions under the Energy Policy Act of 2005 (EPAct).
Amalgam technology helps these systems deliver greater light output over a wider temperature range. The systems are optimal for applications such as unconditioned warehouses, shop floors, factories and big box retailers.
T5 systems provide white light without color shift, as well as the benefit of controllability through dimmers or occupancy sensors, according to lighting experts. What's more, the applications for T5 HO and T5 VHO lamps are rapidly expanding.
T5 systems give industrial users the best of both worlds — the long life and energy-efficient benefits that fluorescent technology has to offer with no sacrifice in light output.
Sources:
A New Era for Lighting by John L. Fetters
Lamps & Ballasts: Move from Good to Better
baytran7
Yellow Tang Join Date: Sep 2004
Posts: 288
T5 vs Metal Halide debate answered
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When you have a fixture that claims X watts, you have to also consider that (X= Input power). The true power you are using due to inefficiencies such as (Y=magnetic/copper loss) is equal to X+Y. For Example:
Metal Halides:
Claim:
250w puts out 16500 lumens
Actual:
295w total due to inefficiencies (Y) puts out 16500 lumens
T5s
Claim:
54w puts out 5000 lumens
Actual:
62w total due to inefficiencies (Y) puts out 5000 lumens
What does this mean?
(2) 250 watt Metal Halides
you burn 590 watts to get 33000 Lumens with Metal Halides
(6) 54 watt T5s
you burn 372 watts to get 30000 lumens with T5s
Now if you love the Heat, High energy bills and the Shimmer Effect of Halides then the Metal Halide if the fixture for you.
If you want the most bang for the buck then T5s are the fixture for you.
I won't get into power compacts or T8s because those are not worth the research. Plus they are not enviroment friendly due to the higher mercury levels.
All this Data is gathered from the Sylvania + GE 2006 catalogs so you can find out for your own which you want better. I did this because I got tired of people saying "You can only keep this animal with Metal Halides + Chiller." Wrong..... It's not about the Watts per gallon.
There is also things that contribute to lumen gains/loss, here they are in order of most impact
reflector design
Height it is from top of tank
Y factor
Operating temp of lamp
age of lamp