What's Cheaper To Maintain...400W Metal Halide Or T5?

Posted by Jimmy Hovey on Wed, May 23, 2012 @ 11:05 AM

Do You Know How Much It Costs400-w-metal-halide-or-t5 To Maintain Your 400W Metal Halide or T5 Fixture?

How Much Does It Cost To Re-Lamp (Change out the bulbs...)?

Not how much it costs when you flip the switch.....I'm talking about what it to maintain the light fixture once it has been installed.

Lets Look At An Example

Let's say we have a medium sized manufacturing facility.  In the warehouse work area, there are 60 - 400 watt metal halide fixtures.  The lights are lit up about 4015 hours on an annual basis.

Determine Your Rated Lamp Life:

400 watt metal halide lamp life = 18-20,000 hrs.

Fluorescent T5 lamp life = 35,000 hrs.

(Side Note....)I need to mention right now that the 400 watt metal halide light output diminishes significantly with use. In fact, a 400 watt metal halide bulb will be 70% less bright in 3 years as the day you installed it. 

Sort of like a new car, drive it off the lot new and when you bring it back in 3 years, it is only worth 30%.  The light from a 400 watt metal halide will never be as bright as the day you put a new bulb in. 

At 8-9,000 hours, or roughly 50% of the rated life of the bulb, you are only getting about 60% of the light output when new.

Because of the reduction in lumen output, you realistically should replace the lamps every 2-3 years.....even though the lamp still works.  While it still works, in reality, the lamp is not as bright as it was on day one.  This is called lumen depreciation.

One important fact to consider: Even when the 400 watt metal halide is giving you 50% of the light due to lumen depreciation, you are still paying the same for the electricity powering the fixture. 

In other words your paying for full light output and in return getting 50%. If your going to pay for 400 watts of light at least my scenario will give you that most of the time.

What Is The Difference In Maintenance Savings?

Lamp Life Expectancy For Our Example:

So with 4015 hrs of annual usage our fluorescent T5 lamps will go roughly 8 years before needing to be changed.

(35,000 hour lamp life/4,015 hours annual use = 8.7 years life expectancy)

Our 400 watt metal halide will last roughly 5 years

(20,000 hour lamp life/4,015 hours annual use = 4.98 years life expectancy)

But wait?

Isn't the light output diminished 60% at 9,000 hrs? Yep...sure is. So at 12,000 hrs I'm only getting 50% of the light I should?

Assuming the quality of light is important to you, If we replace the lamps every 12,000 hrs, thats every 3 years.

Let's Look At The Cost Of Group Re-Lamping

Group re-lamping is doing a complete replacement of bulbs, or in this case the 60 all at once rather than just replacing a few here and there. 

Cost of 400w Lamp and Ballast:

400 watt metal halide lamp = $17.00

400 watt metal halide ballast kit = $80.00

So every 3 years we will spend $1,020 on lamps.

(60 replacement lamps X $17 per light = $1020 for replacement bulbs) I didn't forget the ballast.......

What About The Ballast and Capacitor?

Ballasts usually last a long time.....the capacitors however seem to fail at around 3 to 3 1/2 yrs.

Yes you can replace just the capacitor, and we have before.....only to get called back 2 weeks later because the ballast died.

Funny thing is, customers never remember you saved them money by replacing the capacitor. 

What they remember is 2 weeks ago you said you fixed it and now your back because it's broke again.  We don't like unhappy customers, so as a rule we change out the ballast and capacitor at the same time. 

(60 fixtures X $80 per ballast kit = $4800 for ballast kit)

So the combined cost of the lamps and ballast kits equal:

($1020 for lamps + $4800 for ballast kits = $5,820.00 every 3-3 1/2 yrs)

How Many Times Do You Have To Re-Lamp 400w Metal Halide Before Re-lamping T5?

The fluorescent T5 fixture will last almost 9 years at this usage.

You will go through lamps and ballasts 3 times before we need to think about touching the T5 fixture.

(9 years before maintenance fluorescent T5 / 3 years before maintenance of 400 watt metal halide = 3 times, you will have to maintain the 400 watt metal halide 3 times)

($5,820 materials X 3 years = $17,460.00 in materials)

What About Labor and Equipment?

I purposely did not include labor, this is just materials.  Business owners usually have someone to do the maintenance.  There is a cost to that.  We did the calculations separate, so you could make the choice.  

Some places have there own lifts and electricians, others hire it out.

For our example, I will use a very conservative cost for labor, $4,000.

We need to figure a lift for 1 week, $675

($4000 labor cost + $675 lift rental = $4865 for labor and equipment)

Assuming you want to maintain your lighting levels, you will have to do this 3 times with the 400 watt metal halide vs the fluorescent t5. 

($4865 x 3 times you will need to maintain the fixtures= $14,025 labor/equipment)

Lots Of Numbers, How Do We Bring It All Together?

Well it took us awhile to get here, let's add up all the numbers to see how much it will cost you to maintain the 400 watt metal halide vs the fluorescent t5:

($17,460 in materials + $14,025 labor/equipment = $31,485 to maintain 60 fixtures over a 9 year period)

Cost Per Fixture

So if you maintain your 400 watt metal halide correctly, over a 9-10 year period, operating the lights at 4,015 hours per year here is what it will cost you per fixture:

Just Material;

($17,460 materials / 60 fixtures = $291 in materials to maintain the lights)

 or materials and labor;

($31,485 materials,labor/equipment / 60 fixtures = $524.75 each to maintain 60 400 watt metal halide)

Remember, $524.75 is the cost to MAINTAIN the fixture; this has nothing to do with the initial cost (if you are installing them new) or the cost of electricity to power these things. 

There Is A Real Cost To Lighting Maintenance

The numbers above are not exact, but the you get the idea.  There is a cost of maintaining 400 watt metal halides.  Few businesses actually take the time to figure it out. 

Most businesses don't change the lamps when they need to, but if you are comparing the light output between the 2 fixtures, you have to factor in the change out every 3 years. 

Look Deeper, There Is A Reason Why 400 Watt Metal Halide Is Cheaper

Calculate all of the costs when making a lighting decision for your business. 

Architects, Engineers and Designers are STILL specifying the 400 watt metal halide fixture, so you need all the facts before you make the decision. 

Afterall, you will be the one paying for maintaining the fixtures, not the Architect, Engineers or Designers. 

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Topics: 400w metal halide fixtures, 400w mh, 400w metal halide, metal halide or T5, 400 watt metal halide, metal halide 400w