T5 or T8

[ptonsparky]

I am doing some comparisons of fixtures and lamps t8 vs t5 for a couple projets. I find depending on mounting height, etc, that T8s may give a more even coverage for less initial cost. Given that a customer could use t5s in one location and t8's in another would you install the different types or go with the t5s?

 

[bob]

Did you use the same fixture and lense with you test?

 

[ptonsparky]

Used the Vision software and compared three brands as suggested by suppliers with t8 & t5 versions of each. One brand had a marked difference in distribution. Almost like they are intended for aisle lighting in a warehouse and not for gyms. That sales person had no idea what an ies file was. The other two brands are very close in results. T8s are a bit older, are they already outdated?

 

[jeremysterling]

IMO, different tube diameters throughout the project is OK. Install the best or next-best fixture for the application.

When replacement lamps are ordered, they will invariably be the wrong color, length, wattage and/or diameter. Therefore, trying to homogenize lamps for a project is not really that helpful.

 

[bob]

Used the Vision software and compared three brands as suggested by suppliers with t8 & t5 versions of each. One brand had a marked difference in distribution.

You need too make sure the fixtures have the same type of lense. Different lenses will focus the light differencly.

 

[ptonsparky]

No lens. Wire guard only.

 

[stevebea]

Used the Vision software and compared three brands as suggested by suppliers with t8 & t5 versions of each. One brand had a marked difference in distribution. Almost like they are intended for aisle lighting in a warehouse and not for gyms. That sales person had no idea what an ies file was. The other two brands are very close in results. T8s are a bit older, are they already outdated?

Outdated? Not in my opinion. While a t5 creates more useable light it does not make the t8 obsolete. T8 systems have proven themselves in extreme applications and have a track record that I do not believe the t5 system has yet. In my opinion they are still " working out the bugs ". Also, some POCO are paying the same incentive on t8 as t5.

 

[Electric-Light]

Right now, T5s are costlier than T8, but I think its just a matter of production volume.

It's estimated that a RE80 lamps cost about 28 cents a lamp in phosphor at production level. As the raw materials go up in price due to shortage of rare earth elements, there's definitely interest to reduce the amount of phosphor used per lamp and with T5s obviously having 5/8 the surface area of T8s, it maybe of interest for the manufacturers.

http://www1.eere.energy.gov/buildin...ial/pdfs/app_3c_lamps_standards_final_tsd.pdf

You most definitely shouldn't retrofit T5 into T8 using adapters, because the shorter length of T5s will cause the lamps to look like they have darkened ends.

For now though, I would go with T8s except for under counter lights where there is a great value in lower profile.

F54T5/HO is also catching on in high-bay, but they compete side-by-side with T8s and I don't have a definite opinion one way or the other. 32W T8s offer better system efficacy (ballast + lamps) although T5/HO system could fairly well have a better luminaire efficacy (system efficacy multiplied by fixture efficiency, which is lumens that leave the fixture per input watt) due to increased fixture efficiency through higher efficiency optics.