Universal Lighting Technologies

High Bay Solutions

What is the Opportunity?

Converting from T12 magnetic ballast systems to T8 electronic systems has been generating sales revenue for years. With recent developments in lumen technologies, many of these same customers now have additional energy savings opportunities with their HID lighting. Warehouses, gymnasiums, and even some retail installations are lit with HID sources such as Metal Halide and High Pressure Sodium. However, HID is plagued with problems like long start times, noise, and color shift variations. Should the power blink, HID is off for 15 to 20 minutes. The heyday of HID has passed. Higher efficiency fixtures with instant on/off capability and quieter operation are now available. And to make the sale even easier, many utilities are offering rebates for replacing HID fixtures, which will reduce the payback time.

What are the Options?

Out of a sea of many options, there are two that make the most sense. Fixtures utilizing T5HO or high lumen T8 fluorescent lamp technology are the most appropriate choice if the space is temperature controlled. Fixtures using electronic HID (e-HID) lamps make the most sense when there are wide temperature changes. This is because the lumen output of fluorescent lamps drops off when it gets overly cold or hot. However, “amalgam” T5HO lamps have recently been introduced to improve their ability to operate over a much wider temperature range. T5HO systems have become quite popular because they provide more lumens than T8 lamps, thus minimizing the lamp quantities in a fixture.

Occupancy Sensors?

Just like in the days of T8, when using T5HO and occupancy sensors as part of your energy saving sales pitch, promote the Programmed Rapid Start (PRS) type electronic ballasts. Most manufacturers have PRS ballasts available in T5HO. If your customer does not want to use occupancy sensors, then promote the Instant Start (IS) technology. These ballasts save an additional 4% energy! Though not as widely available, they are marketed by big name ballast suppliers such as Universal. Luminaire manufacturers have the ability to install both types within their fixtures.

How much energy can be saved?

Assume you sell your customer on a T5HO fixture replacing a 400W MH HID fixture. That HID fixture was using 458W. The equivalent 4-lamp IS T5HO fixture, which delivers 91% of the light, is only using 226W for a savings of 232W—a 51% savings! Not only are you giving your customer a huge energy savings, the quality and color of the light easily makes up for the 9% reduction in measured lumens. This new fixture is also deftly quiet, has instant on/off, and is even dimmable, if specified. Should there be the need for extra light, say if the space was originally under lit, then a 6-lamp T5HO fixture can be used. This gives 19% more light and still saves 119W. That’s a 26% reduction in power for 19% more light!

If your customer’s space is unconditioned, e-HID could be installed in the fixture. Universal’s eTensity product line is an example. For that same 400W MH, pairing the Universal 320W PSMH ballast with a 320W PSMH lamp gives your customer a 113W savings with 5% more light.


In areas of the country where rebates are offered, such as California, Texas, and the Northeast, HID replacement moneys are available. Many utilities are offering up to $75 per T5HO fixture and additional money if controlled by occupancy sensors. Consult the utilities in your area of sale for information on current and upcoming rebate offers.

Bottom Line

HID’s time has passed, and there are vastly better solutions using T5HO lamp and ballast combinations. How can your customers afford not to replace them?