|Metal halide fixture|
Bright Ideas Lighting Co. recommends removing these old fixtures and installing new highbay fluorescent fixtures. Typically the energy savings is 50%. The most common type of fixture like the one pictured above is a 400 watt metal halide. These typically take about 5 minutes to come to full brightness. The ballasts on these fixtures typically have an audible humming noise.
The 400 watt fixtures can easily be replaced by either 4 lamp T5 HO fixtures or 6 lamp T8s. If your business is in Idaho, the Idaho Power rebates are $90 for the T5 HO fixture and $120 for the 6 lamp T8. Since the cost of the two fixtures is approximately the same most projects are going with the 6 lamp T8 high bay fixtures.
The fluorescent fixtures come up to full brightness quickly, almost instantaneously, so you can turn them off and on without having to put up with the 5 minute warmup time for HID fixtures. Also the fluorescent fixtures can have occupancy sensors attached so that the fixture will partially turn off when there is no one nearby.
At Bright Ideas Lighting Co we just completed a project where we replaced almost 100 of the 400 watt metal halide lights with 6 lamp T8 and getting a tremendous energy savings and Idaho Power rebate for the customer.