Several decades ago, research engineers realized that they would need fluorescent bulbs to work outdoors or under cold temperature conditions.  There were a couple of things to work through, but the most important were starting the lamp in cold temperatures and maintaining a high light output even when the thermometer was below zero.  The development came into what are called generally HO fluorescent light bulbs.  These have a lower starting temperature than standard fluorescents and have a higher lumen output too.  The typical applications are outdoor lighting, sign lighting and coolers and freezers which need a lot of light maintained regardless of the cold temperature.  One of the most common lamps in this category are the four foot T12 which is also known as the F48T12 high output fluorescent bulb.  One of the ways that these are abbreviated is with the two letters HO, meaning high output.  If you ever see HO as part of the code number, you will know that they are HO fluorescent light bulbs.  You will find these in almost any length but the one we're talking about here is the 48 inch version, hence the F48 designation.  Some of the most common codes you might find on this bulb would be F48T12/CW/HO, F48T12/WW/HO, F48T12/D/HO, F48T12/D35/HO,  F48T12/D41/HO and F48T12/DSGN50.  In many applications such as coolers where product is for sale, the daylight or the Sylvania Design 50 will bring out true colors like natural daylight.  These are also referred to as full spectrum.  These are 60 watts which are a higher draw than standard 4 foot lamps which are 40 watts.  The pins on the ends of the bulb are also different, so these are not interchangeable with the F40T12 lamp.

As with all fluorescent bulbs, they rely on ballasts inside of the fixtures in order to make them work. In the case of the F48T12 high output fluorescent bulbs, they can be a magnetic or electronic version.  Either one can work just fine, but the electronic ballast will save energy.  The ballasts for the HO lamps are usually larger than the standard types, and put out a lot more heat.  Some of that is changing when it comes to electronic ballasts as they have a size that is almost the same as the standard electronic ballast.  The old style HO ballasts are very heavy as they have large windings inside.  The ballast is important because it is specific for each type of lamp.  You can't change from one type of fluorescent to another without changing the ballast in most cases.  Most of the time the ballast and the lamp are matched electrically and so it's good to make sure the ballast you have is the right one for the lamp you choose.

You can get the F48T12 high output in almost any color you want including the more desirable full spectrum light, which is our Sylvania Design 50.  The typical choices in the past have been cool white, warm white and daylight, which are the least expensive.  The full spectrum has special phosphors that give it a similar color to daylight or natural sunshine.  It produces light the way our eyes naturally use it, giving better visual acuity and reducing problems like eyestrain.  The term full spectrum is primarily used when referring to those lamps that fall into the white to blue/white color temperature range.  It's these colors that are great for F48T12 high output bulbs because they appear so much brighter and cleaner.  If you have a sign or a cooler which sells product, the full spectrum or daylight color brings out the great colors of product making them more attractive.  That could mean more sales or turning food inventory faster in a grocery store.

Remember that there are many lengths of high output fluorescent light bulbs, but the F48T12/HO is 4 feet long and is commonly used in coolers.  We have a large inventory of HO fluorescent bulbs for nearly every type of light fixture in the field.  It's never a problem to get what you need and Sylvania is our preferred brand of this type of lighting.  If you need help identifying a bulb, our customer service representatives can help you determine by length or wattage what you have.