Bypass or Not?

When installing T8 LED tubes, we get a lot of questions regarding whether or not to bypass the ballast or not. Hopefully this information will shed some light on this issue.

 BypassedRetrofitRecommendation
InstallationTakes around 15-20 mins per tube. This extra time amounts to added labour costSimple install, remove the casing, old light and starter place in a new light and starter.Factor in the extra time it takes to complete the job and the opportunity cost it takes whilst the light is being installed
EfficiencySince the ballast is bypassed the efficiency of the tube is not affected by the ballastIf the ballast is left in tact, depending on the type of ballast, age of ballast, efficiency of the light can be reduced by anywhere between 0% to 20%If you are committed to LED’s bypass the ballast as you are rewarded with higher efficiency. If you are just trialing retrofit.
SafetyAll bypassed tubes are tagged with warning sticker to only use LED tubesAs the fixture is unaltered, no safety concernsOnce a ballast is bypassed non-compatible lights will not be functional.
SoundWithout a ballast, there is no humming or buzzing soundAlmost all ballasts hum to some degree, with magnetic ballasts humming more than electronic ballasts.Advantage goes to bypassed systems as there is no ballast and no sound.
LifetimeBased on the lifetime of the tube. Rated on average at 30,000 hoursThe lifetime is based on the LED tubes and the life of the ballast. Ballasts can last anywhere between 30,000 hours and 80,000 hours depending on type and usage.Once the tube has exceeded its lifespan, In a bypassed system only the cost of new tubes will be factored. In a retrofit system, the cost of both fixing or bypassing the ballast and new tube need to be considered
CompatibilityBallast compatibility is not an issueNot all tubes work with all ballasts.Know which tubes are compatible with which ballasts before doing a large upgrade.
FutureMust always use specified tube in the fittingCan be interchangeable with regular fluorescents at any time.If wanting to go back to regular fluorescent tubes, retrofit fit, otherwise use LED tubes for the remainder life of the fixture.

So which is best? It really depends on the situation. Generally, if you are seeking a permanent reduction to your energy bill, bypass the ballast as this will only allow the use of energy efficient products. If you are looking for a temporary saving, retrofit but bear in mind, not all existing ballasts will be compatible with LED tubes.