Normally, there are 20-30pcs LED chips mounted on the base board which made of Sapphire, Ceramic or Bronze. The ultimate heat sourced from the LED chips, then conducted to the gas by the base board and yellow phosphor.

 

The best way to lower down the heat output is to lower down the input current to each single LED chip mounted on the LED Bar. For an instance, the rated input current for a LED chip in a normally bulb is 20mA, for a Filament LED bulb, it will be set in 10-13mA to lower down the heat output, it is the regular current data in the market, but Yunsun set it in 8-10mA for a longer life.

 

8-10mA to each single LED chip makes a much much longer life as the heat is  proportional to the square of current. But it will also result in a lower lumen output, in this case, Yunsun use big chips for our LED bar, normally, people use 9*10mil sized chips in LED bar, while Yunsun use 9*12mil even 12*15mil sized chips for a higher light efficiency and higher lumen output, of course, the cost will be higher, but it deserves to pay 10-20% higher price to get 30-50% longer life.

 

There are some low priced filament LED bulbs in the market, they use just 8*8mil LED chips even smaller and higher the input current to each single LED chip to get a reasonable lumen output, they can sell it at very low price as their cost is much lower, but lifespan is also much shorter.

 

Normally speaking, the lifespan for the filament LED bulb with regular input current 10-13mA is about 1.5 years based on 24hrs continuously lighting every day. Yunsun filament LED bulbs could be 2-2.5yrs with 8-10mA current input, of course it would be longer if you just light up them no more than 12 hours per day.

 

As daily working time affects the lifespan very much, we suggest our customers to give different warranties to their different projects or customers:

Longer than 12hrs working: 2 years

8-12hrs working: 3 years

5-8hrs working: 4 years

Less than 5hrs working: 5 years