Kevin C
Well-known member
Lots of discussions on what fixtures to purchase.
Things I have recently learned:
If the fixture has an energy star approval, it must also meet FCC Class B requirements.
How much light you get out of a fixture is determined by a number of factors. One of them is ballast factor. Ballast factor is how much light do you get compared to a reference ballast and lamp.
Low Ballast : .75
Normal ballast. .87
High Ballast 1.2
Why this matters?
Edit:
Comparing T8 bulbs one with a reference ballast factor of 1 you will get 2950 lumens.
At a standard ballast factor of .88 per bulb you will get 2567 lumens (raw output).
With a low power ballast you get 2213 lumens.
With a high power ballast you get 3540 lumens.
A three bulb fixture with a low power ballast puts out less light than a two fixture with a high power ballast.
The problem is, no one seems to list what ballast they use or the ballast factor. That makes it hard to figure out how many lights you will need.
What might help, if you have a fixture that you have bought and you have some experience with list it as a reply. If you can list what ballast it came, cost and basic specs it will help everyone.
To keep this useful, try and stay on topic and keep the replies short.
Edit: I will add info as time allows. If possible, try and keep replies to what fixtures you have purchased and ballast model number. I have data for most ballasts, all I need is the model #. See the second post for suggested format.
Things I have recently learned:
If the fixture has an energy star approval, it must also meet FCC Class B requirements.
How much light you get out of a fixture is determined by a number of factors. One of them is ballast factor. Ballast factor is how much light do you get compared to a reference ballast and lamp.
Low Ballast : .75
Normal ballast. .87
High Ballast 1.2
Why this matters?
Edit:
Comparing T8 bulbs one with a reference ballast factor of 1 you will get 2950 lumens.
At a standard ballast factor of .88 per bulb you will get 2567 lumens (raw output).
With a low power ballast you get 2213 lumens.
With a high power ballast you get 3540 lumens.
A three bulb fixture with a low power ballast puts out less light than a two fixture with a high power ballast.
The problem is, no one seems to list what ballast they use or the ballast factor. That makes it hard to figure out how many lights you will need.
What might help, if you have a fixture that you have bought and you have some experience with list it as a reply. If you can list what ballast it came, cost and basic specs it will help everyone.
To keep this useful, try and stay on topic and keep the replies short.
Edit: I will add info as time allows. If possible, try and keep replies to what fixtures you have purchased and ballast model number. I have data for most ballasts, all I need is the model #. See the second post for suggested format.
Last edited:
