date-created: '2010-12-29'
date-updated: '2025-11-28'
manifest-author:
    name: Appropedia
    email: admin@appropedia.org
title: 'ECM - Linear fluorescent retrofit (T12 to T8)'
description: 'Download ECM now! Bulbs for fluorescent light fixtures come in various guises, but two common versions are the T12 and T8. In these names, the ''T'' refers to the bulbs tubular shape (with electrical connections at both ends), and the number is the diameter of the tube measured in eights of an inch; that is the T12 has a diameter of 12/8" or 1.5", while the T8 has a diameter of 8/8" or 1". Generally speaking, the smaller diameter bulbs are more efficient light emitters, as is the case on the T12/T8 bulbs (40 W versus 32 W). While this works well in theory, a survey of light products offered by GE shows T12 40W at 3400 lumens and T8 32W at 2800 lumens, yielding approximately the same light intensity per watt.'
intended-use: 'saving energy'
keywords:
    - 'energy saving'
    - 'Energy conservation measures'
    - 'Energy audit'
    - 'Energy efficiency'
    - Finance
    - 'T8 bulbs'
    - 'linear fluorescent retrofit'
    - 'T12 bulbs'
    - Engineering
    - Lighting
project-link: 'https://www.appropedia.org/ECM_-_Linear_fluorescent_retrofit_(T12_to_T8)'
contact:
    name: 'User:M. Urquhart'
    social:
        platform: Appropedia
        user-handle: 'User:M. Urquhart'
version: 30
development-stage: Verified
made: false
variant-of:
    title: 'Green IT'
    web: 'https://www.appropedia.org/Green_IT'
license:
    documentation: CC-BY-SA-3.0
licensor:
    name: 'User:M. Urquhart'
    affliation: 'Category:Queens University, Kingston'
    contact: 'https://www.appropedia.org/User:M._Urquhart'
documentation-home: 'https://www.appropedia.org/ECM_-_Linear_fluorescent_retrofit_(T12_to_T8)'
documentation-language: en