[hellothere123]

Just looking to wire in the wires before we put up the drop ceiling.

I think I can run one wire around the entire area and leave enough slack so that when I put in the lights I can just connect the lights in series one after the other.

Is there a standard spacing or a general rule of thumb on how many lights needed per area?

Thanks

 

[rbj]

Just looking to wire in the wires before we put up the drop ceiling.

I think I can run one wire around the entire area and leave enough slack so that when I put in the lights I can just connect the lights in series one after the other.

Is there a standard spacing or a general rule of thumb on how many lights needed per area?

Thanks

There is commercial specs, but resi permits 3w/sq ft for general purpose. When installing luminaires, it is best to determine how the task or mood lighting areas are going to be located. Determining illuminated areas can be easier to see by visiting the showroom and have a sales person demonstrate the fixture housing reflectivity patterns you want.

 

[AllanJ]

Three watts per square foot is used to determine hoa many amperes your panel and incoming electrical service needs to be (load calculation). Not how much light you need in a room.

Can lights are usually spaced uniformly and intended to light the area uniformly. Additional lights, either on the ceiling or wall, are usually used to accent some areas. As a rough rule, the fixtures nearest the walls are spaced away from the wall half the distance between two fixtures.

Allow two feet of slack in the cable for each fixture.

 

[rbj]

Three watts per square foot is used to determine hoa many amperes your panel and incoming electrical service needs to be (load calculation). Not how much light you need in a room.

Can lights are usually spaced uniformly and intended to light the area uniformly. Additional lights, either on the ceiling or wall, are usually used to accent some areas. As a rough rule, the fixtures nearest the walls are spaced away from the wall half the distance between two fixtures.

Allow two feet of slack in the cable for each fixture.

You are correct. What's the matter with me. I am so used to using [220.42] for general lighting distribution from load calcs that I neglected to mention lamp reflected performance based on footcandle radiated luminosity. Frankly residential does not have a true reference for point or zonal space pattern compared to commercial constraints. Cavity charts that deliniate spacing and uniform surface reflectivity using the Coefficient of Utilization boils down to spacing and distance of lumens to reach walls and the workplane surfaces from the light source.