Ambient Lighting Everywhere

The color consultant talked about brightening up the house with white paint, and she made a casual comment--white on the ceiling, near-white on the walls, throw in a few wafer lights--you won't recognize the place it'll be so bright. (Paraphrasing.)

There is a reason every house has these wafer lights--they are awesome! Low energy, easy installation, easy to ignore. You put in more than you need and put them on a dimmer. 

I installed twelve 4" Parmida wafer lights in the Workshop in 2019.

The only challenge is getting power to one of them. In BR1 and BR2, we have a switched outlet, so we tap into that. In the Dining Room and Hall, I don't know if I want them on the same switch as the existing overheads, so maybe a new switch. The problem in the Living Room is that the switched outlet and the porch light are jammed into the same 1-gang box. To install a full-size dimmer like I have in BA1, I need more wall. But these are all surmountable.

Less than 24 fixtures ($150 or so), plus an electrician

I'm thinking that if I buy the fixtures and cut the holes, I can get an electrician to give them power. All I need is Romex sticking out of each hole--I can hook up the lights the way I did in the workshop. There are 5 sets on this plan, 5 switches to deal with. Maybe a man-day? Fingers-crossed $1500?

The dimmer switches (like BA1) are Lutron Maestro. They are $32 each at Home Depot--that's more than the wafer lights. But a $300 lights and switches, $1500 labor budget for all that light seems like a good deal.

• Living Room: Switch by front door. (8) 6" wafers = 8,000 lumens, 96W. Color-change for mood. Circuit #3.
• Dining Room: Switch by front door, not by kitchen? (4) 4" wafers = 2,800 lumens, 36W. Color-change for mood. Circuit #3. Living and Dining add 132W to the circuit.
• Hall: Switch by the laundry (TBD). Maybe skip the dimmer? (3) 6" wafers = 3,000 lumens, 36W. Not color-change. Circuit #15.
• BR1: Switch by the door. (4) 6" wafers = 4,000 lumens, 48W. Color-change for mood. Circuit #24.
• BR2: Switch by the door. (4) 6" wafers = 4,000 lumens, 48W. Not color-change. Circuit #24. BR1 + BR2 add 96W to the circuit.

Background

Lighting designers talk about ambient, task, and decorative lighting. Decorative can be anything and task is for sinks and kitchen counters. Let's discuss ambient lighting, now that I own a light measuring device.

Units: Bulbs and LEDs emit lumens (or candelas). My light meter, on the other hand, measures how much light hits a point in space. It displays lux (or foot-candles). The light produced by a 1 candela source on a single square foot poster board held one foot away from the candela is 1 foot-candle. 1 lumen hits a square meter held one meter away for 1 lux.

We seem to want 9 or ten foot-candles 3' off the ground to feel that a room is adequately lit. (This is based on my measurement, not confirmed yet.)

Range of foot-candles: 

BR1 7-8 Fc over the bed, 10-11 at the desk (near the lamp).

BA1 11-15 Fc thanks to 3 LED downlights. At max brightness, 20-23 Fc.

Hall 8-9, depending on how far from the clg light.

Kitchen 20-22, up to 26 directly under a downlight.

Living 6-9, depending on how close we are to a floor lamp. 10.6 near the lamp in the dining room.

Watts to Lumens, from [Lumens and FootCandles MEP Academy] (Candela assumes an apex angle of 56 degrees):

Incandescent	Lumens	Candela
40 Watts	450 Lumens	612 Candela
60 Watts	800 Lumens	1088 Candela
75 Watts	1,000 Lumens	1360 Candela
100 Watts	1,600 Lumens	2176 Candela

I

This diagram illustrates that distance from the bulb matters. An 800 lumen bulb is about equal to a 60W incandescent bulb. FC = Lumens / (distance in feet squared). The Illuminating Engineering Society recommends 100 FC for classroom or gymnasium, 50 FC for offices, 10 FC for hallways.

4" Parmida wafer lights (like I put in the Workshop) are 700 lumens, dimmable, with a 120-degree beam angle. A 12-pack is $70.

6" Parmida wafer lights are 1000 lumens, dimmable, with a 120-degree beam angle. A 12-pack is $60.