Wednesday, February 24, 2016

Trial Placement of LED Disk Downlighting

What shall I do to add cheerfulness and function to the ceiling of this residence Music Room? 

The home owner has lost patience with a Good Earth Lighting, Model No. G4150_BN-I luminaire of superseded design needing impossible-to-find ballast and using two hard-to-find 26 watt CFL bulbs with plug-in base. Dim, not pretty, not bug-proof, more than $150 already invested.

I want to illuminate the entire room uniformly. with LED lights distributed upon the nine-foot ceiling. In Winter 2016, choose Nicor DLS4 , 671 lumens.

Pegasus Lighting offered this free advice, prominent in Google search:
Helpful rules for lighting placement:
How To Layout Recessed Lighting In 4 Easy Steps 
Lesson 3:
To determine how far apart to space your recessed lights, divide the height of the ceiling by two. 
Lesson 4:
Make sure to place recessed lights approximately three feet away from the wall.

Here is another set of rules, inviting in its avoidance of word "recessed:"
Downlighter Spacings 
The Chartered Institute of Building Services Engineers, CIBSE,  is cited, from London:
CIBSE code for interior lighting .

For this 10' by 15' residence Music Room, choose: Illuminance = up to 300 lux. Five 671 lumens Nicor DLS4 well-placed is suited to CIBSE advice.The Music Room area is 14.5 sq meters. Average illuminance is 5*671/14.5 = 231 lux. 

(I overlay plans on a satellite photo of the home.)

As noted, lighting that began with Nicor DLS4, 671 lumens each, 3000°K in a Music Room, became all Utilitech 0752125, 700 lumens each, 3000°K. The 4" DLS4 lights were uncomfortable to gaze upon.

Discuss the initial installation of Nicor DLS4:
Despite attention to advice, proceed with caution. Mount lights temporarily. Flatten the ground tab of each box-mounting bracket and attach to the ceiling by a single drywall screw, loosely set.

One bracket center is of the found light. Four more were mapped by the rules.

The pigtail of each light is accessible to bell wire attachment.

Let there be temporary light, on-approval overnight.

At positions now-committed, trace and cut in RACO 175 junction boxes.

I have generously used pencil markings. All excess markings are gently erased in scrubbing with wet flexible grout.

Use a jab saw for junction box cuts.

Use a handsaw for access cuts.

Take care to not drop the access drywall, that must be reset.

After much mapping of nails with a strong magnet there are no surprises. The single romex wire of the found light has troublesome staples that must be pulled. The wire end will be pulled back, to first serve the box beyond the access cut seen in this photo.

Mass-produce box supports.

Some care is needed to affix a Nicor DLS4 to its bracket. Clips deform often with the difficult blind push, coping with lead wires.

The access patch is time-critical, with setup time needed in repeated application of flexible grout. Taping is never needed with well-supported edges and flexible grout. The entire ceiling would need leveling and new texture, if dryall tape were employed.

 Just vee all patch edges to a 3/32" gap.

The still-wet access patch shows in this photo, but will be invisible after the ceiling is next painted. This is good progress toward a better future of starry skies lighting. Lights will be beautiful crystals, not recessed, less bright than this. I wish for a 450 lumens unit of light, a pattern of about eight lights in this room. No 450 lumens luminaires are on-offer. When they are, let there be a sprinkling too of 300 lumens lights to randomize patterns. Maybe a brighter light now and then, to further randomize. I wonder if we will find alternatives to fairly aggressive cuts, and patches, for access. This access cut is in fact quite small, where I could count on directing wires via 3 1/2" cuts for junction boxes. I wish for low voltage wiring of lights without junction boxes even; but have things to learn about fishing such wires blindly.

At 3/20/2016, report disappointment with the tried Nicor DLS4 lights. I find that they are too bright to look at, even on a nine-foot ceiling. The DLS4 lighting density, lumens divided by circle of intense light, is higher by about half, vs. Nicor DLS56 or Utilitech 0752125, amounting to design error in Nicor DLS4. 

Utilitech 0752125 have replaced the Nicor DLS4, brightening the room  by 4%, while being much easier to look at. The lights with less glare are less confusing to a camera too, evident in better focus.
Utilitech 0752125

Nicor DLS4

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