LED Surface Mount Light Energy Savings At True Brightness Ratings

Versus point-source lighting, there is a  beneficial shape factor of about two, for naturally-directional LED illumination. I have proven this in side-by-side comparison tests. It is explained here: 
http://www.firefly-technology.com/resources/How+Bright+is+that+LED+Bulb.doc
This link leads to download of a Word document. If you prefer, view it online, attributed to Firefly, as PDF.

Since about half of the illumination from an LED chip array is lost in shaping as a point-source "bulb", there will be little use in the future for fixtures that present light as a point source. Directional light, then rated for illumination  brightness rather than omni-directional lumens, will always be more efficient. It is the presentation of the light that matters, and there will be surface mount LEDs fed through A19 and other sockets, upon light cans and other fixtures.

At end of January, 2013, I recognize two good LED plate lights, produced by Lighting Science Group, as product Glimpse. Let us compare operating costs of Glimpse, and other currently-available lighting,  unitized to Brightness Number 4, that of the old 100 watt incandescent light bulb. That is, for illumination other than B4, multiply costs and savings by the ratio (4/ Brightness number), for same-basis comparison. Where illumination from a given source location is increased, fewer neighboring lights are needed, or productivity improves in direct proportion. If you want that "100 watts", and a Glimpse light is brighter, you might dim it, without waste of energy in the dimming.


Here is a Table of luminaire cost and savings comparisons, adjusted to a common basis at B4, except that there is further economy in installation cost of surface mount LEDs. The table displays dollar value and greater carbon savings, taking credit for a brightness advantage of surface mount LEDs, vs. all light in bulb form. The listed CFL is not dimmable, and gives dreary light. I think its lifespan is very overrated. Surface mount LEDs do win over CFLs on lifetime cost. Bulbs that fail have additional cost disadvantage in matters of safety while dead or in replacement. Aren't we happy to now have mufflers that last the life of a car?

(The table has been updated 6/6/2013 to include important Sylvania LED Disk Lights.)

Well, now, how do those savings numbers compare to listings on packaging?

Package math is for electricity only, and credits the T91 as equal to a 75 watt incandescent. Savings:
 35,000 * 0.11 * (75 - 14.5 )/ 1000 = $233.

I don't understand the sloppy math of this packaging.







Let me re-do my math of this T91, for electricity only, with brightness as of a 167 watt bulb:
35,000 * 0.11 * (167 - 14.5)/ 1000 = $587. There is more at issue here, than how to do math.

Package math is for electricity only, and credits 100 watt equivalence. Savings:
 10,000 * 0.11 * (100 - 23 )/ 1000 = $85.
This isn't error. It is permitted propaganda.

Who is responsible for not standing up against deception? 

LED Lighting In RACO 175 Junction Boxes

Here are PDF albums showing installation of LED lighting in RACO 175 lighting junction boxes, in a new bathroom ceiling. I detail the procedure where one person does the work, with a few trips to the attic. Even with multiple workers, a safe attic ladder and attic lighting are important to getting the job done safely. 

As a procedure for a 4" Glimpse LED plate light.

There is a single Romex power cable here twist-connected to the kit quick-connector. LSGC instructs removal of the ring terminal on the green fixture ground lead/ security wire. Why? I have here attached the ring terminal to an 8-32 fixture mounting screw. It will be better to "bond" the ring terminal at the box "green screw", if all attachment at the green screw is with ring terminals.

Where professional electricians become involved with a national LED conversion campaign, I wonder what they will bring to further evolution of the hardware.

As a procedure for a 6" LED  disk light, Home Depot T67.

Please follow the link, for more discussion of grounding provisions and sensibility of hardware.















Please contrast this achievement of air-tight strong installation,  to what most people will expect, using a plastic box in a T91 installation. Where a box is not solidly set in the ceiling, it is hard to complete a seal around it. The seal is less important than the reduced power draw, but it is silly to skip maybe 20% of the potential savings vs. poor incandescent lighting.

Campaign Against Can Lights

I speak up for a new wedge to get existing-home owners engaged in weatherization: getting rid of attic floor can lights. Let us call the absurdity of do-gooder weatherization in free CFL bulbs and flow-restrictors on shower heads. Let some weatherization contractors and lots of licensed electricians earn some needed income with for-free, publicly or utility-funded difficult elimination of dangerously-fried ceiling light junction boxes or crudely hacked-in can lights whether air tight IC, or not. Here is a message I have sent to Conservation Services Group, my chapter of Home Builders Association, Energy Trust of Oregon, Lighting Science Group Corp., NEEA,  and now on to any reader:

As an installing contractor and blogger, I have been an early adopter of LED plate lights. 

These lights are made by Lighting Science Group Corp. as Model "Glimpse", the first consumer product offering direct wiring into a junction box. I have been working since September 2011 with Glimpse lights in 6" size, packaged by Home Depot as Commercial Electric Product T91. I have been watching and prodding, that Home Depot should also offer  4" Glimpse luminaires, available since February, 2012. Posts of my experiences are readily found in relevant internet searches. Topics include details of installation, compatible dimmers, an adventure in the availability through Home Depot, and now advocacy for alternative distribution and marketing. Happenings in availability have caused me to at last employ distribution other than Home Depot, and at last to try out the full six-member family of Glimpse lights, two sizes, three color temperatures. I am doing what I can to interest Lowe's in stocking the Glimpse family. I have appealed through the Energy Star Hotline, that brightness ratings of plate LEDs should be redefined, doubled. I have appealed to Lighting Design Lab (Jeff Robbins), in Seattle, to have the same interest I propose for CSG. I will watch for the CREE lights to be stocked now by Home Depot in lieu of Glimpse shelf space, and will use and report upon them as appropriate.

My drive is to eliminate attic floor can lights, as permitted with LED plate lights.  I believe the simplest and most satisfying saving opportunity in residential weatherization is in that one measure. Good lighting, not choked to save energy, adds much to productivity and quality of life. Here is demonstration in that belief:

Insulation Math - Phillip Norman Attic Access

sites.google.com/site/phillipnormanatticaccess/Home/insulation-math

Example 7: One baffled can light in every 100 sf of an "R38" attic floor. Say, cellulose twelve to fifteen inches depth. Real R38 insulation except for holes.

Typical $1 per year heat loss per can, plus excess cost of electricity. For electricity cost assume a maritime climate with $0.15 per KWH electricity cost. Consider a light that is on 4 hr per day, 1460 hr per year, Cost is $14 per year at 65 watts and $3 per year at 14 watts. Each change-out saves about $12 per year per fixture. Simple payback is in five years if total replacement cost is held at $60 per fixture. This is irreversible repair of a heat bleed, far better than putting a 23 watt CFL in the leaky can, $5 per year electricity cost, only $9 per year  saving of energy. We are looking for fullest easy, painless energy savings, not fastest payback of any investment. Lots of skilled electricians and other workers can find employment, in the permanent repair. The campaign would accelerate deployment of LEDs in general, at reduced cost.

The campaign includes global recognition that plate LED's are in a new realm of illumination efficiency. LED manufacturers somehow are restrained against true claims of achieved illumination, The 4" Glimpse is labeled as equivalent to 45 watt incandescent, when in fact they match the illumination a 100 watt bulb. A 6" Glimpse labeled as  match to 75 watts, is better than a 150 watt bulb, and never gets hot. Fixing the involved standards will be a lot of fun.

There are other things possible with insulation and sealing in many homes, with payback in less than ten years. But, many are harder and less certain of delivery. Those bleeding energy, need to start somewhere.  All should be done. Why reject the can campaign? Let it also motivate better new home construction, always with LED plate lights, allowed inexpensively by appropriate wiring provisions. For plate LED possibility, all junction boxes must be larger "deep" sizes, and must not be burdened as circuit junction boxes, carrying more wires than needed for the light operation.

Please note separate assessment of potential savings in reduced electricity consumption, and in getting rid of air leakage and missing insulation associated with can lights. The saved electricity vs a 65 watt spot bulb matters most.

The potential energy savings often are less significant than the elimination of fire hazards where a blow and go criminal does not call in an electrician before doing his deed. Better light at a tenth the cost improves national health and productivity. We might cure a few SAD sufferers, and why not for-free?

Electricity Usage History, My Home

I will look mainly to consumption of natural gas in tracking consequences of weatherization efforts in my home. Yet, I will find lessons for this study in what is offered by my electricity utility. 

My electricity serves a hot water heater, lights, computers, and, until five years ago, a clothes dryer. No electric space heaters. I expect seasonal  variation in operating the air mover of my furnace. I don't know what I might find in being attentive to billing details, and expect charts will not inspire changes of behavior. Here is the best information I may see online at the web site of my electric utility, Pacific Power. It is a bar chart of KWH differences between meter readings, going back two years. Is that what I want?

This chart is sufficient to see that electricity usage is proportional to the number of adult inhabitants, where I had a boarder for three years, ending mid-Winter, 2012. I have all of my bills going back to 1998, and ending November, 2012 when I switched to paperless billing. I can continue to see all details of billing, into the future, with online posts of billing. I wonder what more I can learn from the numbers.  With a significant investment of time, I typed numbers into a FileMaker database. That gives me entry ease, and calculation functions I might not understand in Excel. I readily save the data into an Excel file for a variety of plotting interests. 

A first plot lets me see back to first consequences of sharing my home. A hardly-believable spike in 2009 might include consequences of using CRT computer monitors and a television set. Questioning the spike, I had my meter tested. It's a good digital meter, installed In January 2006, and works just fine. Maybe the boarder did stay toasty with a space heater.

I think I demonstrate to my utility, that line charts are better than bar charts, and that sometimes-large variation in the number of days between readings should be accounted for. A plot of average KWH per day for reading periods is cleaner, and is no more difficult to generate. Charts going back as many years as possible will do a lot more to influence behavior, seeing through seasonal variation.

Online charts must not leave out dollar amounts. Dollars are easier to understand, where some motivational lesson is offered. Dollar amounts will retain the "noise" of variable days between readings.

I go further to test whether rates are applied as we might expect. Here is the variability in rates applied in my billing:

Is anything wrong here? In the Pacific Northwest, most of our electricity is now from coal-fired power plants, not from our hydroelectric dams. I suppose it is fair that we are losing our "cheap" rates. Subsidized cheap power is not good for motivation to conserve energy, so, good riddance. Save our salmon.

Accepting comment, I admit surprise my electricity cost is moving up to national norms, and not due to coal-fired generation. My marginal rate remains under $0.10 per kwh, but as I use less, the $9 per month basic charge rules. That saps inspiration  to conserve. If more people see this, we might act to lower or eliminate the basic charge, boosting the delivery charges. 

Here is an update of my information through October, 2014. I continue to benefit from 2008 conversion to a gas clothes dryer. Really-dramatic improvement since 2011 is from conversion to LED disk lighting, a 90% reduction of employed electricity.

Where billing periods range from 26 days to 39 days, a chart including dollar amounts has more scatter. Through the scatter, see $15 per month savings from conversion to LED lighting.

My utility offers only a bar chart option, of KWH usage for each billing period. It means nothing to me.

US Department of Energy Does Weatherization?

Edit at 6/15/2016: The offending US DOE web page no longer exists!

US DOE proudly offers this bad advice dated June 24th, 2012:
Estimating the Payback Period of Additional Insulation 


EXAMPLE
Suppose that you want to know how many years it will take to recover the cost of installing additional insulation in your attic. You are planning to increase the level of insulation from R-19 (6-inch fiberglass batts with moisture barrier on the warm side) to R-30 by adding R-11 (3.5-inch unfaced fiberglass batts). You have a gas furnace with an AFUE of 0.88. You also pay $0.87/therm for natural gas. Let's also suppose that you supply the following values for the variables in the formula.

C(i) = $0.18/square foot

C(e) = ($0.87/therm)÷(100,000 Btu/therm) = $0.0000087/Btu

E = 0.88

R(1) = 19

R(2) = 30

R(2) - R(1) = 11

HDD = 7000

By plugging the numbers into the formula, you obtain the years to payback:

Years to Payback  =  (C(i) × R(1) × R(2) × E)   ÷  (C(e) × [R(2) - R(1)] × HDD × 24)

(Note to USDOE/ NREL:  Your web page needs repair.)
Anyone will know about "diminishing returns" with piling on blankets.


Years to Payback  =  (0.18 × 19 × 30 × 0.88)   ÷   ($0.0000087 × 11 × 7000 × 24)

90.288   ÷   16.077   =  5.62 years



Same Example, Phillip Norman Attic Access

https://sites.google.com/site/phillipnormanatticaccess/Home/insulation-math 

I pay $0.203 per sf for Johns Manville R11, after recent 10% increase for lack of demand where weatherization is NOT HAPPENING, and bid as times 2.5, installed total cost, or $0.509 per sf.

Natural gas costs more than $0.87 per therm. I pay about $1.20 per therm for natural gas heat, and know real cost with fracking permanent ruin of lands and water, and with war to fuel subsidized Hummers and corporate jets, is higher, maybe times ten. Real cost should always be used when rationalizing public policy. I use $2 per therm, a LOW number.

Annual cost of heat lost through insulation is:
 $2.4 * 7000/4400 * (1/(Ri + 3)), per sf.

Annual savings R30 vs R19, are:

$3.82 * (1/22 - 1/33) = $0.058 per sf.

Simple payback with professional install is 0.509/ 0.058 = 8.8 years. Or, with self-install, divide by 2.5, for result 3.5 years.

Don’t stop at R30 though, despite slowing of payback with added insulation.

Add to R38:
Ci professional install adding unfaced R19, is $0.316 per sf * 2.5 = $.790 per sf.
Annual savings are $3.82 * (1/22- 1/41) per sf = $0.080 per sf.
Simple payback, professional install, is .79/ .08 = 9.8 years.

More-correct math does not change the picture. There is broad agreement we should have a lot more than R19 in our attic floors. Let's just do it. But DO NOT ADD MORE INSULATION before finding and closing attic floor pits, fixing enclosed fans and ducts, and replacing bad wiring in the process of conversion to LED lighting. What does US DOE have to say about any of that? Just bring out the blower door and wish all your troubles away, we understand. Send workers into an attic with a can of foam, and no contract to find and fix the greatest energy losses.

US Department of Energy knows nothing, and does nothing here. They must not be immune from criticism. Will they come clean, and rid us of phony HPwES ? In hard times, can we deprive them of funding to do careless work?

I think we should fully defund US Department of Energy, if it must remain the originator and maintainer of evil nuclear weapons. All within USDOE, and in state Departments Of Energy, are corrupted by this association, thus advocacy, of WMDs. This grousing is added 2/8/2014, where I have once again tested, to see that the stupid post by USDOE is immune from public comment. Know I have made calls directly to USDOE (some powerless answerer at Booz Allen Hamilton), and to NREL, to no effect.