Sunday, May 26, 2013

Super Energy Efficient Lighting for Low Energy Buildings

There is a lighting revolution going on right now - just as there is a solar energy revolution and renewable energy revolution, and energy storage revolution!  I don't remember anyone predicting that after the information age began, we would be going through a major shift in energy and infrastructure.  And this is not to mention Passive House.  I feel like saying people building standard houses today will face some significant obsolescence issues within a few short years - namely in energy, IT, and lighting.  At first these seem like parts of the house one can easily change - but the energy aspect is a big one, and certain things are really hard to justify changing - like missing out on good solar exposure, major thermal bridges, and insulation values that don't cut it.

About the lighting:  Cree announced in December they have an LED that offers 200 lumens per watt (!).
Here's the press release:

If you are in the big box hardware stores, take a look at the LED offerings.  They are all hovering around 60 lumens per watt right now, if you get a good one.  Most are at 50 lumens per watt, often less.

How to get highly efficient lighting without spending too much?  Low Voltage distribution.
Watch the Video on What Is Lumencache:

It seems the thing to do is to separate the COB (chip on board - which is the actual LED chip) from the power supply.  This has two advantages:  purchase a single, centralized, high-efficiency, high-efficacy power supply; and then reduce the cost of the actual luminaires.  All those backward-compatible LED bulbs you can buy to replace the bulbs in your existing fixtures have the significant issue in their design that they have to have an on-board power supply, which is cheaply made to reduce costs and therefore, not that efficient. This also means the cost of those low performance power supplies is included in every bulb.  Eliminate this circuitry and you can improve the lighting.

So, we wire the house as per the Lumencache strategy, but there is another issue to handle.  LED's are pretty sensitive to voltages and current.  Say we have a living room with 12 LED luminaires, each one with nothing more than the COB in the luminaire.  We need to arrange these luminaires into groups that match the voltage and current output of the central LED driver system, or at least keep the demand within the range of output levels available at the central power source.


  1. The Markham-based company GL-Light has such LED fixtures. These fixtures do not include the AC to DC transformer modules. You supply each fixture with DC only. This allows them a shorter profile also, and it likely means that the top of each fixture can busy itself releasing heat, not trapping that heat within a power supply unit sitting atop the heat producing device. The ones I saw at the green living show a couple years back were barely thicker than a 5/8 inch piece of drywall. I assume that this also means you can use them without a housing meaning more room in the ceiling for insulation. And you can likely wire them with doorbell or thermostat wire, so less copper needed.

  2. We build homes and other spaces to a visual standard, and not to be rebuilt. My East York bungalow's plumbing is encased in drywall, screws and mud. Part of the beauty of the low voltage lighting system described above is that the luminaires can be easily removed from the ceiling and since their wires need not have been stapled to the joists, they can be used to pull in new wires or to reconfigure such systems if necessary -via forethought during the initial installation (large holes through joists; strings run during the install allowing optional routes, etc) Hiding infrastructure was fine back when infrastructure didn't change.

  3. People those lot of money they are finding home that are equipped with modern facilities as you have mentioned in this blog. So it is easy to search homes in Toronto that provide basic facilities.

  4. I agree with what you said in this article. Thanks for your insight. If you are ever looking to buy or sell a passive house, York Region Homes is an excellent choice!

  5. As you are living at the age to technologies. We are blessings by the science revolutions. In the last decades are using traditional bulbs as we have no other options to choose. Now LEDs & CFLs bulbs have arrived and make a new era in lighting technologies. People often call these as future lighting technology.

    low voltage lighting

  6. I just for the first time installed strip-style LED countertop lighting in a kitchen reno. It came on a roll 5m long from an electronics distributor in Mississauga. I bought the larger (4amp) power supply. There is a slight delay before illumination. I am wondering if through using the smaller power supply (2.5amp) instead this delay would either be shorter or non-existent, since its a smaller set of components inside (capacitors especially) being booted-up each time it receives power from the 110vt switch. I haven't tried the 2.5amp supply yet to see if its any quicker to start. I'd also like to find out if the low-voltage (12vt DC) circuits of such a system can be switched via standard high-voltage (110vt AC) light switches. I don't see why not -other than maybe some internal arcing with extended use. (?)(Circuits could also be fused?) Anyway, it lit the countertops very well especially since they were not glossy countertops, more like the satin finish of a laminate. This diffused the reflection of the LED strip (whose LED's are about 1 inch from each other). These are important in the look of the finished product since you don't want to be looking down at a row of LED's reflected back up at you. By the LED's being so close together it is easier that they all diffuse into a single beam of light when reflected. However if the countertop were glossy I fear that they would be annoyingly visible even at the 1 inch spacing; this is something to think about as we design spaces lit by this new technology that is so very different in its effects from the tubes and point-sources we are used to having around us...

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  8. I am friends with your across the street neighbours and they told me about this as I am interested and passionate about sustainable living. Is it possible to come for a tour?