Passive house lighting: most energy efficient LEDs (and CFLs)
Ecosmart/Cree LED Recessed Lighting from Home Depot
Now that we had our passive house ventilation and passive house heating and cooling systems in place, we began focusing on other ways of reducing our electrical energy requirements. The next area to consider was lighting. First and foremost, Lisa and I designed a bright house, that is one that gets most of its lighting naturally, yes even at the expense of some heat-retaining performance. While it is most certainly true, that buildings built to the strictest Passivhaus designs will require the least amount of active heating or cooling, we wanted a home that was especially liveable and for us that meant lit with as much natural lighting that was practical We were not interested in living in a bipolar house (consisting of bright and dark sections)--when it came to lighting--just for the sake of extracting the absolute best number on a spreadsheet.
Our property is located on a quiet and private multi-acre lot that has a beautiful view of the woods in our backyard and the wildlife that lives there. We didn't want to forgo that for the sake of maximum heating performance for what amounts to about two and a half months out of the entire year. Early in the design of the house, we considered the use of overhead Solatubes to harness natural lighting from the rooftop as a more efficient efficient alternative to conventional skylights. We eventually discarded both approaches because either approach penetrated the exterior building envelope, were still too ineffective at insulating, and provided light from overhead (the least desirable form of lighting). Instead we designed a home with a very open floor plan, one devoid of hallways (which are always "dark" and confining) and one with a generous amount of window glazings, especially on the south side. When ambient light is insufficient, we opted to use Ecosmart LED for all recessed lighting, made by Cree. We were able to purchase these in bulk from HomeDepot for merely $24.99 each at the time (yes it is a lot by conventional bulb standards, but less than what they once were of $40-$50). These bad boys are incredible--outputting the 65 watt-equivalent of 575 lumens at merely 10.5 watts at maximum brightness. When dimmed to more reasonable levels, their power consumption drops even further. The light output is wonderful and well diffused.
We have found Home Depot to be far better at promoting energy efficient lighting than its counterpart Lowes. One of the nice features of these Ecosmart (Cree) designs is that they are integrated with recessed lighting covers and easily fit into new and retrofit recessed lighting housings. The color temperature is also very desirable at only 2700k. We avoided the use of CFLs because of their use of mercury. On the exterior of the house, we used LED spots and CFLs for wall and patio lighting. For the two main chandeliers, we used 9 watt LED bulbs. We also opted for LEDs for under-the-cabinet lighting.
One thing to keep in mind is that these newer lighting systems require dimmers that are capable of handling them properly. If dimmers are mismatched, flickering (especially with CFLs) and humming can occur. Since this was new construction we weren't constrained by such issues, we selected Lutron smart dimmers throughout the entire home which were capable of not only dimming conventional incandescents, but LED and CFL as well. To be sure, these selections were not inexpensive, but my wife and I were satisfied that we were supporting (as early adopters) the continued production of even more reasonably priced and higher-performing lights that will most assuredly become available in the future. Plus they're cool!