Sunday, October 23, 2011

Lighting Efficiency Summary, 2011

This list is taken directly from a Martin Holladay article at GBA:

Here are some relative lamp efficiencies:
  • "Indancescent bulbs produce about 14 to 17 lumens per watt.
  • Low-cost LEDs produce about 15 to 25 lumens per watt.
  • High-quality LEDs produce about 40 to 70 lumens per watt.
  • CFLs produce about 48 to 60 lumens per watt.
  • T-5 and T-8 linear fluorescent tubes produce about 98 to 105 lumens per watt."

And I just found this increased efficiency LED bulb that kicks out 94.4 lumens/watt:

Even though in the article Martin states:
  • "For now, screw-based CFLs are the best bulb choice for residential lighting.", I think LEDs have just reached the tipping point. 

Sunday, October 9, 2011

How Does the Demise of Big Builder Magazine Relate to Southwest Denver?

As I've been saying for a while, destroying greenfields in exurbs is a business model that is slowing down and may end for a long time.

A symptom of this is the announcement of the end of Big Builder Magazine.

If there are any Big Builder types thinking of what next to do with their lives, here's an idea:

Start a land bank in SW Denver, where there are hundreds of homes available for $50k to $100k.  These prices don't seem to be going up any time very soon, but they are very competitive with the cost of greenfield lots.  Throw in the fact that they are eight times closer to the jobs and entertainment of Denver's city center, and you start to think they may eventually be worth a lot more than those far-flung lots.

Now add in some recent pro-density changes in Denver's zoning code, and you have a pretty compelling business model.

Friday, October 7, 2011

2011 LED Lighting Update

At $10, LED light bulbs finally make sense for your most-used fixtures.

For green home designers, it means you should stick with medium base fixtures everywhere.  The LEDs also operate plenty cool enough for those small closets with shelves.  I'm not sure how you will convince the building inspectors, but when incandescent bulbs are illegal, that should solve the problem.

Some folks aren't fully convinced:

But these holdouts won't be promoting CFLs much longer.   Economics and common sense will bring them around.

And remember, CFLs still suck