Comments on: What Is the Difference Between Energy Efficiency and Efficacy?

By: Matt

Matt — Thu, 15 May 2014 19:55:30 +0000

I like that. My first thought
I like that. My first thought when I read "And you'll look even smarter when someone asks why you're using that word instead of efficiency." was also that people will look at me like I'm stupid for mispronounce efficiency. Oh well. Thanks for the heads up

By: Ernest Murry

Ernest Murry — Wed, 14 May 2014 21:56:12 +0000

I very much like the
I very much like the distinction between efficiency and efficacy. Efficacy … meaning “the ability to produce a desired or intended result”.
All too often sealing ducts, insulating ceilings and walls, properly sizing equipment, reducing infiltration and many of the other aspects of building performance are spoken of solely in terms of energy efficiency… but what about comfort? The “intended result” of most buildings and their mechanical systems isn’t to save energy … it’s to provide comfort.
IE: I really hate the way this hamburger tastes … but you have to love the price.
The reason we so often default to efficiency is because efficiency is easier to measure. What would you say? Is selecting the right size equipment going to have a larger impact on efficiency or efficacy? Is locating supply vents closer to exterior walls going to have a larger impact on efficiency or efficacy? (I know there are a lot of variables … is the system a quarter ton too big or three tons too big.) Not really looking for an answer, just trying to provoke a little thought.
I would imagine that in the world of building performance professionals, Return On Investment is often a hard sell in simple terms of dollar and sense, based on efficiency alone. ROI in terms of efficacy is perhaps an even harder sell because it is more difficult … if not impossible … to quantify.
I have for years, run comparison numbers (for my area of the country) on the installation cost between different SEER equipment. ( The only cost difference being the equipment. ) The ROI on a base 13 SEER verses a 16 SEER is 10 to 12 years. Consequently we sell higher SEER equipment based on efficacy and not efficiency. Armed with the facts a surprising number of clients do choose efficacy even when they know there is little or no efficiency ROI.

By: Paul Raymer

Paul Raymer — Wed, 14 May 2014 18:54:19 +0000

Good job, Allison! Now what
Good job, Allison! Now what we have to do is relate cfm to health - maybe DALY/cfm?

By: kim shanahan

kim shanahan — Wed, 14 May 2014 18:50:20 +0000

This article certainly
This article certainly improved my efficacy: Useful information in - appearing smart out.

By: Mike MacFarland

Mike MacFarland — Wed, 14 May 2014 18:36:06 +0000

Nope, you don't sound smart.
Nope, you don't sound smart. People just assume you don't know how to pronounce efficiency correctly.

Always wondered about the difference in terms also- thanks!

By: George Blackburn

George Blackburn — Wed, 14 May 2014 18:02:31 +0000

Great thought and explanation
Great thought and explanation.