Efficiency, Fact and Fiction
Written by Al Zylstra 
Sustainable, Green, Energy Saving, High Efficiency…all terms that grab our attention these days, as they should. Greenhouse operators need to keep up on investments in efficiency as energy costs rise, just to keep those costs in line with revenues. But just like the last energy price run-up, and the ones before that, the efficiencies and resulting savings claims often invite further scrutiny, and they should. Most efficiency related investments still have compelling merit even with actual un-inflated efficiency claims. It will pay to sift through those claims, carefully, you will save money either way.
So, if you invest in a greenhouse curtain system that “saves 40%”, and that new fangled heat mat that “uses 30% less energy”, and it is powered by a new “99.8% efficient” boiler, and the newest greenhouse covering that “cuts heat loss by 25%”, does that mean your greenhouse eventually will no longer need heat? Or, maybe the gas company will send you a check every month…hey, I like that deal, get me two!
One of my favorites is the “99.8% efficient” boiler for heating. Does it really exist? Well, sort of. A boiler that can operate at 99.8% efficiency really exists, it just doesn’t happen to be 99.8% efficient when used to heat your greenhouse. Then it is more like 89 to 94% efficient, depending on the type of heat delivery. That’s still good, and may be worth the investment, just not as dazzling. So, you gotta ask the question: “will it be that efficient in my facility, in this application and these temperatures?”
And, be cautious of claims about how bad your existing equipment may be. I recently heard from a grower that was told his boiler “lost 3-5% efficiency, every year”. My oh my, that would be very bad! Maybe in one year, if it isn’t maintained properly, but not every year. But it sure made a new boiler sound better.
So, don’t be shy about asking those hard questions of the person working hard to compel you to invest in a more efficient product or system. They are probably telling the truth, just make sure you get the facts that apply to your facility and your application. Facts often are at least as good as fiction.