Product Review: Acrylic Greenhouse Glazing
Now that winter is over and heating bills are in hand, it is easy to see the effect of rising energy costs on your business — it also is easy to see that something must be done to help lower those costs in the future. Improving your greenhouse with a new covering such as Degussa Cyro's Deglas acrylic glazing just may do the trick. In addition to its other qualities, growers I spoke with believe it noticeably saves on energy costs.
Deglas acrylic is a roof, perimeter wall or interior partition wall glazing material available in three styles: 16-mm Alltop standard, 16- or 8-mm Deglas High Impact and 11Ú2-mm Deglas Corrugated High Impact. The High Impact acrylic styles have a non-prorated, 10-year warranty on light transmission and hail impact.
Deglas acrylics are available in lengths ranging from 4 to 36 ft. All double-skinned acrylic comes in widths of 471Ú4 inches; Corrugated High Impact acrylic is 41 inches wide.
The 11Ú2-mm corrugated and 8-mm acrylic products are designed to be point fastened without pre-drilling. The High Impact acrylic can be installed in curved applications with a radius ranging from 108 to 48 inches.
The acrylic is designed to resist hail impact, transmit light and last for years. In fact, most growers I spoke with cited these qualities among their favorites, along with energy savings.
Pat Etzel, director of facilities and greenhouse systems at Len Busch Roses, Plymouth, Minn., appreciates the durability and longevity of Deglas acrylic. Len Busch Roses first installed acrylic in 1979, and Etzel pointed out the original pieces look as good as the most recent acrylic construction installed in 2003. "It is very long term," he said. "Our experience has been with some material that is 25+ years old. It is there for the long haul." Most of the other growers I spoke with have had similar experiences. They still use acrylic they installed in the early to mid-1980s.
The high-impact acrylic, introduced in 1999, is designed to be more durable than the original version. Mark De Jong of De Jong Greenhouses, Pella, Iowa, described the orginal acrylic's susceptibility to hail: "With acrylic, you're probably going to have a hole in one layer, unless it is really, really nasty hail, and then it might punch all the way through."
The new high-impact version is more hail resistant. According to the manufacturer, it can resist up to one joule of energy, which is roughly the equivalent of a 1-inch piece of hail. "They have a high-impact product now that basically takes the hail concern out," explained De Jong. Tim Raker, vice president of C. Raker and Sons in Litchfield, Mich., agrees. He feels the new acrylic formula withstands hail very well, more so than the original version.
Light transmission for Deglas acrylics is engineered to remain within 4 percent of its original capabilities. The manufacturer has tested its light transmittance at 84-91 percent initially, and 81-88 percent after 10 years. Percentages depend on the type of acrylic used.
"On low-light days, the acrylic tends to capture what wavelength is out there," said Raker, "and when it comes through the acrylic, it actually gets magnified. I don't know to what degree, but it's noticeable to me." De Jong feels the acrylic's light quality is similar to glass, and he likes that it doesn't yellow over time.
Energy savings range from 40 to 70 percent over alternative single-layer coverings, and growers who have acrylic have noticed the difference. De Jong described the savings as huge. "This is easily a 50-percent savings we feel," confirmed Etzel.
Raker uses an energy curtain with his acrylic to improve heat retention even further. "It makes our system that much better because we've got the twin-wall acrylic and the energy curtainÉwe've got an extra barrier in there," he said. The glazing's double layers provide insulation. Though, Raker finds the acrylic retains heat so well, snow has a tendency to stick on the roof until the sun warms it and it slides off.
The energy savings of Deglas acrylic can help offset the initial cost, and not having to frequently replace the covering can help save money in the long run. De Jong found sometimes paying more upfront is beneficial in the long run. "It becomes a matter of the time value of money, really," he said.
Even though acrylic costs more initially, Etzel feels it is a worthwhile purchase for those in the green industry: "I think it's very much a product that fits the needs of growers today in terms of energy efficiency, high light transmission and low maintenance. It's a long-term investmentÉbut I think it's one of the easiest materials to grow under."