Portable heating and ac is getting more popular as a niche for many hvac service companies.

Now that we have lived through the first winter, spring and summer of the 21st century, let's consider the state of heating and cooling tents used for special events year-round.

Why suffer? Why stage an event that most will likely remember only for its discomfort? "Remember the August wedding where the bride's sweat soaked through her great-grandmother's wedding gown?" Or perhaps, "Remember the November trade show where the vendors sold all the promotional sweatshirts the first morning because the tent was so frigid?" Or "Remember the company party where the heater fan blew off the president's toupee?"

Our economy is strong, science is advancing, and continued progress is expected in many areas of life - including tented events. It may no longer be true that, "if you erect it, they will come." They may ask first, "Is it going to be air-conditioned?"

As Jody Acre, sales manager for L.B. White Company, Onalaska, Wis.., says, "People have realized that tents aren't about roughing it. They're learning that you can have an elegant affair in a tent." L.B. White is a major supplier of temporary heating equipment.

Ken Cannella, product manager at Temp-Air Rental Services, Burnsville, Minn., observes that corporations that are shelling out tens of thousands of dollars - and more - to host special events don't want them to be ruined by the weather. "There's going to be a tremendous amount of growth (in this market)," Cannella predicts. "People want to stay comfortable at 70 to 758." But Temp-Air has both cooling and heating divisions, and the growth may not be equally divided between them. Currently, he says, making special-event tents comfortable constitutes "about 25% of our business overall."

A pricey option?

Some consider climate control to be a pricey option. Jim Gallagher, owner and president of Partytime Productions near Chicago, said that because air conditioning is "the largest line item on a proposal, by three times, we don't provide it in-house. Only 5% (of tent renters) get air conditioning." But, Gallagher says, "the weather is a crapshoot," especially in the Midwest. "We set up a week to 10 days before an event, and we can't know what the weather will be." Some people get ac for peace of mind, "but it's a costly peace of mind if they don't end up needing it. Ninety-five percent say no, we'll take our chances."

The numbers were similar at Abbey Event Services, Burbank, Calif., says general manager Tom Gifford. "My wild guess is that probably 10% choose to use air conditioning. It's expensive. Some will use evaporative coolers or misters or fans." Gifford also says, however, that "more than once" a customer has balked at air conditioning only to recant after the event, admitting that they wished they had gotten it. With Hollywood production studios nearby, notorious for hot stage lights, the market for portable ac is such that it can be obtained on short notice. "There were a few events this past year where we advised people that they get it, they insisted they didn't need to, and the day of the event they changed their minds and we were able to get companies that could turn it around fast."

Even in sunny California, Gifford notes, "It does rain and get cold in winter." He estimates that 90% of rented tents use heat in the winter months. "Here, if it's 508, people are freezing. But most of the time, the heaters are shut off right after the guests arrive. That's enough for the duration of the event."

Cost may be one acceptance factor, according to Tina Behnke, vice president of sales with AirPac Inc., a Front Royal, Va., ac manufacturer. In addition, she says, "Rental air conditioning just hasn't been around that long." If you take that into account, current usage is not so low. And once it's "been around" a while longer, people may forget it was ever optional.

According to Behnke, "This past year our tent business has probably doubled; it has been crazy. We had a big container shipment that went to Europe. Air conditioning is fairly new to the tent industry. It used to be a luxury, but now it is a necessity."

Where it isn't a necessity, ac can be a selling point. Temp-Air's Cannella says that, in addition to providing tent climate control for international automobile product launches and the Special Olympics, his company cools merchandise tents at golf tournaments. "An air-conditioned tent attracts people," he says, "and then they buy merchandise. If you get people to spend more time in your tent because it's cool, people buy more. You do see a jump in sales."

In the past, both heating and air conditioning in tents was imprecise at best. Now, most equipment makers have detailed sizing charts that tell planners how many units of equipment of what size and power to place in various locations inside and outside the tent.

According to Tina Behnke of AirPac, "In homes, you need about one ton of air conditioning for every 4,000 square feet. In tents, you need one ton for every 150 to 250 square feet, the range being for what people are doing in the tent and what time of day the event is held. In the middle of the day on a black asphalt parking lot? Then probably 150. On a grassy cliff overlooking the ocean at eight in the evening? Probably 250."

And now, even portable equipment comes with modular ducting, directional nozzles, quiet blowers, and remote-control thermostats. Customer feedback leads to improved design, too. At AirPac, customers suggested - and got - recessed carrying handles for easier storage in off seasons, and the newest product, the TentAIR, which is a trailer-mounted ac unit for "big, festival-type events." At L.B. White, customers at the Super Bowl requested a rocker switch for converting from heat to air circulation during warm parts of the day.

Features such as ducting are no longer uniform. L.B. White offers "slinky-type" ducting that collapses to three feet or expands to 12 and that fits a register on its end with a quiet "squirrel cage" fan. "Often, forced air has a bladed fan," Jody Acre says, "and it makes noise. But we could have a conversation in a tent sitting right next to the heater."

AirPac's ducting is pure polypropylene fabric, with no supporting skeleton. "It's really bright and slick, and it comes in 20-foot sections that zip together," Behnke says. "It blows up and stays up against the contour of the tent, and its diffuser holes are distributed every few inches for more even and quieter air flow."