Evaporative Cooler
Cab Cooler Takes The Edge Off The Heat
Tom Berg
Equipment Editor
Shutting off the engine while waiting to load or unload eliminates fumes and saves fuel, but drivers won't do it when the weather's hot. They need mechanically driven air conditioning to avoid baking in their cabs. In recent years suppliers have introduced electrical or chemical coolers designed for sleeper compartments, but now there's a product that can work on daycabs, too.
The Viesa Master evaporative cooler, imported from Argentina, can take the edge off high temperatures, even with somewhat high humidity, according to a brief test we did in semi-arid Southern California heat. Viesa uses water vapor to bring down the temperature of air that's then blown into the cab. It may not replace A/C systems, but can keep cabs cool enough to avoid A/C use.
Indeed, Viesa is the only thing that scores of truckers in the Southwest now use, according to Daniel Acosta, who installs the product in and around Los Angeles. "Some guys buy it when the air conditioning in their trucks stops working and they can't afford to have it fixed," he says. "They can afford this because we sell it on payments, and they use it until they can get their A/C fixed."
Some truckers find Viesa helps even if their A/C works. "They'll use it when it's not so hot out and turn their A/C off, or they'll use both so they don't have to run their A/C so high, or they'll use it alone when they're climbing a hill so they can shut off their air conditioner and save the engine power," as well as avoid the loss of power when the engine fan comes on.
And truckers find it's their only alternative when anti-idling laws threaten hefty fines for running the truck's main engine. "We got mobbed after April by guys from Phoenix, who can't idle anymore," said Acosta, referring to that city's new anti-engine-idling ordinance meant to curb air pollution.
Acosta works for Viesa's American distributor, Safer Corp. of Anaheim, owned by investor Brian Moylan. They report sales of more than 400 units over the past two years, most of them to Latino truckers in the Los Angeles Basin, thanks in large part, Acosta said, to advertising in a Spanish-language trader publication.
The ads explain that a Viesa unit, mounted on the roof of a cab or sleeper, uses no engine power and burns no fuel. It uses varying amounts of tap water and its eight-speed fan draws from less than 1 ampere to as many as 8 amps from the truck's batteries. The plastic water tank holds up to 7.5 gallons, which will last from eight hours - enough for an overnight stay in extreme heat of a dry desert - to three days in more moderate conditions.
Acosta said he has installed Viesas on dump trucks as well as other daycab vehicles and sleeper-equipped tractors. A demonstration unit is mounted on the roof of the Isuzu NPR low-cabover that doubles as Acosta's installation vehicle. (The truck is also equipped with an automatic tire-pressure inflation system called Vigia, which Safer also imports.)
For my little test, Acosta drove the truck to Lake Elsinore, where it was 100 degrees Fahrenheit with humidity of about 55% - not beastly, but decidedly uncomfortable. On the way to Elsinore he said he had used only the Viesa, not the truck's A/C.
I asked him to park the truck facing west, with its cab headed into the early afternoon sun. He shut off the engine, rolled up the windows, leaving the driver's window open a crack, and set the Viesa's fan on high. We let the unit cope with the sun's cooking effect while we sipped some sodas at a nearby donut shop and he explained the ins and outs of installation.
It usually takes three hours to mount a unit, Acosta said. Installation includes cutting a hole measuring 20 by 40 centimeters, or 7.87 by 15.75 inches, into the roof, placing a thick rubber gasket and caulking it, and setting the unit squarely onto the seal. Sometimes he has to move marker lights and air horns to make a place for the unit. It weighs about 75 pounds, so a helper is required to lift and place the unit on the roof seal.
Acosta has trained a few dealer mechanics to install the Viesa, and owner Brian Moylan will send him to dealer and fleet shops to support volume deals. Moylan said a major truckload carrier plans to try 20 units in its ongoing efforts to cut down engine idling in its huge fleet. Company executives found him and the Viesa in his booth at the International Trucking Show in Las Vegas.
After a half-hour chat, we went back outside and I climbed into the Isuzu's cab and checked my old-fashioned mercury-tube thermometer that was resting in shade on the seat: Between 88 and 89 degrees, it said. Acosta had expected it to be lower, saying he'd put some ice in the water tank that morning. But even 11 or 12 degrees is a big difference on a hot day, and seemed enough to keep a driver from sweltering as he sat waiting in line, or to keep the cab inhabitable upon his return from lunch or a rest break. Without the cooler, it probably would've been 125 or so degrees in there.
"It works better when the air is dry," he said. "I've seen as low as 69 degrees (in the cab) up in Vegas when it was 110 outside, but really dry." Evaporative or "swamp" coolers don't work as well in high humidity, so Moylan figures his prime markets will be in the arid Southwest. Some Australian users who stopped at his booth at the Las Vegas truck show told him the Viesa works well with ice water on the hot, humid Gold Coast where they run, so he may do some testing in such climes.
A Viesa retails for $1,195 and should pay for itself in under 16 months if the user can cut his idling by 400 hours a year, Moylan said. He breaks that down to four hours a day for 20 days a month, based on $2 per gallon fuel. In California, diesel costs that and more, and a big engine uses about a gallon an hour when run at 1,000 rpm, where many guys set them. Like mileage, your savings - and the amount of reduced emissions - will vary. But it's one cool way to break the idling habit.
