Volvo's hot-climate facility tests its cars to the limit

By T. Uncle

SOMEWHERE out in the Nevada desert, where wind-blown tumbleweed ambles through the landscape and feathered, flightless roadrunners scuttle across the highways in a manner fascinatingly similar to their cartoon-screen equivalents, a collection of buildings circumnavigated by a network of sticky-hot bitumen roads wavers in the heat-haze.

This is where Swedish carmaker Volvo has invested significant amounts of money in building and maintaining a special hot- climate facility -- the sole purpose of which is to determine how capably Volvos will handle the rigors of being driven, day in and day out, in the hotter parts of world.

And not just the ability of the vehicle to withstand being subjected to unrelentingly searing temperatures: It also determines the ability of the car's systems to keep driver and passengers cool, comfortable and safe.

Volvo has done significant research into the effects hot climates have on driver safety, and has the data to prove that a cool driver is a more alert, responsive driver.

Thus a large part of the facility's function is to develop and test air-conditioning systems that maintain appropriate levels of driver -- and passenger -- comfort in hot climates.

The company has even gone to the extent of developing a special test dummy that records temperatures in various zones around the body.

Air-conditioning, today, is less of a luxury item than a necessary one.

In the demanding, high-volume traffic conditions of the 1990s, the need to remain alert is more important than ever.

Air-conditioning is common even in entry-level vehicles and has almost become an expectation on many standard-equipment lists.

And, despite the basic high-tech nature of most in-car air- conditioning systems, the levels of sophistication are on a constant upward curve.

In-car climate control, as opposed to conventional, straightforward air-conditioning that merely cools and dehumidifies the air, is a sophisticated, complex science.

It allows the maintaining of comfortable interior temperatures through automatic manipulation of heating and cooling systems, air-direction vents, fan speed and temperature control.

The driver simply "sets and forgets" the desired temperature on a dashboard control.

The systems are generally so complex that the subtleties are lost on the average driver.

The system on the new Saab 9-5, for example, actually lowers the relative temperature on the driver's side because the company has found drivers want -- and need -- a cooler flow of air than other passengers to maintain alertness.

The company has even developed ventilated front seats that draw hot air from underneath the driver and front-seat passenger to prevent the sweaty, sticky feeling that is an unfortunate side-effect of the leather trim used on most luxury cars.

However, it is the upper body that provides the most critical measure of how comfortable or uncomfortable you might be.

Volvo has found that it is more important to ensure a refreshing waft of cool air reaches passengers' faces than other parts of the body. If the face is cool and comfortable, the perception will be that the rest of the body is comfortable too.

The way the airflow is handled is also important.

Most automatic climate control systems quickly lower the interior temperature on hot days by turning the fan to maximum and recirculating interior air as soon as the engine is started.

By recirculating cooled air rather than constantly drawing in hot air from outside, the system works more efficiently.

When the temperature has reached the desired level, external air can be drawn in again.

Climate control is much more than air-conditioning.

Because it constantly monitors the interior temperature, subtly and constantly altering the mix of hot and cold air, it is able to maintain a required setting more accurately than any manually controlled system.

Some tips:

* When first entering a car that has been sitting in the heat for some time, open all windows to allow the superheated air to escape; the air inside a car sitting in the sun all day will always be significantly hotter than the air outside.

* Don't think that turning the climate control to maximum cool will bring the temperature down any quicker than simply leaving it on "automatic". The system's "brain" knows the quickest and best way to reach your comfort zone.

* By all means switch to recirculate when driving in heavy traffic, but allow the system to draw in fresh air as soon as the traffic clears. Most systems will draw in a certain amount of fresh air even when set on recirculate anyway.

* Most climate-control systems provide a quick-defog control that works to clear the windows when it is particularly cold outside by sending a rush of warm, dehumidified air to get rid of the condensation on the glass. It's usually noisy because the fan switches to the high setting, but use it.

* Adjustable vents should be used to send air up, not down, and towards the rear of the car. The cool air will circulate more effectively throughout the interior this way.