IT WAS an exhibition at the National Building Museum that made me realize there's something about air conditioning I love . . . but just don't trust.

Like the technology it celebrates, the "Stay Cool! Air Conditioning America" show now at the museum is a thing so seductive and chilling -- in both the literal and the figurative sense of the word -- that it occurred to me there has to be something evil about this engineering marvel, besides the consumption of fossil fuel, the destruction of the ozone, the homogenizing of regional cultural differences and the encroachment of development into previously inhospitable wilderness.

Maybe Ted Kaczynski had a point. After all, what hath this scourge/godsend of the post-World War II appliance world wrought, besides such atrocities as Las Vegas, wall-to-wall white shag carpeting, enclosed malls and the death of the front porch? Well, Mr. Goodbar and the new album from Britney Spears, to name but two of its many benefits.

But I'm getting ahead of myself.

When I visited "Stay Cool" in early June, the temperature hovered just shy of 100 degrees. An angry, midday sun beat mercilessly on the sidewalks of the city and on my perspiration-drenched nape.

Relief was palpable and immediate as I stepped through the exhibit's glass doors into a larger-than-life-size mock-up of a sheet-metal air conditioning duct. Without air actually rushing through it, it was little more than a cool stage set, yet I felt suddenly cool -- like Tom Cruise or Robert Redford sneaking through one of those man-sized ventilation shafts that seem to exist only in Hollywood thrillers.

From a distance came the white noise of a fan in one of three facsimiles of cooling towers. Mounted in the sides of these towers (which helpfully illustrate the difference between galvanized, galvanneal and polyvinyl chloride duct material!), video monitors continually retold the story of refrigeration science: how pressurized liquid coolant in coils is allowed to expand, thereby removing heat from the surrounding air as it warms up. Despite the overheated techno-speak of the wall text (who really cares about elastomer butyl gaskets anyway, as long as it's cold?), something about the numbingly lovely sound of the room itself was enough to lower my psychological thermostat. I didn't want to leave this climate-controlled womb.

That great Satan, Freon, had claimed another victim.

Now don't get me wrong. I love air conditioning as much as the next guy. I slept in an air conditioned room last night and I'm typing this in an air conditioned building. My car is equipped with air and, as a life-long Washingtonian, I like nothing better than to sit in a darkened movie theater in August with the A/C cranked so high I need to wear a sweater.

I am a child of air conditioning and I am not about to go live in a cabin in Montana without my high-tech gadgets. The Building Museum's musty display of pre-A/C cooling apparatuses (genteel hand-held fans and inefficient-looking electric models from the early years of this century) were enough to convince me of that.

And yet . . . and yet . . . why does this exhibition feel less like a history of technological progress and social change than an advertisement for something whose myriad benefits are already manifest, in fact something that's pretty much taken for granted?

Maybe it's the commercials for air conditioning from the 1950s, '60s and '70s playing in a videotape loop on a vintage TV placed in front of a comfy, retro-looking sofa. Or maybe it's because one entire wall is covered with print ads and archival photos of suave and debonair people standing in front of sleek window units. Could it be because the exhibit was sponsored by the American Society of Heating, Refrigerating and Air-Conditioning Engineers and the Air-Conditioning and Refrigeration Institute?

I don't think so. There's something more subtle and insidious going on than the mere pushing of an appliance. After all, as "Stay Cool!" demonstrates, with the technology's promise of creature comfort and convenience, air conditioning sells itself. Without the so-called "process cooling" of industry (which has actually been around in some factories since the late 19th century), we would have to give up our computers, music CDs and many medicines, not to mention the uniformly high-quality pasta, rubber bands, toothpaste and chocolate we have become accustomed to.

All of these products, we learn here, require air conditioning in order to avoid contamination and manufacturing defects. Who wants to eat a gray candy bar? That's what happens to the color of chocolate when it's allowed to cool in a room warmer than a certain temperature.

What's really frightening though is our drug-like dependence on this beast, and the contemplation of what exactly our society has lost by gaining dominion over the weather.

Neither of these philosophical issues are adequately addressed here, except in a few ironic quotations posted on the wall. In 1981, writer Fred Hobson speculated (perhaps tongue-in-cheek) that the rise of air conditioning may be responsible for the "decline of the creative fury of the Southern writer." And in 1979, Frank Trippett lamented in Time magazine about air conditioning "all but obsoleting the front-porch society whose open casual folkways were an appealing hallmark of a sweatier America."

Few of us seriously want to sweat more, but maybe, just maybe, there are still a handful of us who are able -- while basking in the luxury of our air-conditioned homes and offices -- to wax nostalgic for the sense of community and natural connectedness that have been sacrificed in the name of progress. "Stay Cool!" only hints at that, but its obvious that there's no turning back.

At the National Building Museum, there's a bank of telephones where you can listen to recorded testimonials about air conditioning (as though that's necessary). There's also a demo version of a CD-ROM "Thermal Comfort Tool," a computerized model designed to help engineers understand the variables that affect physical comfort. In a delicious but unintended irony, neither was working during a recent visit.

Which only serves as a reminder of that sense of desperation that constantly lurks just below the surfaces of our psyches, hoping and praying that the electricity doesn't conk out.

STAY COOL! AIR CONDITIONING AMERICA -- Through Jan. 2, 2000 at the National Building Museum, 401 F St. NW (Metro: Judiciary Square). 202/272-2448. Open Mondays through Saturdays 10 to 5; Sundays noon to 5. Free admission. Web site: www.nbm.org.

CAPTION: A circa 1955 air conditioner ad stresses cool elegance.

CAPTION: A 1954 brochure promotes the wonders of climate control.