Sub-Zero recently announced an overhaul of its line of built-in models, to be available this fall. What's especially interesting and appealing is that all the air in the line's models will be "scrubbed" by a purification system an average of once every 20 minutes to eliminate odors, viruses and bacteria that can lead to hastened ripening and, ultimately, spoilage. Additionally, the products offer something Sub-Zero states no refrigerator ever has -- a water filter that reduces viruses and bacteria, in theory reducing contaminants while keeping water and ice tasting fresh.

Other new features: brighter lighting, crisper drawers that have an improved glide system, an easy-to-use digital control panel and adjustable door shelves that can be moved in one-inch increments. The exterior can be customized, too, using one of these options:

• Flush Inset: Flush with surrounding cabinetry. Has a smaller profile and facilitates inset installation. Available in Classic Stainless, Platinum Stainless or Carbon Stainless Steel panels, or can be fitted with custom panels.
• Stainless Steel: Finished in Classic Stainless Steel, ready out-of-the-box. Works with any commercial-style kitchen. Redesigned with a new ventilation grille.
• Framed: Consumer may slide a custom cabinetry panel into an existing frame so that the door better matches the kitchen. Has a new extruded handle and redesigned louvered grilles.
• Overlay: Consumer may incorporate cabinet panels and custom handles into the doors and grille.

I have a Sub-Zero integrated model (similar to the model in the photo, a current Sub-Zero product) with an overlay that blends in so well that when the real estate agent was showing me the kitchen, I had to ask her where the refrigerator was. But buyer beware -- a Sub-Zero costs quite a lot, and definitely delivers on its promises, but can be expensive to repair. I learned this the hard way last year when my motor burned out because I hadn't "serviced" the system. Who knew a refrigerator required a yearly tune-up? It seems I have the Mercedes of refrigerators -- lovely to look at, performs like a dream, but even a simple oil change can set you back $300 (or, in my case, $1,000 for a new motor and yearly servicing).

Those who buy Sub-Zero appliances likely can afford any repair work on them, but why waste money? If you get one of these new models, be sure to ask the sales rep about yearly service.