Under-the-cabinet microwaves are also called over-the-range appliances, because of the placement over stoves and cooktops. This is generally the key difference between under-the-cabinet and built-in microwaves. However, both microwave types can involve using the cabinets and the walls in your kitchen. Still, how a built-in model uses the cabinet is different from over-the-range models. These two types of microwaves, as well as countertop models, generally use the same heating technology, though some high-tech models use advanced features, such as convection cooking. As you compare built-in and under-the-range microwaves, you will see that many of the differences are mostly external factors.
Built-in microwaves sit inside the kitchen wall or inside a custom cabinet and generally serve the singular function of heating food. Under-the-cabinet microwaves commonly have extra components that complement the range or cooktop below, independent of microwave cooking. The only part of the built-in microwave that shows to the public is the front door, because its sides, top and back are recessed into the wall. For this reason, some built-in microwaves may not have outer surfaces that are painted with a fancy color or have a stainless steel finish. The outer frame of under-the-cabinet microwaves is also hidden away, but the underside of the unit is usually painted and finished because a person of short stature can easily view this area.
Ventilation Hood and Lighting
Ventilation fans are almost mandatory in under-the-cabinet microwaves because of the common placement above a range. Built-in microwaves do not generally feature vent hoods because even the underside is hidden and blocked from view. The immediate benefit of these hoods is that you can control and redirect steam and smoke that rises from hot pots and pans below. This lessens moisture, soot and odor buildup not only the range, but on your immediate kitchen wall as well as the microwave. The placement of the microwave over the range is a valuable space saver in homes with smaller kitchens. Also, many vent hoods include simple, but necessary incandescent lighting for use while cooking on the range.
Built-in microwaves can require major initial planning and customization of your kitchen, especially if it is to rest inside a wall. Under-the-cabinet microwaves can also necessitate planning, but usually the microwave matches the length of the range below, and both just slide into place in many modern kitchens. In many instances, a built-in microwave rests above a built-in wall oven and built-in warmer drawer, all vertically aligned. Professional installation is indicated for both microwave types, but built-in microwaves can cost more, especially if you need an electrician to create more outlets inside the wall.
Clearance and Spacing
Both built-in and under-the-cabinet microwaves have clearance and space requirements to ensure the proper function of the unit inside and out. However, for built-in models, the installation can grow increasingly complex the nearer it is to other appliances in and along the wall. For example, if the built-in microwave rests between a side-by-side refrigerator on the left and a range on the right, then doors from one appliance can strike and blemish or damage other appliances because of improper spacing. The main clearance concern with under-the-cabinet microwaves is making sure it's not too low, making range-cooking uncomfortable and also to catch smoke and steam before these gases escape into the rest of your home. Some built-in microwaves feature drop-down doors instead of side-opening doors.