Microwave Review

Evaluating microwave performance and reliability

Today's microwaves fall in three main categories: countertop, over-the-range (also called microhoods) and built-in models. Our report focuses on countertop and over-the-range microwaves, which can be added to any kitchen. We do not cover built-in microwaves in this report as they usually require customized installation and are added to a kitchen only during a major remodel.

Countertop microwaves are available in a variety of sizes, from compact units as small as 0.5 cubic feet, appropriate for apartments and dorm rooms, to more spacious full-size 2.2-cubic-foot microwave ovens that can accommodate 9-by-13-inch baking pans. These microwaves don't require any installation; they're plugged into a standard outlet. Full-size countertop models generally run in the $150 to $350 range and offer 1,100 to 1,300 watts of cooking power. Compact microwave ovens are cheaper, often costing less than $100, but they also possess weaker cooking power -- around 800 watts -- which makes for longer cooking times. Some countertop microwaves can also be installed under a cabinet with an optional hanging kit, or installed as built-ins with an optional trim kit (typically between $100 to $150).

Over-the-range microwaves (also called microhoods) can cost anywhere from $200 to $1,200. In addition, they often require professional installation, which adds to their total cost. As their name suggests, these units are designed to be mounted over a range, so they include extra vents to move heat away from the stove. Most models are designed to fit into a 30-inch-wide space -- the common width of a range -- and capacities vary from 1.1 to 2 cubic feet. Both countertop and over-the-range microwaves typically come with a one-year warranty, although many brands provide lengthier coverage for the magnetron (the tube that produces microwave energy). In general, over-the-range microwaves receive fewer reviews than countertop models, perhaps due to their more invasive installation.

There have been several new developments in microwave technology in the last few years. Perhaps the most useful is the addition of cooking sensors, which measure the humidity in a microwave and then automatically adjust cooking times to prevent overcooking. Expert and user reviews indicate that this feature works well on most microwaves, although we did run into occasional complaints about liquids overheating on the sensor setting. Inverter technology is another optional feature. Unlike standard microwaves, which cycle between periods of 100 percent power and no heat, a microwave with inverter technology can run continuously at half power, which results in more even cooking. While users say this feature does work, we found plenty of good reviews for microwaves without inverter technology. None of our top-rated models includes an inverter.

One of the most advanced additions to microwave ovens is a convection mode. Convection microwave ovens circulate hot air throughout the oven, a process that promotes more even cooking and surface browning -- normally a weak spot for microwaves. Convection microwaves can bake cakes, roast chickens and grill burgers, although experts say they usually can't do any of these jobs as well as a standard oven. Moreover, a convection feature can add significantly to the price of a microwave, so if you mainly want to reheat and defrost foods, a standard microwave will be more cost effective. Top-rated microwave ovens usually cost $100 to $200 less than comparably sized convection microwaves.

The latest addition to microwaves is the steam function. With this feature, you fill a reservoir with water and as it evaporates, it steams your food. Steam can help heat penetrate the food and also add moisture to food without increasing its fat content. However, at present this feature appears only on higher-end microwaves. Only one of the microwaves covered in our report -- the over-the-range Whirlpool GH7208XR (*Est. $875) -- includes a steam function.

Overall, ConsumerReports.org offers the most credible microwave reviews and testing. On its website, the organization prints test results for 80 countertop and over-the-range microwaves, rating each on heating evenness, noise, auto-defrost and ease of use. Good Housekeeping magazine editors have also tested 22 microwaves by reheating leftovers, baking potatoes, defrosting ground beef and popping popcorn. They recommend six microwaves, but they do not outline their criteria, and there is no direct comparison among the models. We also found reviews for one specific microwave model in Wired magazine and the technology blog Unplggd.com. To supplement the professional reviews we found, we also looked at user reviews at ABT.com, Amazon.com and Sears.com, as well as user-review sites such as Epinions.com and Viewpoints.com. We found the feedback from users helpful for gauging long-term reliability.