The answer to 'what size carbon monoxide detector do I need' is that the size of the carbon monoxide (CO) detector you need depends on the size of your home. As a general rule, you should have at least one CO detector on each floor of your home, including the basement. The detector should be placed within 15 feet of each bedroom. For larger homes, you may need additional detectors to ensure coverage throughout the living space.
CO detectors come in different sizes, ranging from small portable units to larger, hardwired models. The size you choose should be appropriate for the square footage of the area you want to monitor. Larger homes will require more powerful detectors to ensure they can pick up on dangerous CO levels. It's also important to choose a detector with a digital display that shows the current CO level, as this can help you identify potential issues more quickly.