Which infrared (IR) sensor is considered best for a set-back box (SBB) due to its low cost and discreet appearance?

The best choice for a set-back box (SBB) is the prism sensor. This is primarily due to its low cost and discreet appearance, which align perfectly with the requirements for a residential or commercial setting where aesthetics and budget concerns are paramount. Prism sensors are designed to be unobtrusive and blend with various environments while still providing effective infrared detection.

Additionally, the functionality of prism sensors enables effective motion detection and thermal sensing without the bulk or prominence of other sensor types. This not only maintains the look of the installation but also allows for versatile placement options that can enhance overall efficiency in heating, ventilation, and air conditioning (HVAC) systems.

In contrast, standard IR sensors, while common, may not offer the same discreet aesthetic or advanced features that prism sensors provide. High-performance IR sensors typically come at a higher cost and may not be necessary for basic applications like those the SBB would serve. IR blasters, designed primarily for remote control applications, do not suit the sensing requirements of an SBB setup, focusing instead on transmitting signals rather than detecting them accurately in the same manner as a motion or presence sensor would.