Dahua NVR4232-EI NVR recorder 32 channels, 2 HDD bays, 1U, HDMI/VGA, AI

The NVR4232-EI accepts video from up to 32 IP cameras, so a single recorder can serve a larger building or several floors. Recording and live display are separate tasks: the unit decodes up to 16 streams at 1080p and 30 frames per second on screen at once, and adaptive decoding adjusts the display to the load. It also works with third-party network cameras, so existing cameras do not have to be replaced.

The recorder supports Smart H.265+, H.265, Smart H.264+, H.264 and MJPEG. The smart H.265+ and H.264+ codecs noticeably reduce recording size, so two hard drives hold a longer archive. Bandwidth for receiving, recording and forwarding video is 256 Mbps, dropping to 180 Mbps when the recorder's AI functions are enabled, which is worth considering when choosing the number of cameras and their resolution.

The recorder itself runs face detection and recognition on one channel (up to 10 face databases and 20,000 face images), perimeter protection on two channels and SMD Plus on four channels, which separates people from vehicles and so cuts the number of false alarms. With AI cameras, it also uses their face recognition, perimeter protection, SMD Plus, people counting, stereo analysis and heat maps.

The recorder is 1U high, measures 375 × 284.3 × 53 mm and weighs 1.51 kg. It can sit on a desk or go into a server rack next to other network equipment. It needs 12 V DC at 4 A and consumes just 10 W, which matters for a device running around the clock. An industrial-grade processor and an operating range of –10 to +55 °C allow installation in a utility room too.

A monitor connects through the HDMI or VGA output, so the picture can be watched at a security desk without a computer. Audio input and output allow sound to be recorded and played out, and four alarm inputs and two outputs link the recorder to door contacts or a siren, for example. It joins the network through an RJ-45 port, and Dahua states compliance with its security baseline 2.3.

Businesses, schools, retail and office buildings with more than 16 and up to 32 cameras; property managers who want to bring existing cameras from different brands into one recorder; and IT teams and installers who prefer a rack-mountable 1U device with low power draw and built-in analytics.