When shopping for an DVR, you’ve probably seen terms like 16-Channel DVR or 8-Channel DVR being thrown about. Same when shopping for an NVR; 16 Channel NVR’s are popular, as are 32 NVR’s. There’s some confusion as to what the term channel means, and how many security cameras they actually accommodate. What’s the difference, and how many do you really need? Is it different for DVR’s than it is for NVR’s? Keep reading to find out.
Explaining DVR Channels
DVR channels are really quite simple; since they work with analog CCTV systems, each security camera requires its own cable, which must be plugged into its own port on the DVR. Each port corresponds to a channel.Thus, a 16-channel DVR can handle 16 security cameras, an 8-channel can handle 8 security cameras, and so on. The number of cameras cannot really be separated from the number of channels the device can handle.
Explaining NVR Channels
While DVR’s can only support as many security cameras as it has channel ports on the back, things are a bit different with an NVR. Thanks to Power-over-Ethernet, it is actually possible on some models to connect more security cameras than the number of ports on the back of the NVR, using a PoE switch. A PoE switch lets you use more than one security camera into a single port, supplying power and combining both signals into a single Ethernet cable that runs back to the NVR port. In most cases, you can easily double the number of security cameras available to your NVR.
But, while you are not necessarily limited by the number of ports on the back of the DVR, you are limited by the channels dictated by the NVR firmware; your NVR might have 8 ports but be able to accommodate 16 channels, simply recognizing the two multiple signals on a single cable as the two distinct security cameras they are. On the other hand, it might be limited to merely 8 channels with those 8 ports. It depends on the exact model you’ve selected for your CCTV system.
How Many Channels Do You Need?
The exact number of channels you need depends on how many security cameras you have and how many you foresee needing to install to proper coverage. Smaller businesses will likely be fine with an 8 or 16-Channel DVR or NVR, but larger facilities (such as warehouses) will probably need a 32-channel (or more) to accommodate the necessary number of security cameras. In that case, you’ll likely need an NVR and IP system to accommodate the sheer scale of the system. You might also be able to cut down on the number of cameras installed with PTZ cameras, for example.
If you’re just getting started with a few cameras but plan on expanding your system at any time in the foreseeable future, you might as well go with a 16 or 32-channel device and be prepared for adding cameras when the time comes.