At some point in your business, or private residence, you will feel the need to enhance security, and this means installing a surveillance system. While shopping around for this system, you will come across two most popular options: DVR (Digital Video Recorder) and NVR (Network Video Recorder).
From the time you decide which system to go with, one thing has to be clear: that the option you choose will have great impact on the total cost, quality and overall retention of footage. In this case, it all comes down to cost vs quality and value for money.
In this post, I will assist you in understanding the similarities, differences, pros and cons of DVR and NVR system. This includes:
- Comprehensive information on how DVR and NVR systems work
- The advantages and disadvantages of DVR vs NVR systems
As you can see, I’ve focused on the two major options. However, there is a third option- cloud camera system. This will be covered in the next article.
There also exists another option- Analog HD. This, too, I will cover in a separate article.
DVR vs NVR- The Differences
Put bluntly, a DVR system records and converts analogue footage into digital format while NVR only works with digital footage. To put this into context, in an NVR system, the footage is recorded and transmitted raw, in an analogue format. The conversion to the digital format is done in the DVR (Digital Video Recorder). However, in an NVR system, the footage is recorded and converted into a digital format right there by the camera and then transmitted to the NVR (Network Video Recorder).
From the way the footage is captured and transmitted, a DVR system mainly uses analogue cameras.
Since in an NVR system the footage is captured in a digital format, an IP (Internet Protocol) cameras are used. These transfer the processed stream to the recorder via an ethernet cable.
The table below outlines the main pros and cons of the DVS vs NVR systems.
| DVR | NVR | |
|---|---|---|
| Name | Digital Video Recorder | Network Video Recorder |
| Camera Type | Analogue Cameras | IP (Internet Protocol) cameras |
| Transmission | Coaxial cables | Ethernet Cables or Wirelessly (WiFi) |
| Video Processing | At the recorder | Within the camera |
| Recording | Video only | Audio and video |
| Video Quality | Low resolution | Higher Resolution |
How a DVR System Works
This system is designed to record CCTV footage in a digital format. As mentioned above, the footage is captured and transmitted in an analogue format. The recorder then converts it to a digital format for storage and streaming. The technical details on how this happens is beyond the scope of this article and thus will not be covered.
Hardware
- DVR Recorder
- Analogue CCTV Camera
- Coaxial Cables
- Storage Unit (usually hard drive)
- Display Unit (monitor)
How an NVR System Works
A Network Video Recorder system records and converts CCTV footage into a digital format right in the camera and then transmits this footage to a recording device or directly to a live stream. The transmission is carried out via an ethernet cable or wirelessly via Wireless Fidelity (WiFi).
In a wired transmission of the footage via an ethernet cable, a POE (power over ethernet) cable is connected directly to the recorder. This cable both powers the camera and transmits the footage as well. Due to data and power loss over distances, the farthest distance is usually restrictive to within 100m (in a scenario where repeaters are absent).
For a wireless transmission, the IP camera is connected to a power source, and the video footage is transmitted via a WiFi network.
Hardware
- NVR Recorder
- Wireless IP Camera
- POE IP (Power Over Ethernet) cameras
- Ethernet Cables
- Display Unit (Monitor)
Pros and Cons of the Two Systems
NVR- Pros
Video Quality: a higher video resolution is offered by IP Cameras. The typical quality is between 2MP (1080p) and 12MP(4K). The frame rate is about 30 fps for the real-time video. When streaming live, the video quality can be adjusted accordingly.
Installation: it is easier to set up the ethernet cables, each for a camera, as compared to the coaxial cables, which are required by the DVR system.
Camera location flexibility: this mainly applies to wireless cameras. Cameras can be placed in locations where wiring would be a challenge, especially outside.
Audio: ethernet can transmit audio, thus allowing each camera to deliver an audio stream to the recording device or livestream.
Connected to the network: this allows for remote access to the footage. If you are within the same network as the camera system, you do not even need an internet connection in order to access the footage. It can be accessed from anywhere within the locality of the camera installation, as compared to going physically to the display unit to view.
Security: the footage is encrypted, so access to it is restricted to authorized personnel only.
NVR- Cons
Network security challenges: since NVR systems rely on network connection, this can pause a serious security risk. If your network is not secure enough, hackers can penetrate and thus compromise the system.
Compatibility: cameras have to be purchased that are from the same manufacturer. For example, you cannot use Hikvision cameras with Dahua NVR.
Cost: it is quite expensive to set acquire and set an NVR-based surveillance system.
Durability: an NVR system usually lasts between 4-8 years. Some components, like storage hard drives, last even less.
DVR- Pros
Cost: in a nutshell, since this system is not as advanced as the NVR system, it tends to cost relatively less.
Camera interoperability: a DVR system allows the use of cameras from different manufacturers within the the same device.
DVR- Cons
Running cables: each camera requires two cables- one for power and the other for video footage transmission. This often causes cable clutter.
Video quality: due to the limited bandwidth of the coaxial cables, video is of lower quality as compared to NVR system.
Limited audio capabilities: the farthest distance that a camera has to be placed from the DVR recorder is limited due to signal degradation since an RCA cable is required for audio transmission, unless repeaters are added.
Limited supply: as technology makes huge leaps forward, fewer and fewer manufacturers are willing to continue producing this outdated technology. In the end, you will incur higher maintenance costs.
Summary
From the information that I have provided above, you can see that even though an NVR system is costly to set up, the overall pros much outnumber the cons.
Disclaimer: the use of brand names in this article does not mean an endorsement. They are used solely for the purpose of illustration and information. But, whichever system you choose, it is good to understand the context under which you are choosing it, your budget, and overall scale of the project.
