Smart Building

Indoor vs. Outdoor Cables – Which Should You Choose?

Michael Bodzay

In the telecommunications world, it’s understood that outdoor applications call for outdoor (OSP) cable to maintain performance levels. But what about other types of cables, such as security or control cables? What are the guidelines? When should you use indoor vs. outdoor cables? Let’s take a look at a few recent situations we’ve encountered and see whether indoor or outdoor cable should have been used.

Situation No. 1: Sports Stadium

As a project moves forward, it’s inevitable that plans change – and these changes can impact equipment location (and, as a result, cable location).


During a recent stadium buildout, a particular piece of equipment ended up being relocated. Instead of installing it inside, the equipment would be installed outdoors underneath an adjacent parking structure.


The area was sheltered, but there was no climate control – so the Digital Electricity™ Cables that connected the equipment to the network would be exposed to the area’s high humidity levels and temperature fluctuations. In this location, the cable would, however, be protected from rain and wind.


Does this situation require indoor or outdoor cable? The answer: Outdoor cable! Just because the location offers protection from wind and moisture doesn’t mean the cable can withstand high humidity levels or temperature fluctuations.


Fortunately, our partners on this project brought the change to our attention and we were able to provide our recommendations before it was too late.


Situation No. 2: Bridge Construction

During construction in Canada, a control cable was being installed underneath a bridge. Similar to Situation No. 1, the cable in this case would be protected from the elements – but it would be exposed to temperature fluctuations and humidity.


In this case, however, the humidity levels were lower than in Situation No. 1. Outdoor temperatures would be lower most of the time as well, but fluctuations would still occur. The cable would be protected from snow and ice buildup.


Does this situation require indoor or outdoor cable? The answer: Outdoor cable! Just because it’s being installed in a sheltered location with lower temperatures and humidity levels doesn’t mean the cable can withstand weather fluctuations or extremes.


In fact, the outdoor temperature dipped to near -4 degrees F during this project. The cable being used had a minimum installation temperature of between 25 and 32 degrees F. Due to these conditions, the cable became brittle and started cracking during installation, so it could no longer be used.


When to Use Indoor vs. Outdoor Cable

Even if it’s being installed in conduit, no matter what kind of cable you’re using – whether it’s fiber, copper, security, control or another type – you should always use an outdoor-rated version of that cable whenever it will be exposed to one or more of the following:

  • Condensation
  • Humidity
  • Moisture
  • Sunlight
  • Unregulated temperatures

There will likely be a cost difference for outdoor cable, depending on the type of cable you choose. The cost often depends on the protection measures taken.


With many security cables, for example, a water-blocking tape is wrapped around the corded cable before the jacket is put on it. Even if water gets through the jacket, it won’t be able to permeate the tape barrier. The core – where all the conductors are located – remains protected.


Other cables are filled with water-repelling gel that fills the gaps within the cable’s internal conductors. An outer jacket is then applied; migration of water into the cable becomes very difficult.


Thicker, more resistant outer jackets are also used to protect cable from environmental elements.


Have questions about using indoor vs. outdoor cable in your next project? We’ll help you decide!