The question of whether to use shielded or unshielded cables often arises when it comes to such projects as the wiring of a home office, the fitting-out of a commercial building, or the upgrading of industrial equipment.
When you glance at shielded cables and then their unshielded counterparts, you might barely discern any visual difference between them. However, the similar appearances of these cable types bely a potentially significant gap in performance, particularly in settings where electrical interference may be an issue.
In this guide, then, we’ll take a closer look at both shielded and unshielded cables. Along the way, we’ll address the specific circumstances in which each type typically performs best, as well as other aspects that installers, businesses, and homeowners should think about before they decide on the specific cable to use.
The Basics of Shielded Versus Unshielded Cables
A good way to summarise the distinctions between these two options is that unshielded cables are the standard for most domestic setups, whereas shielded variants are often preferred for high-performance or high-interference environments.
However, there are various other useful things to know about them:
- Unshielded cables are commonly referred to as Unshielded Twisted Pair (UTP) cables in networking. Such cables contain pairs of twisted wires without any additional metallic shielding around them. This twisting helps drive down interference naturally, which makes them sufficient for a multitude of everyday applications.
- Shielded cables are frequently known in networking contexts as Shielded Twisted Pair (STP), Foiled Twisted Pair (FTP), or S/FTP cables. These cables incorporate additional layers of metal foil or braided mesh around the wires. This provides a further barrier against external electromagnetic interference (EMI) and radio frequency interference (RFI).
When Should You Use Unshielded Cables?
Homes, small offices, and retail spaces are examples of environments in which unshielded cabling tends to be used. UTP cables are generally cheaper to buy and install than shielded alternatives. They’re also lighter, more flexible, and simpler to terminate than shielded cables, which makes them ideal for straightforward cable runs.
Unshielded cables are, though, relatively susceptible to interference, with performance issues potentially arising in the event of them being installed near power cables, heavy machinery, or lift motors. Their reliability can also sometimes be weaker than that of shielded cables in electrically noisy locations.
All in all, you may decide in favour of unshielded cables when:
- The environment is a low-interference one; typical homes and offices, for instance, rarely generate sufficient EMI to justify shielding
- Cable runs are short, as shorter runs are generally less susceptible to attenuation and external interference
- Your budget is relatively tight, as UTP cabling is more cost-effective for large installations with straightforward requirements
- Simplicity is important, as unshielded cables are easier to work with when it comes to DIY installations or quick deployments.
When Should You Use Shielded Cables?
Commonly used across such settings as factories, warehouses, hospitals, and data centres, shielded cables offer better protection against EMI than their unshielded equivalents. They’re also characterised by improved signal integrity and better performance in demanding environments.
But on the other hand, shielded cables do tend to be more expensive than unshielded ones, in addition to being less flexible and more complex to install.
On balance, then, a shielded cable might be the better option of the two when:
- The cables need to run near power infrastructure, as shielding helps maintain signal quality
- The environment contains heavy electrical equipment, which can often create substantial EMI
- High-speed data reliability is needed; 10Gb Ethernet and other high-bandwidth systems may benefit from shielding in environments with significant EMI and cable density
- Regulatory or industry standards necessitate the use of shielded cabling.
It is important to note that shielded cabling must be properly grounded throughout the installation if it is to provide effective protection against interference.
Conclusion: Which Cable Type Should You Opt For?
In summary, as far as most homes, small offices, and other low-interference environments are concerned, unshielded cabling will typically do the job fine. But if the system or project you’re working on presents a risk of interference, high speeds, or industrial conditions adversely impacting on reliability, you might be much likelier to place your trust in shielded cables instead.
The best choice on unshielded versus shielded cables will ultimately come down to the specific environment, performance requirements, budget, and installation quality.
