When installing an HVLS (High-Volume, Low-Speed) fan, safety is a top priority—especially in a country like New Zealand, where seismic activity is a reality. While large ceiling fans significantly improve airflow and comfort in warehouses, gyms, and commercial spaces, securing them properly is just as important as their performance.
Fortunately, Big Ass Fans (such as the Powerfoil X3 HVLS fan) are designed with multiple redundant safety features, including dual mounting systems, aerospace-grade hub retainers, and robust structural integrity, making them the preferred choice for safety-conscious buyers. However, proper seismic restraints are still essential in earthquake-prone regions to ensure additional stability.
One common misconception is that chains and turnbuckles provide sufficient seismic restraint due to their high load-bearing capacity. However, strength alone doesn’t make them suitable for seismic events. Let’s dive into why engineered seismic restraint systems like our preferred suppliers Gripple or V-Lock are the smarter, safer choice.
What Happens to HVLS Fans in an Earthquake?
During an earthquake, everything in a building - including the structure itself - moves unpredictably. This sudden movement can cause an unrestrained HVLS fan to swing excessively, putting stress on its mounting points, nearby structures, and even electrical wiring. Without proper restraints, the worst-case scenario is the fan detaching completely - creating a major safety hazard for people and equipment below.
That’s where seismic restraints come in. They’re designed to keep the fan in place while absorbing kinetic forces, preventing excessive swaying, detachment, or secondary damage to ceilings, trusses, or sprinkler systems.
Why Are Chains & Turnbuckles Not a Suitable Seismic Solution?
At first glance, chains and turnbuckles might seem like a solid option. After all, they’re strong and widely used in overhead rigging. However, they have critical limitations when it comes to seismic performance:
1. No Kinetic Energy Absorption = Increased Risk of Failure
Chains and turnbuckles are rigid and do not absorb seismic shock well. In an earthquake, they can allow the fan to swing like a pendulum, transferring uncontrolled force to the mounting system. Seismic-rated restraints, on the other hand, are designed to absorb and distribute energy safely, preventing sudden stress spikes that could lead to failure.
2. Excessive Movement & Swinging
Because chains are flexible, they allow excessive side-to-side movement. This can cause the fan to collide with:
- Ceilings
- Ducting and ventilation systems
- Sprinklers and fire suppression equipment
- Electrical conduits
- Trusses or beams
Seismic-rated restraint systems limit movement to a controlled range, reducing the risk of secondary damage.
3. Risk of Loosening Over Time
Turnbuckles are prone to loosening due to fan vibrations and environmental factors. Even if initially secure, seismic shaking can cause them to slip or unscrew, leaving the fan vulnerable. Seismic-rated restraints, like Gripple and VLock, feature tension-controlled mechanisms that remain locked in place even under extreme conditions.
4. Chains Create Shock Loads on Anchor Points
If chains have any slack (which is common due to natural settling and vibration over time), they will suddenly snap tight when an earthquake hits. This creates a shock load on the anchor points, which can:
- Exceed the rated capacity of the structure
- Lead to bracket or bolt failure
- Damage the ceiling or mounting system
Engineered seismic restraints are pre-tensioned, meaning they are always engaged and do not experience sudden force spikes.
5. Compliance with NZ Building Codes
New Zealand has strict seismic regulations, and restraints must meet NZS 4219:2009 (Seismic Performance of Engineering Systems in Buildings). Chains and turnbuckles are not rated for seismic use and may fail compliance checks.
If an improperly restrained fan causes damage or injury, it could lead to insurance issues, liability concerns, and costly repairs.
The Smart Choice: Gripple & VLock Seismic Systems
Seismic-rated systems like Gripple and VLock are designed specifically for earthquake-prone regions like New Zealand. Here’s what makes them superior:
✅ Energy absorption – Prevents excessive forces from transferring to mounting points.
✅ Controlled movement – Limits swaying and prevents secondary damage.
✅ Pre-tensioned & locked – No risk of loosening like turnbuckles or chains.
✅ Code-compliant – Meets NZ seismic safety standards.
✅ Lower maintenance – No need for constant re-tightening or checks.
While chains may seem like a quick fix, seismic-rated restraints provide peace of mind, compliance, and most importantly, safety.
Final Thoughts
If you’re installing an HVLS fan in an earthquake-prone region, it’s crucial to think beyond just holding it up—you need to ensure it stays secure when the ground shakes. Chains and turnbuckles might be strong, but they lack the energy absorption, controlled movement, and long-term security of engineered seismic restraint systems.
Investing in Gripple or VLock seismic restraints isn’t just about following the rules—it’s about protecting your people, equipment, and business from unnecessary risk. When safety is non-negotiable, choosing the right seismic restraint system is a must.
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