Ulti DuoTherm Blast Explained: Engineered for Performance in Extreme Cold

Blast freezer environments push equipment to the edge – demanding unmatched durability, insulation, and safety. Whether you’re working in cold storage logistics, food processing, or temperature-sensitive distribution, maintaining operational efficiency in these high-pressure settings is critical.

The Ulti DuoTherm Blast is Ulti Group’s specialist solution for exactly this environment. Purpose-built in New Zealand, this double-insulated rapid door combines thermal performance with safety-first engineering to deliver a market-leading blast door that stands up to extreme cold and pressure – while helping facilities save energy, lower operating costs, and increase productivity.

 

Key Features of the Ulti DuoTherm Blast

The Ulti DuoTherm Blast isn’t just an upgraded door – it’s a re-engineered access solution designed specifically for high-performance freezer environments. Its standout features include:

• Double-insulated reinforced PVC curtains with a treated air gap for thermal separation and ice resistance
• Thermal transmittance (U-value of 1.5 W/m²K for superior insulation and energy savings
• Pressure differential tolerance up to 60 Pa, enabling high-performance sealing during blast cycles
• Opening speed up to 1 m/s and closing speed up to 0.8 m/s, supporting faster operations
• Compact design with no overhead panel, ideal for tight installations with minimal clearance
• Enhanced safety systems including infrared safety beams, soft PVC bottom edge, and manual egress crank
• NZ-designed and built, ensuring local support and service availability

 

How the DuoTherm System Works

At the core of the Ulti DuoTherm Blast is its innovative dual curtain system. This design features two independently insulated PVC curtains with a controlled air gap between them. When the door is closed during blast freezing, the air gap acts as an insulating buffer, maintaining internal freezer temperatures while resisting ice build-up on the curtain surface.

The curtain itself is guided in self-lubricating polyethylene tracks with injection-moulded teeth – and approach borrowed from Ulti Group’s proven rapid door technology. This reduces wear, eliminates the need for metal parts in the curtain, and minimises the risk of operational damage from impacts or collisions.

Together, these design elements enable the door to form a tight, pressure-resistant seal that holds against the high-speed airflow and pressure changes of blast-freezing cycles – while maintaining consistent insulation and reducing downtime.

 

Benefits of the Ulti DuoTherm Blast

1. Energy Efficiency That Delivers Savings

The advanced thermal performance of the Ulti DuoTherm Blast directly translates into lower energy consumption. The double-insulated design significantly reduces cold air loss, meaning blast freezers don’t need to work as hard to maintain target temperatures. The result? Less load on refrigeration systems and lower energy bills over time.

2. Improved Productivity

Fast opening and closing speeds – up to 1 metre per second – enable rapid access while minimising thermal leakage. This allows quicker transitions between freeze cycles, improves workflow, and limits ice formation at the opening, which reduces defrosting time and associated maintenance costs.

3. Superior Safety

The DuoTherm Blast prioritises safety by eliminating overhead panels, a known hazard in traditional sectional doors. Its side-mounted structure removes the risk of falling components and ensures a clean overhead area. Integrated features like infrared safety beams, LED countdown timers, soft bottom edges, and a manual crank provide multiple layers of protection for operators and equipment.

4. Lower Lifetime Costs

Built for longevity, the curtain design eliminates metal within the curtain assembly and relies on robust, low-maintenance tracks. This reduces mechanical wear and impact-related damage – resulting in fewer service calls and a longer life cycle. With fewer moving parts and less required maintenance, the door offers a clear cost advantage over time.

5. Flexible Fit and Minimal Footprint

With minimal space requirements – only 1000mm of headroom and 500mm of sideroom – the Ulti DuoTherm Blast is ideal for installation in areas with tight clearances, narrow access points, or closely spaced freezer rows. It can be adapted to new builds or retrofitted into existing facilities, making it highly versatile.

6. Built for Extreme Environments

Operating effectively in temperatures from -30°C to +15°C, the door is engineered to handle the extreme conditions of blast freezers. It also includes heated frame elements, a thermal isolation mounting system, and optional upgrades such as humidity control and wind retention kits for further environmental protection.

7. Customisable and Compliant

The door complies with standard wind and water permeability ratings and offers a range of optional features, including:

• IP65-rated motor for corrosive environments
• Virtual vision and extended LED alerts
• Custom control box and motor placement
• Multiple colour options for frame and curtain

This flexibility allows customers to tailor their doors to suit their unique site needs and regulatory requirements.

 

Cold storage operations demand doors that can handle extremes – and the Ulti DuoTherm Blast is built to meet that demand. Its cutting-edge design ensures your facility gains in energy efficiency, safety, and productivity – without compromising on durability or ease of use.

Whether you’re building a new blast freezer or upgrading an outdated sectional door, the Ulti DuoTherm Blast is a future-ready solution that’s been proven in high-pressure environments across New Zealand and Australia.

 

Looking to optimise your blast freezer performance?

Get in touch with Ulti Group to discuss how the DuoTherm Blast can help you conserve energy, reduce costs, and keep your people safe – no matter how cold it gets.