Insulated door engineered for sub-zero and deep-freeze rooms, with a heated track and frame to defeat ice build-up.
At −25 °C and below, an ordinary cold room door freezes shut: ice jams the track, stiffens the gasket and locks the leaf in place. This door fights back with a heated track, heated frame and heated bottom edge that keep the running gear and seals ice-free — so it opens on demand, every time, in the coldest rooms.
One idea: below about −18 °C, moisture in the air freezes onto the coldest surfaces first — and the door frame and track are exactly those surfaces. Without heat, ice builds up until the door jams and the seal fails.
Each time a deep-freeze door opens, warm humid air enters and deposits frost on the frame, track and gasket. Cycle after cycle, that frost turns to ice: the leaf sticks to its gasket, rollers jam in the track, and operators force the door — damaging seals and hardware. In the worst case a door freezes shut and staff cannot get in or out safely.
RAX solves this with a low-wattage heating element running through the track, frame and bottom edge, held just above freezing so ice cannot form while the door stays cold on the room side. Combined with a thick 150 or 200 mm PU panel and a continuous silicone gasket, the door keeps its seal and its movement in continuous deep-freeze service. Heating layout, panel thickness and the final thermal figure are confirmed on your specification, and every unit is made to order from a single door, in any size and any RAL colour.
Temperature bands and panel-thickness guidance are industry-typical ranges for deep-freeze construction; RAX confirms the exact rating for your room per project. The U-value is stated as a “down to” marketing reference for the insulated panel, not a tested door-set figure. RAX products are validated from −30 °C cold storage to +50 °C desert conditions.
Every door is engineered to your opening and your room temperature. The values below are the validated baseline; final figures are confirmed on your specification. Each row states whether the value is RAX-measured, industry-typical or set per project.
| Parameter | Specification | Basis |
|---|---|---|
| Door Type | Insulated deep-freeze door (sliding or hinged) with integrated anti-freeze heating. | Product definition |
| Anti-Freeze Heating | Heated track, frame and bottom edge; low-wattage element held just above freezing on the warm side. | RAX build |
| Insulation Core | High-density PU foam panel, 150 / 200 mm for deep-freeze temperature holding. | Per project |
| Temperature Band | Frozen −18 to −25 °C and deeper sub-zero / blast duty on request. | Industry-typical |
| Thermal Performance | U-value down to 0.33 W/m²K for the insulated panel construction (marketing reference, not a door-set test). | Marketing value |
| Cycle Life | 100,000 cycles validated in the RAX 100,000-cycle fatigue test lab. | RAX-measured |
| Sealing | Continuous silicone rubber perimeter and bottom gasket, formulated to stay flexible at sub-zero temperature. | RAX build |
| Panel Skins | Galvanized steel sheet (0.4–1.5 mm); stainless steel 304/316 available for hygienic rooms. | RAX build |
| Frame | Aluminum alloy profile 6063-T5; thermal-break detail to limit cold bridging around the heated zone. | RAX build |
| Heater Supply | 220V / 380V, 50/60Hz; wiring diagrams supplied; thermostatic control to limit energy use. | Per project |
| Safety | Internal safety release, anti-pinch edge; vision window (clear PVC / polycarbonate) optional. | RAX build |
| Operating Range | Validated from −30 °C cold storage to +50 °C desert conditions. | RAX-tested |
| Fire Rating | EI60 / EI120 available — engineered and tested per project. | Per project |
| Max Opening | Custom to your opening — confirm on technical layout. | Per project |
Need a U-value, air-permeability or fire figure certified for tender? We arrange third-party test data against the matching standard per project — see Compliance below.
Validated substrates, processed in-house on an auto PU foam panel line and CNC punching/bending centre. The heating element is integrated into the frame and track as one engineered assembly.
The coldest rooms where a standard cold room door would freeze shut.
Your installers get the full document set before the door ships — including the heater wiring your electrician needs.
Certificates we hold today, and the project-specific test data we arrange against the matching standard. We state held vs. per-project so you can tender honestly.
Rigorous 100,000-cycle fatigue testing, validated galvanized steel and aluminum alloy materials, and precision manufacturing — performed in-house, not outsourced.
Large industrial doors from prototype to container-load delivery. Start with an OEM sample and scale to container-load branded production.
Every deep-freeze door is built to your opening and your room. Send the clear opening size, the lowest room temperature, sliding or hinged preference and the available heater supply voltage (or site photos) and our engineers return a proposal, technical confirmation and lead time.
From custom engineering to container-load delivery — the document set your local installers need.
Warranty: door body 2 years · operator/motor 3 years · servo motor 5 years. Free spare parts within warranty (DHL/FedEx 5–7 days). Lead time: sample 7–15 days · standard container 12–20 days · custom first order 20–35 days.
Below about −18 °C, moisture that enters with each opening freezes onto the coldest surfaces — the frame, track and gasket. Over time that frost turns to ice, jamming rollers and sticking the leaf to its seal until the door will not open. A heated track, frame and bottom edge are held just above freezing so ice cannot form, keeping the door moving and the seal intact in continuous sub-zero service.
No. The heater is a low-wattage element controlled by a thermostat, so it only maintains the frame and track just above freezing rather than heating continuously at full power. The thick 150 or 200 mm PU panel and the thermal-break frame keep the heat on the warm side, so the running cost stays small relative to the refrigeration load it protects.
For frozen rooms at −18 to −25 °C we typically specify 150 mm, and for deeper deep-freeze or blast rooms 200 mm, to hold temperature and prevent condensation on the warm face. These are industry-typical guidelines; RAX confirms the right thickness and the resulting thermal performance for your specific room on the technical layout.
The heating element runs on 220V or 380V at 50/60Hz, matched to your site supply, and we provide the heater wiring diagrams with every order so your electrician can connect it correctly. Tell us your available supply at quotation and we size the heater circuit accordingly.
RAX holds ISO 9001:2015, CE marking against EN 13241 (industrial door product standard) and EN 12453 (operator safety), plus SGS material reports and Product Liability Insurance. Fire rating (EI60/EI120) and AS/NZS 4505 / UL counterpart test data are arranged per project, not held as standing certificates.
Yes. Every door is engineered to your clear opening, sliding or hinged, fully custom-engineered to your opening in any RAL colour. Full OEM/ODM is supported — private label, packaging printing and manual translation (EN/ES/FR/AR/RU) — under strict NDA.
Sample orders run 7–15 days, a standard container 12–20 days, and a custom first order 20–35 days (repeat custom orders 15–20 days). FOB ports are Tianjin and Qingdao; FCL and LCL are both supported. The door body is warranted for 2 years and the operator/motor for 3 years (servo motor 5 years), with free spare parts shipped by DHL/FedEx within warranty.
Every order includes installation guides and heater wiring diagrams, an English installation manual, FAI first-article confirmation and pre-assembly photos, a factory inspection report (insulation resistance, noise, visual and function tests), the 100,000-cycle fatigue test video/report, and the CE Declaration of Conformity with the EN 13241 test report.
Send your opening size (W × H), lowest room temperature and heater supply voltage. Our engineers reply with a proposal and lead time — no obligation.
