This page sets out the technical specification of Adjustable Round Jet Air Diffuser Fresh Air Ceiling Air Vent as supplied by GUANDE, together with the selection rules that determine which variant suits a given project. It is written for specifiers, estimators and contractors who need to confirm a size, a material build-up and a connection method without waiting on a quotation.
| Item | Specification |
|---|---|
| Available Sizes / Models | Ø75mm, Ø100mm, Ø150mm, Ø200mm, Ø250mm |
| Description | Rotatable adjustable circular jet air outlet, multi-ring air guide structure, stepless air volume control, spring buckle embedded ceiling installation, suitable for fresh air supply and ventilation systems. |
| Material / Construction | High-quality ABS Plastic |
An adjustable circular jet diffuser with a multi-ring air-guide core. Rotating the inner rings changes both the air pattern and the throw distance, so a single diffuser can serve a long room or a high ceiling without being swapped. Air volume is controlled steplessly. It snaps into a plasterboard ceiling with the spring-buckle ring, exactly like a fixed grille.
Terminals are frequently the loudest component in a ventilation system, and the reason is usually self-inflicted. Air forced through an undersized opening generates velocity noise that no amount of upstream attenuation will remove. The practical rule is that terminal velocity should be kept low enough that the terminal itself makes no contribution to the room noise level, and that the duct feeding it should be one nominal size larger than the terminal if the run is short. Designers who chase small face dimensions for aesthetic reasons usually pay for it in noise.
Where a supply terminal is placed matters as much as how it performs. A supply diffuser mounted directly above an extract grille short-circuits the air straight back out of the room without ever conditioning the occupied zone. A terminal placed in a corner will produce a completely different air pattern from the same unit placed centrally. Good practice is to position supply terminals to wash the occupied zone and to keep extract points on the opposite side of the room, ideally above humidity or odour sources.
Terminals are the visible face of the ventilation system, and they are judged on appearance as much as on performance. ABS and similar engineering polymers are the default choice because they hold their shape, resist discolouration and can be finished in a wide range of colours to match ceilings. Powder-coated steel is used where mechanical protection matters. For projects with specific interior requirements, colour matching and OEM branding are routinely available subject to minimum order quantities.
Quality inspection at GUANDE is not a final gate — it runs through the whole process. Incoming raw material is checked against specification before it enters production. In-process checks monitor dimensions and surface finish at defined intervals during the run. Finished Adjustable Round Jet Air Diffuser Fresh Air Ceiling Air Vent are inspected against the approved sample, and a batch record is kept against every shipment so that any issue can be traced back to its production parameters.
Our plant runs scheduled production for Adjustable Round Jet Air Diffuser Fresh Air Ceiling Air Vent with typical lead times of 15 to 25 days for standard items and 25 to 40 days for custom tooling projects. We load mixed containers directly at the factory, which lets us combine several product lines from your ventilation schedule into one shipment and reduce freight cost per unit. Confirmed lead times are stated on the order acknowledgement, not estimated at enquiry.
Use the following rules when converting a project drawing into an order. They reflect how the product performs in living rooms, bedrooms, kitchens, bathrooms and corridors, where the practical limits are usually set by effective open area, throw pattern and noise level rather than by the headline dimension.
Size the run from the design air flow and the acceptable pressure drop, not from the fan spigot. Undersizing a air terminals run is the most common specification error and it cannot be corrected later without re-opening the ceiling.
Where the run passes through an unconditioned space, condensation risk — not mechanical strength — normally decides the specification. In those locations the insulated variant is the correct default and a bare equivalent is a false economy.
Keep one connector family for the whole run. Every change of system introduces an adapter, and every adapter is an additional leak path and pressure loss point.
Connects to HDPE corrugated pipe and flexible aluminium duct. Combine with our manual air volume dampers for branch-level regulation.
GUANDE manufactures Adjustable Round Jet Air Diffuser Fresh Air Ceiling Air Vent at our factory in Dezhou, Shandong, China, and ships direct to HVAC contractors, distributors and project specifiers worldwide. Wholesale, OEM and ODM programmes are welcome. Items are supplied in export cartons with the size and quantity marked on the outer label. For OEM programmes we can apply your own artwork and labelling subject to a minimum order quantity.
The products below are routinely specified alongside the item discussed in this guide. GUANDE manufactures the full range in our own plant for consolidated shipping:
Q: How is the throw distance adjusted?
A: By rotating the inner jet rings. The multi-ring structure changes the discharge pattern, which in turn changes throw and induction.
Q: Does it need a separate volume damper?
A: No. Air volume can be trimmed steplessly at the diffuser itself.
Q: Which diameters are stocked?
A: See the specification table below; other diameters can be quoted on request.
The southeast corner of the private entrepreneurship park in Huadian Town, Qihui County, Dezhou City, Shandong Province