Estimated Delivery: 2–5 Working Days
Enter postcode in checkout for delivery cost
View transport policyThe Swirl Diffuser Plenum Box 400 is a high-performance air distribution unit designed to provide efficient and uniform airflow in HVAC systems. It combines a plenum box with a swirl diffuser to deliver 360° air distribution, minimizing drafts and maintaining optimal comfort levels in commercial, industrial, and residential spaces. The 400 mm size makes it suitable for medium-duty duct systems, ensuring precise and quiet air delivery.
Material:
Plenum box: Galvanised steel or powder-coated sheet metal for durability
Diffuser: Aluminium or steel with precision-engineered swirl blades
Corrosion-resistant finish for long-term reliability
Specifications:
Size: 400 mm (square or circular dimension based on model)
Provides 360° swirl airflow distribution
Compatible with standard ductwork connections
Reduces drafts and noise in conditioned spaces
Easy installation with standard mounting hardware
Suitable for ceiling, wall, or floor-mounted HVAC applications
Durable and corrosion-resistant construction
At Direct Duct Supplies, we are committed to delivering your orders quickly, safely, and efficiently. Below you will find our shipping procedures and policies. If you have any specific delivery deadlines or special requirements, please contact our team and we will do our best to assist.
We work hard to get our customers what they need when they need it. Below you will find information on our delivery service. If you have a particular need or deadline, please contact us and we’ll do our best to accommodate you.
Delivery Charges
Delivery charges vary depending on the size, weight, and value of your order. Shipping costs are calculated at checkout and clearly displayed on the My Basket page before you complete your purchase.
We offer a range of delivery options, including free delivery on selected orders, with standard delivery charges typically ranging between £20 and £40 depending on the service selected.
Delivery Time (UK)
We offer fast and reliable UK delivery, with most orders arriving within 2–5 working days from the date of purchase.
Smaller items typically arrive within 2–4 working days, while larger or heavier items may take 3–5 working days. Delivery times may vary slightly during busy periods or holidays.
Easy & Convenient Delivery
We use a combination of in-house logistics and trusted UK courier partners including Royal Mail, DPD and DX. This allows us to provide reliable delivery coverage across the UK. Once your order has been dispatched, you will receive an email confirmation with tracking details. You can also track your delivery via the My Account section.
Next Day Delivery
We offer next working day delivery on selected items and order types. Availability and pricing depend on the size, weight, and order value. Please contact us prior to ordering to confirm eligibility and we will do our best to arrange this.
International, Scottish Highlands, Islands & Northern Ireland
We are able to ship orders internationally, as well as to the Scottish Highlands and offshore locations. Please contact us for a delivery quote before placing your order.
Please note that some items may not be eligible for international shipping due to size or weight restrictions.
