An EPP plenum box moulded from expanded polypropylene. EPP is exceptionally light while still being rigid and impact-resistant, and it also has useful thermal and acoustic properties, so the box contributes to both condensation control and noise reduction without any additional lining. Manifold configurations are available from five to seven ways.
In ceiling voids, plant rooms and riser cupboards, distribution boxes is rarely the whole system — it is one link in a chain. Getting it wrong shows up later as unbalanced branch flows, pressure drop at junctions and space constraints. The selection criteria that actually drive performance are branch count, port configuration and pressure loss, and those are the three things a buyer should confirm before placing an order.
A radial system runs an individual duct from the distribution box to each terminal, which means every branch can be sized precisely for its own flow and adjusted without affecting the others. A trunk-and-branch system shares a common run and branches off it, which uses less material but makes balancing considerably harder. For residential MVHR the radial approach has become the default because the additional duct cost is small, the pressure loss is lower, and commissioning is dramatically simpler. The distribution box is the component that makes this possible.
The number and arrangement of ports on a distribution box should follow the building layout, not the other way round. A box with eight ports arranged evenly around its circumference suits a central plant position with branches radiating outwards. A box with ports grouped on two faces suits a unit mounted against a wall. Getting this wrong means that half the branches have to double back on themselves, which adds length, pressure loss and cost. Port configuration is the specification decision that most affects the total length of duct in the system.
Every EPP Air Distribution Box | Fresh Air Manifold Plenum Box we ship is produced on our own production line in Dezhou, Shandong, China. Because we control the tooling and the forming equipment directly, we can guarantee that the product you receive in container three is dimensionally identical to the sample you approved in the first order. That consistency is difficult to achieve when production is outsourced, and it is the single most common complaint we hear from buyers who have tried sourcing this category through intermediaries.
Our mould shop supports custom development for EPP Air Distribution Box | Fresh Air Manifold Plenum Box. If your project needs a non-standard size, a specific wall thickness, a particular colour or a branded face plate, we can build the tooling and run a trial batch for approval before committing to a full production run. Typical custom development takes two to four weeks from drawing approval to first article, depending on the complexity of the part.
Confirm the exact size or model you need against the specification table below. Where a project mixes sizes on one run, check that every transition is made with a matching reducer rather than by forcing parts together — the latter is the single most common cause of leakage and pressure loss on site.
The material and layer build-up determine how the product behaves over a 15–25 year service life. Read the construction column carefully: two products that look identical on a photograph can differ entirely in wall thickness, insulation layer and fire performance.
| Item | Specification |
|---|---|
| Available Sizes / Models | 75/110 |
| Description | 5ways / 6 ways / 7 ways |
| Material / Construction | EPP |
Pairs with HDPE corrugated pipe, pre-insulated radial ducting, straight couplings and ceiling diffusers. For the ABS equivalent see our ABS air distribution box.
GUANDE manufactures EPP Air Distribution Box | Fresh Air Manifold Plenum Box 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. Because we manufacture this product in our own plant, we control the tooling, wall thickness, material grade and quality inspection at every stage — not just the final packing. That means we can produce non-standard sizes, custom colours and private-label versions against your drawings, and we can adjust a production run when a project specification changes. Tell us your target market and we will confirm packaging, labelling and documentation to suit it.
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 EPP different from ABS for this application?
A: EPP is lighter and brings some thermal and acoustic benefit; ABS is denser and offers a harder, glossier surface.
Q: Which manifold sizes are available?
A: Five, six and seven-way versions are listed in the specification table below.
Q: Can outlet ports be customised?
A: Yes, custom port arrangements can be quoted for project orders.
The southeast corner of the private entrepreneurship park in Huadian Town, Qihui County, Dezhou City, Shandong Province