RectorSeal Corp., Houston, TX, a leading manufacturer and U.S. distributor of quality HVACR products, introduces the SlimDuct RD-Series and the PD-Series, the world's only commercial rooftop ducting and support systems that are designed exclusively for multiple linesets as used with variable refrigerant flow (VRF) multi-split systems or any other conventional air-conditioning and refrigeration systems.

RectorSeal officials say the RD-Series and PD-Series are the most practical, economical, durable and professional solutions for protecting the multiple linesets commonly used on rooftop VRF systems, a mature industry in Asia which is quickly emerging in North America. Both series save more than 75% in labor time when compared to the alternative of custom-fabricated galvanized sheet metal lineset ducting or other labor-intensive fabrications.

The RD-Series comprises 20-gauge, roll-formed rectangular sheet metal lineset duct and fittings. It features a proprietary, anti-corrosive, scratch-resistant hot-dipped and chromium-free ZAM coating (Zinc, Aluminum and Magnesium) that provides a superior, more durable and lighter weight alternative to galvanized steel. Widths for the RD-300, RD-450, RD-600 and RD-900 are 12-, 18-, 24- and 36-in. respectively and all are 5-1/8-in. high. Based on a 3/8 x 3/4-in. lineset with 1/2-in. insulation on both lines, the RD-Series can accommodate the following number of linesets: RD-300 (8), RD-450 (12), RD-600 (19) and RD 900 (25).  

This Series for Smaller Installations
The PD-Series is designed for smaller installations which do not warrant the larger metal lineset duct. It also serves as a transition to protect the lineset from where it exits the VRF condenser until it enters the RD-Duct. The PD-Series  differs from the RD-Series in that it consists of UV, fire and weather-resistant  ivory-colored extruded PVC round duct in 2 sizes only, PD-90 (3.5-in. diameter), & PD-120 (4.7-in. diameter), and is available in 39-in. & 60-in. lengths.

Because of its sleek profile, smooth surface and neutral color, the PD series is perfectly suitable for use indoors to conceal and protect unsightly exposed linesets, drain lines and cables.

Similar to the RD-Series, each size comes with a selection of fittings, 90 &  45 degree ells, couplers, tees, wall flanges, end caps and mounting brackets which can be customized to suit any lineset configuration.

Other features of the RD-Series and PD-Series include:

  • According to third-party tests performed by the Building Center of Japan and Japan's Civil Engineering Research Center, the RD-Series is certified more corrosion-resistant than galvanized steel.
  • Both series carry a two-year warranty, and can be used vertically or horizontally to protect linesets associated with any air conditioning, refrigeration or industrial cooling process equipment.
  • RectorSeal offers free design services through their Japanese trained technical support personnel.
  • On rooftop systems when the top of the RD-Series duct (Type RWK) has to be used as walkways, a reinforced heavier gauge cover plate with a non-skid surface is available as a special order option.
  • RectorSeal stocks the full range of PD-Series as well as the RD-300, RD-450, & RD-600 sizes. The RD-900 size is available only on special order.

The RD-Series is available only through RectorSeal’s network of accredited bid/spec representatives. The PD-Series is also available through these bid/spec reps, however it is also freely available through most wholesale HVACR distributors.