Runtal VLX Series Wall Panel Radiators

Runtal VLX Series wall panel radiators are made-to-order hydronic heating panels manufactured in the USA from cold rolled low carbon steel, available in six tube-count configurations ranging from 5 tubes (14.4 inches tall) to 10 tubes (29 inches tall), with lengths spanning 20 inches to 29-1/2 feet in 2-inch increments. All Runtal VLX Series wall panel radiators include integral fins, which increase output over the fin-free VX counterparts, with the finned VLX35/35 delivering 1,240 BTUH per foot and the VLX70/56 reaching 2,020 BTUH per foot at 180°F AWT. Wall panel radiators in the VLX Series mount flush against the wall at just 2 inches of depth, freeing floor space and allowing curtains to hang naturally to the floor when installed under windows. For any hydronic system where radiant and convective output need to coexist in a slim, wall-hugging profile, Runtal VLX Series wall panel radiators are a proven fit.

KEY SUBCATEGORIES / PRODUCT TYPES

VLX Series wall panel radiators with fins, versus the fin-free VX Series, are the first configuration decision to make. Both series share the same outer dimensions and wall appearance, but adding fins meaningfully increases output per foot. The VLX35/35 (5 tubes, 14.4 inches tall) produces 1,240 BTUH per foot with fins versus 700 BTUH per foot without. The VLX56/56 (8 tubes, 23.1 inches tall) delivers 1,810 BTUH per foot with fins versus 1,130 BTUH per foot without. When the room's heat loss calculation calls for more output from a given linear run of wall, the finned VLX configuration closes the gap without adding wall projection or height.

Low-height VLX configurations, specifically the VLX7/7 (2.8 inches tall) through VLX21/21 (8.6 inches tall), are sized for situations where the window sill is low or a continuous run along a knee wall is the only available surface. The VLX14/14 produces 600 BTUH per foot at 180°F AWT and works in both high and low temperature closed-loop systems. Contractors replacing fin-tube or cast iron baseboard often find the VLX14/14 and VLX21/21 direct drop-in fits dimensionally and output-wise, using existing piping and simply ordering the appropriate length.

Mid-height VLX configurations, the VLX28/28 (11.5 inches tall, 930 BTUH per foot) and VLX35/35 (14.4 inches tall, 1,240 BTUH per foot), cover the majority of residential and light commercial room heat loads. The VLX35/35 is well suited for under-window placement in standard-height residential construction where sill heights allow, providing enough output to counter cold-glass downdraft while keeping the profile low enough for drapes to clear the top of the panel.

High-output VLX configurations, the VLX42/42 (17.3 inches, 1,430 BTUH per foot) through VLX70/56 (29 inches, 2,020 BTUH per foot), handle larger glazing areas, entryways, and rooms with high heat loss. The VLX56/56 at 1,810 BTUH per foot and the VLX63/56 at 1,890 BTUH per foot suit large window-wall applications where a shorter run of radiator needs to carry a heavy load. Runtal rates all VLX output figures at 180°F AWT; for mod-con boiler systems running lower supply temperatures, the published correction factor tables should be used to size accordingly.

Piping connection configuration is made-to-order at time of purchase and cannot be changed after manufacturing. Each Runtal VLX Series wall panel radiator may be piped eight different ways, covering left-hand supply, right-hand supply, bottom, and opposite-end series arrangements. Specifying the connection type upfront, and cross-checking it against the trim cover layout planned for the installation, prevents the most common callbacks on VLX jobs.

BUYING GUIDE / HOW TO CHOOSE

Sizing Runtal VLX Series wall panel radiators correctly starts with a room-by-room heat loss calculation, not a rule-of-thumb estimate. Wall panel radiators are specified by BTUH per foot at a given average water temperature (AWT), so the design AWT needs to be locked in before any model selection. All published Runtal VLX output figures are at 180°F AWT. Running a condensing boiler at lower supply temperatures, say 140°F AWT, changes the math considerably. At 140°F, the VLX35/35 drops from 1,240 BTUH per foot to roughly 712 BTUH per foot based on Runtal's published correction factors, which means a longer run or a taller tube count will be needed to hit the same load. Plug the design AWT into the correction factor table before finalizing any length or height selection.

Height selection in Runtal VLX Series wall panel radiators is driven by available wall space, not personal preference. A lower sill height limits the panel height; a room with modest heat loss may not need the tallest option available. When two height options could work, the shorter VLX configuration at greater length often provides better heat distribution than a taller panel in a shorter run. Wide, low panels spread heat more evenly across the perimeter of a room than a tall, short segment.

Piping configuration and connection type must match the roughed-in piping and the trim cover plan. Runtal offers eight piping arrangements per radiator. In series installation, an individual loop should not exceed 30,000 BTUH or 7 radiators per Runtal's documentation. Same-end series piping is limited to no more than 3 radiators per loop. Opposite-end series connections allow up to 7 radiators and carry lower pressure drop. Testing the system with air at a maximum of 50 PSI before wet testing, and venting each panel with the system pressurized and pumps off, are the two installation steps most often skipped on first installs and most often causing callbacks.

Color selection is practical, not just aesthetic. Ten standard colors ship fastest; designer and custom colors require additional lead time. If a tight schedule is a factor, confirm color availability before committing to the specification.

FAQs

What are the BTUH per foot ratings for Runtal VLX Series wall panel radiators?

The BTUH per foot output of Runtal VLX Series wall panel radiators varies by tube count and is rated at 180°F AWT. The VLX35/35 (5 tubes, 14.4 inches tall) produces 1,240 BTUH per foot, the VLX56/56 (8 tubes, 23.1 inches tall) produces 1,810 BTUH per foot, and the VLX70/56 (10 tubes, 29 inches tall) reaches 2,020 BTUH per foot. All figures apply to the finned VLX configurations; the fin-free VX counterparts produce lower outputs from the same panel dimensions.

How do Runtal VLX Series finned panels compare to VX Series panels without fins?

The difference between Runtal VLX Series (with fins) and Runtal VX Series (without fins) is output per foot, with panel dimensions and appearance being identical when installed. The VLX35/35 finned panel delivers 1,240 BTUH per foot versus 700 BTUH per foot for the VX35 fin-free version, a difference of 540 BTUH per foot from the same 14.4-inch-tall, 2-inch-deep panel. Fin selection is determined by the room's heat load and the length of wall available to run the radiator.

What lengths are Runtal VLX Series wall panel radiators available in?

Runtal VLX Series wall panel radiators are available from 20 inches to 29-1/2 feet in length, manufactured in 2-inch increments. The made-to-order nature of the VLX Series means length is specified at time of order and fabricated to match the design requirement, rather than selected from a set of fixed stock lengths.

Can Runtal VLX Series wall panel radiators be used with a condensing boiler running lower water temperatures?

Runtal VLX Series wall panel radiators can be used with lower supply temperature systems, including condensing boilers, but output per foot decreases as AWT drops below the 180°F rated condition. Runtal publishes correction factor tables that allow the designer to calculate actual BTUH per foot at any AWT, which is required to size the radiator correctly for low-temperature operation. Consulting Runtal's engineering documentation rather than relying on the 180°F rated output is the right approach when designing for condensing boiler supply temperatures.

What piping connection options are available for Runtal VLX Series wall panel radiators, and when does the choice need to be made?

Runtal VLX Series wall panel radiators may be piped in eight different configurations, covering same-end and opposite-end arrangements from the left or right side. The connection type is a made-to-order specification, meaning it must be confirmed at the time of purchase because it cannot be changed after manufacturing. Specifying the connection code before ordering, and cross-checking it against both the roughed-in piping and the planned trim cover layout, prevents the most common installation problems on VLX jobs.