SunTouch UnderFloor is a safe and efficient radiant electric floor heating system retrofitting an existing cold floor with heat without disturbing the existing floor covering. UnderFloor is for interior applications only and is intended only for installation under an existing wood subfloor (accessed from underneath via crawl space, basement, or garage ceiling) in residential and light commercial installations.

Insulation is ESSENTIAL after mats are installed into joist spaces. We recommend SunTouch UnderFloor Mats be installed in all areas where floor warming is desired; the floor is only warm directly over an installed mat. If UnderFloor is being installed to heat the space, first perform a heat loss calculation to determine the amount of BTUs required to heat the space.

Details for this size:

• 16" wide for use with 16" OC joists = 14-1/2" space between joist sides
• 16 feet Long
• 240 VAC
• Amps = 0.8
• Dual Wire Heating element made of Oxygen free copper, Individually insulated and grounded end-to-end
• UL Listed for safety with Zero EMF
• 34 BTUs/SF/Hr = 10 Watts per Sq Ft
• 10 Foot Armored & Fully Grounded 3-wire power lead color coded to NEC specs

The SunTouch UnderFloor Heating Mats unique design is composed of a proprietary dual element heating cable, a foil radiator surface and an armored power lead for connection to the Thermostat Control. Refer to the Installation Manual for helpful design guidelines.

UnderFloor is available in 3 widths to fit most joist spaces in North America; 16, 12, and 19.2 inches OC (on center). Mats are available in either 120 or 240 VAC. Select the mat length to fit into each joist space available. Multiple mats can be used to fill a larger area, however they must be wired together in parallel (not in series) if they are to be connected to the same control.

NEVER combine 120-VACmats with 240-VAC mats on the same circuit. All mats lead back to a junction box see photo here. Each mat is designed to be installed in only one joist bay. The mats cannot be cut shorter to fit a shorter joist bay and cannot be modified in any way to fill multiple joist bays.

SunTouch UnderFloor is designed to deliver approximately 10 watts per Sq Ft. and 34 BTU/Hr/Sq.Ft. of heated floor area. This assumes the mats are installed per the Installation Manual, including the use of proper insulation techniques. The output will be greatly diminished without proper insulation. The temperature of the warm floor is dependent on how well the floor is insulated, as well as the insulating value of the flooring materials. If the joist space is sealed against air leakage, the exterior rim joists are insulated, and the underneath side of the floor is insulated, most floors can be heated up to 15 degrees F warmer than they would be without UnderFloor Heat Mats.

Due to the insulating value of carpet & pad, carpeted floors may not achieve the same temperature rise. While we have many satisfied UnderFloor customers, we cannot commit to a specific temperature increase and no representations are made regarding the performance of any system. SunTouch UnderFloor can even be used to heat a room, as well as warm the floor, provided the heat loss of the room falls within the mats capabilities. A professional must determine if the output from the SunTouch UnderFloor is enough to match the heat loss of the structure. Download a Heat Loss Calculation Form here.

Additional Information

SunTouch UnderFloor Mats fit under your existing floor into your Joist Bays. 16" x 16' Length heats 21.28 Sq Ft., 240v, 0.8 amps each.

See UnderFloor Installation Manual

UnderFloor FAQ