Using multiple electric radiant floor heating mats
When space calculations are complete, the size of the heated area in sq. ft is used to select a proper size heating mat as listed above. Often, the sq. ft number does not precisely match the mat size and it may be necessary to use (2) or more mats to cover the entire area.
NOTE: For 120V systems, the total combination of mats selected must not exceed 150 sq. ft per thermostat. For 240V systems, radiant heating mats allow for a maximum of 300 sq. ft coverage per single thermostat. Controls for larger areas are also available - inquire for details.
When space calculations yield 57 sq. ft, a mat with 50 sq. ft coverage may be insufficient, and a floor heating mat with 60 sq. ft coverage may be too big and leave excess heating cable. As a typical solution, a combination of (2) radiant floor heating mats cane be used: (1) with 15 sq. ft coverage and (1) with 50 sq. ft coverage, totaling 55 sq. ft coverage - an optimal solution for the example provided.
An area with a total of 126 sq. ft will require a combination of several mats, as the largest radiant heating mat covers only 100 sq ft. Properly selected mat sizes would be (1) 15 sq. ft mat and a combination of any (2) mats totaling 110 sq. ft of coverage, i.e. 60+50, 70+40, 80+30, etc. - whichever works best for the specifics of the given project.
Contrary to the Example 1, areas such as 83, 44 & 61 sq ft most often will not require the use of a 15 sq ft mat to leverage the extra 1-4 sq. ft of space. Slightly offsetting the heating mat from the perimeter of the heated area (cabinets, walls, tubs, toilets, showers, etc.) is often all is needed to use a single mat for the entire project. Alternatively, consider using a "buffer" area as described on Sizing page.
Selecting the right thermostat
Best of the best
- all thermostats we sell are genuine Honeywell/Aube or OJ Microline brands, which set industry standard and are well known for quality, safety and reliability. Models we offer include:
Honeywell/Aube TH115-AF-120S - regular 120V model
Honeywell/Aube TH115-AF-240S - regular 240V model
Honeywell/Aube TH115-AF-GA - model w/ built-in 5mA GFCI (120/240V dual voltage compatible)
OJ Microline UDG-4999 - model w/ built-in 5mA GFCI (120/240V dual voltage compatible)
All of the above listed are 7-day programmable, floor sensing type thermostats:
- selecting a programmable thermostat grants user the ability to control the operating time and temperature of the system. Typical savings vs. non-programmable thermostat can be in the 10-30% range.
Floor sensing ability
- the vast majority of thermostats are designed for sensing the temperature of the surrounding (ambient) air, and if used in conjunction with an electric floor heating system, will delay system response, resulting in longer system start-ups and cool-downs. Floor sensing thermostats include the option of connecting a floor sensor (included with all thermostats we sell) and provide instant and accurate temperature readings resulting in higher levels of comfort.
Built-in GFCI protection
(available only on GFCI models) - this safety feature is highly recommended for installation in wet areas, especially showers, kitchens and saunas and offers added protection against the unlikely event of electrical shock as a result of damaged electrical cable.
Using a backup floor sensor
Floor sensors we sell are designed to last for the lifetime of the electric floor heating system and outperform any other known brands. The unlikely event of sensor failure may disrupt the normal operation of the system, or cause it to malfunction. For this reason, installation of a backup sensor if highly recommended to avoid removal/disassembly of flooring and consequent repairs. If a secondary floor sensor is undesirable, installers may choose to use conduit piping as housing for the floor sensor, giving the flexibility to replace it without removing the finished flooring.
HeatTech Mats - Installation Manual (pdf)
TH115-AF-120S and TH115-AF-240S - Installation Manual (pdf)
TH115-AF-GA - Installation Manual (pdf)