Floor Heating Heat Loss Calculator
WarmlyYours floor heating systems can be an effective primary heat source. However this effectiveness can vary given such variables as climate, insulation and position of the room that you want to heat in your home. This innovative online tool can help you determine if the room you would like to heat is a good candidate.
Click the button below to find out whether our floor heating systems can be used as the primary source of heat in your room, create a new project/room and select the Heat Loss Calculation option after you see your instant quote options.
Heat Loss CalculatorSpecial Note:
When setting the temperature of your floor heating system, ensure compliance with the floor covering manufacturer's required maximum temperature limit, if applicable to your floor covering type. Due to some flooring manufacturer's maximum temperature limitations, some floor covering types may not serve as an optimal choice for a primary/sole heating source.
Frequently Asked Questions
Showing all 10 questions
The temperature of your floor can range anywhere between 75°F to 95°F. The floor's actual temperature will depend on a number of factors including the amount of heat loss that the room experiences as well as the room’s configuration. For instance, the warmth contained in a two story entry way would likely be less than that of a smaller, more enclosed area such as a bathroom. In a bathroom that is located on the second floor of your home or over another floor in your home that is typically heated, the temperature of your heated floor should easily reach a comfortable temperature of 85 degrees Fahrenheit, if the electric floor heating system is installed correctly. For the heat loss calculation for your specific room, you can access the Heat Loss Calculator or you can call us at (800) 875-5285 and a Customer Service Representative will make the calculation for you.
Yes, radiant floor heating can be used as a primary heat source in well-insulated homes, particularly in moderate climates. However, most North American homes use it as supplemental heating to enhance comfort and reduce reliance on forced-air systems.For primary heating, you need:
- Proper insulation (walls, windows, attic)
- Adequate watt density (typically 15 watts/sq.ft. or higher)
- Coverage across 80%+ of floor area
- Climate-appropriate system design
Not sure if your home qualifies? Use our free Heat Loss Calculator to determine if radiant floor heating can serve as your primary heat source. This tool calculates your room's heat requirements based on insulation, climate, and construction details.WarmlyYours also offers free consultation with our engineering team to assess whether your home is suitable for primary heating. Our 24/7 support and 26 years of experience across 300,000+ installations ensure you get the right system for your needs.
Measure each surface that touches the outdoors — walls, windows, doors, ceiling, and floor — divide each area by its R-value, then multiply by the difference between your desired indoor temperature and your design outdoor temperature. Add the results for the room’s total BTU/hr loss. Our free Heat Loss Calculator handles the math for you.
One watt equals about 3.412 BTU per hour. TempZone™ Flex Rolls, Easy Mats and Shower Mats, and TempZone™ Cable at 3-inch spacing, deliver 15 watts per square foot: about 51 BTU per hour for every square foot of heated floor. Environ™ delivers 12 watts per square foot, about 41 BTU per hour. For any product, multiply the wattage on its label by 3.412.
Only heated floor counts, and heating can’t run under cabinets or fixtures: 100 square feet of 15-watt heating produces about 5,100 BTU per hour. Compare that with your room’s heat loss.
Yes. Below-grade walls and slabs lose heat to soil that stays far warmer than winter air, so a basement often has lower heat loss than a comparable room upstairs — which makes radiant floor heating a strong candidate for primary heat. Insulate under the slab and at the rim joists, and account for egress windows and any walk-out walls in your calculation.
Then the floor alone won’t hold your target temperature on the coldest days. You have two options: reduce the heat loss — add insulation, upgrade glazing, seal air leaks — and re-run the calculation, or use radiant floor heating as supplemental comfort heat alongside your existing system. Either way, our engineers can review your numbers and recommend a system at no cost.
Have these details ready before you start:
- Room length, width, and ceiling height
- Wall, ceiling, and floor construction or insulation R-values
- Window and door sizes plus glazing type (single, double, or triple pane)
- Your city or design outdoor temperature
- The indoor temperature you want to maintain
Estimates are fine — you can adjust inputs and re-run the calculation as often as you like.
A heat loss calculation measures how many BTUs per hour a room loses through its walls, windows, doors, ceiling, and floor on the coldest day of the year. Compare that number to your radiant system’s heat output: if the floor produces more BTUs than the room loses, it can heat the space on its own.
A heat loss calculation is essential to ensure your radiant system produces more BTUs than your room loses to the outside environment. This professional assessment guarantees your system has the necessary power to serve as your primary heat source, providing peace of mind during record-breaking cold.
More output lets the floor make up more of a room’s heat loss. TempZone™ Flex Rolls, Easy Mats and Shower Mats, and TempZone™ Cable at 3-inch spacing, deliver 15 watts per square foot: up to 25% more heating power than the nearest competitor’s systems, and enough for primary or supplemental heat. Cable at 4-inch spacing, about 11 watts per square foot, is for supplemental heat only.
Whether floor heating can be a room’s only heat source depends on that room’s heat loss. An uninsulated concrete slab, for example, absorbs part of the heat, so insulating over it helps. WarmlyYours can calculate your room’s heat loss before you decide.
