With radiant floor heating, every inch of your home feels comfortable. Even bathrooms, entryways and basements are as warm and cozy as the living room — that’s because radiant floor heating offers the most even, energy-efficient temperatures throughout the entire home.
Forced Air and Radiant Heat comparison

Because hot air rises to the ceiling, forced-air heating systems are significantly inefficient and provide uneven temperatures throughout a home. Radiant floor heating systems circulate warm water through crosslinked polyethylene (PEX) tubing located beneath the floor — keeping the heat at your feet. Radiant floor heating systems work with all types of flooring surfaces, including carpet, wood, tile, stone, laminate and concrete. And because radiant systems work in “zones”, you can adjust temperatures in different areas of the home at the same time. So unoccupied rooms have a different temperature than occupied rooms — making the system even more energy-efficient. Typical design room setpoints with radiant heating 68°F (20°C) for heating reducing the demands placed on the air-side system.
Radiant System Installation Options
Radiant systems are configured in one of two basic ways. High mass systems incorporate the mass of the building, with tubing embedded in structural concrete. Low mass systems use tubing embedded in surface-mounted ceiling, floor or wall panels. Typically, the same panels are used for heating and cooling functions. Installation options for high and low mass systems can include the following:
High Mass Systems:
On-grade with expansion joint
Concrete on metal decking
Slab-on-slab over high density insulation
Concrete on pre-stressed decking
Low Mass Systems:
Poured-floor underlayment
Quik Trak® panels over wood subfloor
Uponor aluminum heat emission plates
Quik Trak® panels wall application
Radiant System Components
Manifolds
Supply and return water connections are made to distribution manifolds, which connect to the floor tubing. By convention, the supply manifold is normally installed below and in front of the return manifold. Space permitting, the manifolds are typically installed in a reverse-return arrangement, with supply water connecting on one side of the assembly and the return water connecting on the opposite side.
Engineered Polymer (EP) Manifold
Engineered Polymer (EP) Manifold
PEX tubing
Crosslinked polyethylene (PEX) tubing is specially designed plastic tubing with distinctive properties that make it ideal for radiant floor heating and plumbing systems. Uponor produces PEX-a tubing, which is considered the superior type of PEX.
PEX tubing
Local Zone Control
Individual loops can be controlled with thermal actuators mounted directly on the manifold. The valves and actuators are controlled by space temperature sensors. It is possible to have local zone control within each mixed water temperature zone.
While the below piping arrangements will dictate target water temperature, zone valves can add local control by controlling water flow. Depending on the size of the local zone, zone valves can be added to control a group of manifolds or a single manifold.
Motorized Valve Actuator and Zone Valve
Thermal Valve Actuator
Room Thermostats/Sensors
Regardless of the choice of temperature and humidity sensing for feedback or feed forward, the receiving controller will process “if/then” logic to control the flow entering the occupied zone via the water temperature zone by regulating valves and circulators. The sensing should always take place to best represent the controlled element without interference from other aggravating influences. For example, outdoor sensors for heating controls should best represent the outdoor dry bulb temperature without interference from solar gains which would incorrectly feed forward the wrong signal to the controller.
Wireless Digital Thermostat
Control Zoning System is for use with underfloor heating installations and combines comfort, user friendliness and temperature control for each individual room of a home. The system consists of a base unit, thermostats and actuators. The base unit manages the operation of the actuators when the thermostats detect a demand for the heating. The system is controlled by different types of thermostats. Thermostats communicate with the base unit by radio link.
Local control is defined as a thermostat in a room that determines when the room is not within an acceptable margin of the setpoint and sends a signal that heating is needed.
Radiant Heating: Energy and comfort comparison
Radiant heating provides greater thermal comfort at a lower temperature set point than forced-air heat.
Energy savings with a radiant heating system can range from 20-40% over traditional forced-air systems.
Typical construction methods used in commercial radiant heating installations.
Quick-quote procedure
- Determine parameters (A)
- For each area, calculate total tubing (D).
- Based on tubing required, estimate the number of loops (E). Make sure to account for leader lengths.
- Based on number of loops, determine number of manifolds (F). Make sure to check flow rates.
- Determine coils to minimize waste (I).
- Size manifold cabinets (J).
- Include accessories in quote
- Delta T = ABS (space temperature-controlled surface temperature)
- Assumes that space temperature is close to or equal to operative temperature
- Surface area = active area
- Does not include direct solar absorption
- Maximum loop lengths determined by pressure drop. Goal PD < 10 ft.
- Pressure drops can vary greatly based on operating temperature, flow rate, and glycol percentage.
- Be sure to include leader tubing
Sizing and Locating Manifolds
Supply and return water connections are made to distribution manifolds, which connect to the floor tubing. By convention, the supply manifold is normally installed below and in front of the return manifold. Space permitting, the manifolds are typically installed in a reverse-return arrangement, with supply water connecting on one side of the assembly and the return water connecting on the opposite side.
Design software we use simplifies and increases efficiencies for completing a radiant heating design and/or quotation. Users can perform a quick room-by-room heat loss by entering data in cells. This format will provide heat-loss information, surface and water temperatures, and flow and pressure-loss calculations.
THE RADIANT READY
The Radiant Ready 30ETM (A3503000) is a complete radiant mechanical room designed in a compact, preassembled, easy-to-install panel. The unit, which includes a boiler, manifold, pump, expansion tank, pressure-relief valve, isolation valves, thermostat and air vent, is already wired, plumbed, tested and ready to be installed. Simply attach the panel to a wall, connect the radiant loops, attach the thermostat and connect the 240V electrical power.