In addition to several Radiant Floor Heating control strategies, there are two basic sources of energy: combustion and non-combustion, each with different control options.
The numerous control options must therefore be given careful consideration in terms of the functional requirements, economics, cost and budget.
- One thermostat is primarily used for controlling the operation of a pump. It is usually supplied from a constant temperature source. This is a similar function to a forced-air heating system.
- The second thermostat controls the fluid temperature with a constant circulation pump. This thermostat ensures a better performance than the first.
These control strategies should only be applied to a construction or utility building service.
Both of the above options can be improved by using an RFH thermostat that provides for some thermal lag compensation.
- The outdoor sensor control system instantly modifies the RFH operating temperature on the basis of the outdoor temperature. This control strategy will totally compensate for thermal lag.
- The outdoorIindoor sensorcontrol system functions almost identically as the above except for the addition of indoor temperature information.
As mentioned earlier, the term thermal lag is an RFH characteristic often misunderstood. An outdoor sensor control system can instantly compensate for an outdoor temperature change ahead of thermal lag. A thermostat can only respond to an indoor temperature change following thermal lag.
The basis of any heating system is to control the delivery of energy at the rate of loss. With forced-air systems, this is totally a function of air temperature. RFH systems can be controlled in the same way, but it is far more effective and efficient to use the outdoor temperature as the basis for control. Another RFH characteristic to consider is conduction delivery, as opposed to convection.