Radiant Heating and Cooling
Radiant floor heating systems supply heat directly to the floor or walls in a home or building. This depends largely on radiant heat transfer, which is the natural transfer of heat to objects of a cooler temperature. Radiant floor heating is more efficient than forced-air heating because it avoids thermal losses associated with improper duct design and insulation. The greatest benefit of radiant heat is comfort. Every object in a room becomes warm and contributes to the overall atmosphere so that the living space maintains an even temperature, with no air currents, blowing dust, or cold spots, and radiant heat doesn't dry out the air, like forced air systems. For a discussion on how the hydronic radiant system is integrated with solar hot water collectors and a geothermal heat pump, visit the Integrated Systems section.
Radiant cooling is an underutilized technology because of potential condensation if the system is left to run unchecked. This is especially true in humid climates. However, in semi arid climates such as Colorado, radiant cooling is easily applicable with the simple installation of a dew point sensor to monitor condensation potential. On the rare event that conditions are favorable for condensation on the system, the sensor merely shuts down the cooling to prevent this. See below for a description and resource for the dew point sensor.
Radiant cooling provides an energy and cost saving alternative solution to central AC, when combined with a water-to-water geothermal heat pump. A typical home which utilizes radiant heating, most likely will have to install ductwork and purchase a central air unit in order to supply cooling for the home. Enabling heating and cooling with a water-to-water geothermal heat pump avoids these additional costs and thermal losses associated with installation of a central forced air system. EEC's platinum LEED home will provide a demonstration of the applicability of radiant cooling in Colorado.
Platinum LEED Home Hydronic Radiant System
EEC’s showcase home incorporates hydronic radiant heating and cooling in combination with solar hot water collectors and a water-to-water geothermal heat pump. The majority of the home has high mass in floor radiant heating and cooling in which tubing is laid in the floor in gypcrete. Some other features of the radiant system include: Garage, driveway, and porches all have radiant in the concrete to provide snow and ice melt and controlled through sensors and switches; Hot water radiant behind bathroom mirrors will prevent condensation during showering; Radiant tubing in walls to be circulated with cold water, creating a "cool pantry" and wine cellar. See pictures below.
Radiant tubing is laid in zones throughout the entire home.
The tubing is then covered with Therma-Floor, a gypsum underlayment for high mass radiant floors.
View of downstairs radiant tubing.
Radiant zone controls.
Whole house radiant zone system controls.
Radiant floor tubing being installed on the ground level of the home. Concrete is then poured over the tubing.
Radiant heating installed in bathroom wall. The floor space is insufficient to provide enough BTUs for the space, so radiant is installed in the wall to add heat..
Radiant tubing is being installed on the front porch and driveway of the home where excess hot water from the solar hot water system will be used for radiant snow melt.
Above, workers pour concrete over radiant tubing installed on the front porch.
Below, we list the products and controls that are incorporated into EEC's radiant floor heating and cooling system.
Therma-Floor® is a gypsum underlayment designed to pour over hot water tubes or electric heating cables. It acts as the thermal mass for any radiant floor system. Therma-Floor encases the tubes or cables in crack resistant, noncombustible gypsum. Its special formula resists breakdown to 150ºF (66ºC). And because it's poured only 1-1/4" (32 mm) thick, the heating system is more responsive and more comfortable.
Now always a "green" building material, Therma-Floor is an ideal solution for sustainable building projects.
GE Telaire Vaporstat 9002 Infrared Dewpoint Sensor
The Vaporstat ™ is the first commercial infrared dew point sensor that directly measures absolute humidity by counting the number of water molecules in air. The sensor display provides a user selectable display of grains/lb of dry air or °F dew point. The Vaporstat ™ is designed for direct in-duct or wall mounting applications and is compatible with all of Telaire's accessory enclosures. The Vaporstat ™ provides a similar performance to a chilled mirror, but is a fraction of the cost and requires considerably less adjustment and maintenance.