Possibilities and limitations of radiant floor cooling

Conference · Wed Dec 31 04:00:00 EST 1997

OSTI ID:345210

Olesen, B W ^[1]

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1. D.F. Liedelt Velta GmbH, Norderstedt (Germany)

To evaluate the usefulness of radiant floor cooling, it is important to take into account comfort, cooling capacity, control, and design. One limiting factor is the floor surface temperature. In spaces with seated or standing people, the floor temperature should not be lower than 19 C (66 F) for comfort reasons. For higher activity levels, a lower floor surface temperature may be acceptable and the limitation will then be the dew-point temperature in the space. The heat exchange coefficient between a cooled floor and the room is typically around 7 W/m{center_dot}{degree}C (1.23 Btu/ft{sup 2}{center_dot}h{center_dot}{degree}F), where 5.5 W/m{sup 2}{center_dot}{degree}C (0.97 Btu/ft{sup 2}{center_dot}h{center_dot}{degree}F) is radiant heat transfer. In spaces with occupants who are mostly seated, the upper comfort limit for the operative temperature in summer is 26 C (79 F). This means that, based /on the heat exchange between the floor surface and the room, a maximum cooling capacity for a floor system is about 50 W/m{sup 2} (16 Btu/h{center_dot}ft{sup 2}). In several spaces, such as atria, entrance halls, or other spaces with window facades, there will often be a lot of direct sunshine on the floor. In these cases, the cooling capacity is significantly higher and may reach 100 to 150 W/m{sup 2} (32 to 47 Btu/h{center_dot}ft{sup 2}). The cooling capacity, however, also depends on the floor construction, distance between tubes, water flow rate, and floor covering. The influence of these parameters is discussed in this paper, and a method for dimensioning based on a European standard is presented.

• OSTI ID: 345210
• Report Number(s): CONF-9702141--
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
BUILDINGS
CAPACITY
COOLING SYSTEMS
FLOORS
RADIANT HEAT TRANSFER
RADIATIVE COOLING
THERMAL COMFORT