Radiant heating/cooling systems can be divided into:   Underfloor and wall heating systems often are called low-temperature systems. Since their heating surface is much larger than other systems, a much lower temperature is required to achieve the same level of heat transfer. This provides an improved room climate with healthier humidity levels. The maximum temperature of the heating surface can vary from depending on the room type. Radiant overhead panels are mostly used in production and warehousing facilities or sports centers; they hang a few meters above the floor and their surface temperatures are much higher. In the case of heating outdoor areas, the surrounding air is constantly moving. Relying on convection heating is in most cases impractical, the reason being that, once you heat the outside air, it will blow away with air movement. Even in a no-wind condition, the buoyancy effects will carry away the hot air. Outdoor radiant heaters allow specific spaces within an outdoor area to be targeted, warming only the people and objects in their path. Radiant heating systems may be gas-fired or use electric infrared heating elements. An example of the overhead radiant heaters are the patio heaters often used with outdoor serving. The top metal disc reflects the radiant heat onto a small area. Radiant cooling is the use of cooled surfaces to remove sensible heat primarily by thermal radiation and only secondarily by other methods like convection. ASHRAE defines radiant systems as temperature-controlled surfaces where 50% or more of the design heat transfer takes place by thermal radiation. Radiant systems that use water to cool the radiant surfaces examples of hydronic systems. Unlike “all-air” air conditioning systems that circulate cooled air only, hydronic radiant systems circulate cooled water in pipes through specially-mounted panels on a building's floor or ceiling to provide comfortable temperatures. There is a separate system to provide air for ventilation, dehumidification, and potentially additionally cooling. Radiant systems are less common than all-air systems for cooling, but can have advantages compared to all-air systems in some applications. Since the majority of the cooling process results from removing sensible heat through radiant exchange with people and objects and not air, occupant thermal comfort can be achieved with warmer interior air temperatures than with air based cooling systems. Radiant cooling systems potentially offer reductions in cooling energy consumption. The latent loads (humidity) from occupants, infiltration and processes generally need to be managed by an independent system. Radiant cooling may also be integrated with other energy-efficient strategies such as night time flushing, indirect evaporative cooling, or ground source heat pumps as it requires a small difference in temperature between desired indoor air temperature and the cooled surface.