Part VII: In-Seat Climate Control System, Technical Discussion
By John-Paul McGovern, Ph.D., chief of research and technology, USSC Group, Inc.
This is the seventh installment in a series of articles discussing recent technology advancements in fire apparatus seat systems. Previous articles have discussed technology advancements in first responder seat systems, transition of technology from complimentary markets, and seat system serviceability. The present article is a follow-on to the previous article in the series and will discuss the integration of an occupant heating and cooling system in more technical detail.
The cooling and heating system in Valor seats uses Tempronics’s Contact Climate System to provide thermal comfort performance compared with what is currently being used in luxury automotive vehicles. This seat system is able to provide thermal comfort performance through the uniquely engineered and patented “Climate Ribbon” used in Tempronics’s Contact Climate Thermal Comfort System.
The Climate Ribbon is the engine behind the system performance. This braided wire ribbon is a thermoelectric system, but instead of being small and compact like traditional thermoelectric systems used for forced air cooling and heating, the Climate Ribbon uses “distributed” thermoelectric nodes along the entire length of the braided wire ribbon. The Climate Ribbon is integrated into the seat just under the seat system upholstery such that it interfaces directly with the occupant across the occupant seat surface interface. Each of the thermoelectric nodes acts as a small heat pump, pumping heat into or out of the ribbon that is in contact with the occupant seated surface. This direct contact cooling and heating is called “Contact Climate.”
There are several differences between this seat cooling and heating system and traditional forced-air thermal comfort systems:
- Having consistent, even and direct contact between the Climate Ribbon and the occupant seated surface allows the thermal effect to be felt much faster and more intensely.
- Even in severe environmental conditions we achieve thermal comfort quickly. Since the ribbon is in direct contact with the occupant, the system doesn’t have to cool or heat the entire seat structure before the occupant feels cool. With traditional forced-air systems, the air has to flow through the seat structure and takes time to cool or heat the seat structure before it can start cooling or heating the occupant.
- This system provides full and even coverage across the occupant seated surface interface to provide thermal management where it is needed most. Conversely, the perforations in the seat cover gets blocked by the occupant with a forced-air system, so thermal management is uneven and not effective at the occupant seated surface.
- Muscle tissue under pressure from sitting for extended periods experiences oxygen deprivation, resulting in aches and fatigue. The even contact cooling provides maximum cooling where it is needed most and restores oxygenation to the muscle tissues, reducing achiness and fatigue.
The Tempronics Contact Climate technology used in Valor seat systems also consumes less power than other systems. How do we provide all this performance at reduced energy consumption? Department of Energy studies show it takes less energy to keep the occupant comfortable with the Tempronics Contact Climate system than it does by using the traditional vehicle HVAC alone. This system uses about half the energy consumed by a traditional forced-air seat climate system. The same Climate Ribbon both heats and cools the occupant directly. Most forced-air systems must use a resistive wire heating pad in addition to the forced air heat because the forced air heat is so ineffective.
Faster, more intense, and thorough even coverage define Valor seat systems’ thermal comfort performance. This allows first responders to feel their best and perform at their best—not just to and from, but at the scene. This thermal comfort seat can also be used to help manage core body temperature and keep firefighters on task at the scene when managing and working from the rescue equipment.
For more information, visit: http://landing.penngage.com/ussc-valor/