1. Field of the Invention
The present invention relates to an HVAC system (heating, ventilating, air-conditioning system) that includes a refrigerant circuit with an indoor coil having two coil slabs; the invention more specifically relates to a damper apparatus for determining whether airflow travels through the two coil slabs in parallel or series.
2. Description of Related Art
Typical split-system air conditioners and heat pumps comprise a refrigerant circuit with an indoor and an outdoor heat exchanger. Depending on the refrigerant's direction of flow through the circuit, the indoor heat exchanger may cool or heat a current of air, which is then conveyed to a comfort zone, such as room or other area within a building.
The indoor heat exchanger may comprise two sections, called coil slabs, which are often arranged in an A-shape. To heat or cool the air, a blower forces the air in parallel flow relationship across the two coil slabs. Such an airflow pattern provides several advantages, such as optimum system efficiency, maximum heating or cooling capacity, and plenty of airflow. In some applications, however, such a system has its drawbacks.
Many HVAC systems, for instance, exchange a considerable amount of indoor air with outside air to help keep the indoor air fresh. Unfortunately, the outdoor air may be humid, which can create a dank feeling within the building. The HVAC system, therefore, may require some means for reducing the humidity.
Another problem may exist with heat pumps operating in a heating mode. Although the heat pump may have sufficient capacity to maintain the building at a desired temperature, the heated air that a register discharges into a comfort zone may feel uncomfortably cool or drafty. This can be due to the supply air temperature being warmer than the room temperature but cooler than a person's body temperature. Consequently, the supply air temperature may need to be raised.
A further problem concerns systems that may operate the system blower with the refrigeration system de-activated. Examples of this would be for air circulation or when the refrigeration system is utilized with a combustion furnace. Here the resistance to airflow by the indoor heat exchanger becomes an undesirable system efficiency loss.