Poaceae have hollow stems called culms plugged at intervals by solid leaf-bearing nodes. Grass leaves are nearly always alternate and distichous (in one plane), and have parallel veins. Each leaf is differentiated into a lower sheath hugging the stem and a blade with entire (i.e., smooth) margins.oaceae have hollow stems called culms plugged at intervals by solid leaf-bearing nodes. Grass leaves are nearly always alternate and distichous (in one plane), and have parallel veins. Each leaf is differentiated into a lower sheath hugging the stem and a blade with entire (i.e., smooth) margins.
Air conditioning system components consisting of Condensing Unit, Evaporator Coil, Refrigerant line. How air conditioning works is kind of a mystery to many of us. Furnaces are easy to understand, they heat air and blow it around your home in ductwork.
Air Handlers. An HVAC air handling unit (also called an AHU) is the indoor part of your heating and cooling system. An air handler circulates both cool and hot air, depending on the season. When properly matched with a heat pump or air conditioner, an air handler will help you maximize the overall efficiency of your HVAC system.