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.
Complete Your HVAC System. The most common central air system is a split system, which includes an indoor unit and an outdoor unit. An air conditioner is an outdoor unit, usually installed in conjunction with a furnace or air handler.