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.
The cooling capacity of an air conditioner is measured in tons. In regards to cooling, 1 ton is equal to 12,000 BTU's (British Thermal Units). A standard air conditioner ranges in size, from smallest to largest: 1  18 = 1.5 Ton (18,000 BTU). 2  24 = 2.0 Ton (24,000 BTU).