An AC system has many components: compressor, condenser, receiver dryer, evaporator, and hoses. The compressor, the âheartâ of the carâs air conditioning system works like a pump taking refrigerant, (R-12 in older cars, R-134a in 1995 and newer cars) and pressurizing it, passing it along to the evaporator. The AC compressor has several moving parts (including pistons and valves).
Quick Answer. According to WebMD, a normal blood pressure is lower than 120/80. This means that the systolic number is 120 or lower, and the diastolic number is 80 or lower. The systolic number measures artery pressure when the heart contracts. The diastolic number measures artery pressure between heartbeats.
She says regular blood pressure checks should start at age 3, but says that even younger children can have hypertension and should be treated for it. An adult is considered to have high blood pressure when the top number of a blood pressure reading (systolic pressure) is more than 140 mm Hg or when the lower number of a blood pressure reading is more than 90 mm Hg (diastolic pressure).