Even a new, minimum efficiency air conditioner or furnace can be a significant jump in efficiency. The old furnace in your basement may only be originally rated at 60% to 70% AFUE. In order to comply with national regulations, furnaces manufactured today have to be rated at a minimum of 80% AFUE.
dipole - a pair of equal and opposite electric charges or magnetic poles separated by a small distance. couple - (physics) something joined by two equal and opposite forces that act along parallel lines. electric dipole, electric doublet - a dipole with equal and opposite electric charges.
HCl molecules, for example, have a dipole moment because the hydrogen atom has a slight positive charge and the chlorine atom has a slight negative charge. Because of the force of attraction between oppositely charged particles, there is a small dipole-dipole force of attraction between adjacent HCl molecules.The dipole-dipole interaction in HCl is relatively weak; only 3.3 kJ/mol.(The covalent bonds between the hydrogen and chlorine atoms in HCl are 130 times as strong.) The force of attraction between HCl molecules is so small that hydrogen chloride boils at -85.0 o C. Dipole-Induced Dipole Forces.nduced Dipole-Induced Dipole Forces. Neither dipole-dipole nor dipole-induced forces can explain the fact that helium becomes a liquid at temperatures below 4.2 K. By itself, a helium atom is perfectly symmetrical.