Boiling Point and Latent Heat of Vaporization

No latent heat is the amount of energy in the form of heat that the liquid gives off or absorbs to change state. Refrigerants are chosen because of their high latent heat capabilities, the amount of pressure need to hold the refrigerant in liquid form prior to evaporation, plus health and environmental issues.

The more pressure needed for refrigerants with same latent heat the less efficient the system

The boiling point of a liquid is the temperature at which it will "boil", or turn from liquid to vapor. The latent heat of vaporization of a liquid is the amount of energy required to convert a unit amount of the liquid from liquid to vapor.

Just a comment for all concerned with "boiling point" data. We all often use "boiling point" data rather cavalierly when quoting a boiling point. To quote a "boiling point" is meaningless unless one also quotes the pressure that the b.p. was measured at. Most text books use 760 mm (Hg) pressure, unless otherwise stated. As the pressure is reduced, a liquid tends to boil at lower temparatures.

I'm only agreeing with OZZB, really - and giving a little extra detail. The amount of heat that a refrigerant can transfer is the product of the specific heat and the mass that you can evaporate and transfer. It is the vapour pressure that effectively sets the density of the vapour you use to transfer heat and the force that drives the vapour. If the vapour pressure is very low, it becomes difficult to transfer much heat - even if the specific heat is high.

The latent heat of vaporization is the heat energy a liquid needs to absorb to transform from a liquid to a gas at its boiling point i.e. the liquid continues to absorb heat energy to evaporate without any corresponding increase in its temperature. That is the reason why boiling water at atmospheric pressure continues to maintain a temperature of 100 degrees Celcius when boiling despite the continuous addition of heat energy to the water.

I know this is kind of a dead topic, but...

The boiling point of a liquid is the temperature at which the liquid's vapor pressure equals the pressure above the liquid.

To be really picky, the pressure at the point of heating. If you had a really deep pot then water's boiling point would be higher than 100degC. At the top of a mountain it's lower.