
Heating ventilation and air conditioning
534
with the main magnetic eld causing it to warp. Figure 13.30 shows this eld
warp diagrammatically. This phenomenon was also used in some very early
generators as a way of controlling output.
13.4.4 Refrigerant developments
The ideal refrigerant has good thermodynamic properties, is unreactive
chemically, and safe. The desired thermodynamic properties are a boiling
point somewhat below the target temperature, a high heat of vaporization,
a moderate density in liquid form, a relatively high density in gaseous form,
and a high critical temperature. Since boiling point and gas density are
affected by ...