- nickel alloys
- night
- nitrogen refrigeration
- nitrogen trap
- nitrogen vapour
- nodal
- noise immunity
- noise meter
- noise-free
- noise-proofness
- noiseless
- nominal temperature
- nominal ton
- network constant
- network flow
- network termination
- neutral state
- neutron capture
- neutron number
- Nichols chart
- nimbus
- nitrogen atmosphere
- nitrogen liquefier
- nitrogen pulldown
- nitrogen refrigerator
- nitrogen tank
- nonadiabatic
- nonblack
- nonblocking
- noncyclic variation
- nonelectrified
- nonfreezing
- nonfusible
- nonlinear materials
- nonlinear viscoelasticity
- nonlubricated compressor
- nonode
- nonperiodic variation
- nonpolar
- nonpriming evaporator
- nonrefrigerated section
- nonsalient pole
- nonselective absorption
- nonsteady temperature
- nontoxic refrigerant
- nonzero
- normal atmosphere
- normal bend
- no-background
- no-load
- noble
- nodal analysis
- nodal line
- node law
- node voltage
- noise absorption
- noise control
- noise curve
- noise generation
- noise tolerance
- noise-killer
- noise-proof
- nonanalytic
- noncapacity
- noncombustible insulation
- noncondensable gas
- noncondensing
- nondimensional number
- nonfrozen state
- nonimpregnated paper
- nonlinear susceptibility
- nonluminous
- nonmagic nucleus
- nonmetallic
- nonohmic
- nonoverlapping
- nonpolarized
- nonporous
- nonresonant
- nonreversible
- nonrigid
- nonself-quenching
- nonspherical
- nonstationary flow
- nonturbulent
- nonviscous
- noise damper
- noise generator
- noiseless chiller
- nominal refrigeration
- Nominal value
- nominal wavelength
- nonabsorbing
- nonazeotropic mixture
- nonbleeding cable
- noncentral
- noncoincident demand
- noncondensables
- nondestructive
- nondiagonal element