Quiet Portable Heater

portable
A version of something, such as a small lightweight television or computer, that can be easily carried
a small light typewriter; usually with a case in which it can be carried
easily or conveniently transported; "a portable television set"
A small transportable building used as a classroom
of a motor designed to be attached to the outside of a boat's hull; "a portable outboard motor"

heater
A person or thing that heats, in particular a device for warming the air or water
A heater is object that emits heat or causes another body to achieve a higher temperature. In a household or domestic setting, heaters are usually appliances whose purpose is to generate heating (i.e. warmth). Heaters exists for all states of matter, including solids, liquids and gases.
A conductor used for indirect heating of the cathode of a thermionic tube
A fastball
device that heats water or supplies warmth to a room
fastball: (baseball) a pitch thrown with maximum velocity; "he swung late on the fastball"; "he showed batters nothing but smoke"

quiet
quietly: with little or no activity or no agitation (`quiet' is a nonstandard variant for `quietly'); "her hands rested quietly in her lap"; "the rock star was quietly led out the back door"; "sit here as quiet as you can"
characterized by an absence or near absence of agitation or activity; "a quiet life"; "a quiet throng of onlookers"; "quiet peace-loving people"; "the factions remained quiet for almost 10 years"
lull: a period of calm weather; "there was a lull in the storm"
(of a place, period of time, or situation) Without much activity, disturbance, or excitement
Making little or no noise
Without being disturbed or interrupted