Central heating

A central heating system provides warmth to the whole interior of a building (or portion of a building) from one point to multiple rooms. When combined with other systems in order to control the building climate, the whole system may be an HVAC (heating, ventilation and air conditioning) system.

Overview

Central heating differs from space heating in that the heat generation occurs in one place, such as a furnace room in a house or a mechanical room in a large building (though not necessarily at the "central" geometric point). The heat is distributed throughout the building, typically by forced-air through ductwork, by water circulating through pipes, or by steam fed through pipes.

The most common method of heat generation involves the combustion of fossil fuel in a furnace or boiler. Increasingly, buildings utilize solar-powered heat sources, in which case the distribution system normally uses water circulation.

In much of the temperate climate zone, most new housing has come with central heating installed since the Second World War, at least. Such areas normally use gas heaters, district heating, or a oil-fired system, often using forced-air systems. Steam-heating systems, fired by coal, oil or gas, are also used, primarily for larger buildings. Electrical heating systems occur less commonly and are practical only with low-cost electricity or when ground source heat pumps are used. Considering the combined system of central generating plant and electric resistance heating, the overall efficiency will be less than for direct use of fossil fuel for space heating.

System

A system is a set of interacting or interdependent component parts forming a complex/intricate whole. Every system is delineated by its spatial and temporal boundaries, surrounded and influenced by its environment, described by its structure and purpose and expressed in its functioning.

The term system may also refer to a set of rules that governs structure and/or behavior. Alternatively, and usually in the context of complex social systems, the term is used to describe the set of rules that govern structure and/or behavior.

Etymology

The term "system" comes from the Latin word systēma, in turn from Greek σύστημα systēma: "whole compounded of several parts or members, system", literary "composition".

History

According to Marshall McLuhan,

"System" means "something to look at". You must have a very high visual gradient to have systematization. In philosophy, before Descartes, there was no "system". Plato had no "system". Aristotle had no "system".

In the 19th century the French physicist Nicolas Léonard Sadi Carnot, who studied thermodynamics, pioneered the development of the concept of a "system" in the natural sciences. In 1824 he studied the system which he called the working substance (typically a body of water vapor) in steam engines, in regards to the system's ability to do work when heat is applied to it. The working substance could be put in contact with either a boiler, a cold reservoir (a stream of cold water), or a piston (to which the working body could do work by pushing on it). In 1850, the German physicist Rudolf Clausius generalized this picture to include the concept of the surroundings and began to use the term "working body" when referring to the system.

Home directory

A home directory is a file system directory on a multi-user operating system containing files for a given user of the system. The specifics of the home directory (such as its name and location) is defined by the operating system involved; for example, Windows systems between 2000 and 2003 keep home directories in a folder called Documents and Settings.

Description

A user's home directory is intended to contain that user's files; including text documents, music, pictures or videos, etc. It may also include their configuration files of preferred settings for any software they have used there and might have tailored to their liking: web browser bookmarks, favorite desktop wallpaper and themes, passwords to any external services accessed via a given software, etc. The user can install executable software in this directory, but it will only be available to users with permission to this directory. The home directory can be organized further with the use of sub-directories.

The content of a user's home directory is protected by file system permissions, and by default is accessible to all authenticated users and administrators. Any other user that has been granted administrator privileges has authority to access any protected location on the filesystem including other users home directories.

Home (Deep Blue Something album)

Home is the second album by alternative rock band Deep Blue Something. It was originally released by RainMaker Records in 1994 and re-released on Interscope in 1995.

Track listing

All songs written by Todd Pipes, except where noted.

B-Sides:

Charts

Personnel

Band Members

Home (Stephanie Mills album)

Home is a studio album by Stephanie Mills. It was released June 26, 1989 on MCA Records.

Track listing

Charts

References

External links