digplanet beta 1: Athena
Share digplanet:

Agriculture

Applied sciences

Arts

Belief

Business

Chronology

Culture

Education

Environment

Geography

Health

History

Humanities

Language

Law

Life

Mathematics

Nature

People

Politics

Science

Society

Technology

A building envelope is the physical separators between the conditioned and unconditioned environment of a building including the resistance to air, water, heat,[1] light, and noise[2] transfer. The three basic elements of a building envelope are a weather barrier, air barrier, and thermal barrier.[3] The weather barrier may be in a different location than the air and thermal barriers such as in house with an unheated attic. The term building envelope is sometimes used synonymously with building enclosure but the latter term also includes the broader aspects of appearance, structure, safety from fire[4] and security. The act of creating a building envelope is sometimes called weatherization.

Discussion[edit]

The building envelope is all of the elements of the outer shell that maintain a dry, heated, or cooled indoor environment and facilitate its climate control. Building envelope design is a specialized area of architectural and engineering practice that draws from all areas of building science and indoor climate control.[2]

The many functions of the building envelope can be separated into three categories:[5]

  • Support (to resist and transfer mechanical loads)
  • Control (the flow of matter and energy of all types)
  • Finish (to meet human desires on the inside and outside)

The control function is at the core of good performance, and in practice focuses, in order of importance, on rain control, air control, heat control, and vapor control.[5]

Water and water vapor control[edit]

Control of rain is most fundamental, and there are numerous strategies to this end, namely, perfect barriers, drained screens, and mass / storage systems.[6] Damp proofing and

One of the main purposes of a roof is to resist water. Two broad categories of roofs are flat and pitched. Flat roofs actually slope up to 10° or 15° but are built to resist standing water. Pitched roofs are designed to shed water but not resist standing water which can occur during wind-driven rain or ice damming. Typically residential, pitched roofs are covered with an underlayment material beneath the roof covering material as a second line of defense. Domestic roof construction may also be ventilated to help remove moisture from leakage and condensation.

Walls do not get as severe water exposure as roofs but still leak water. Types of wall systems with regard to water penetration are barrier, drainage and surface-sealed walls.[7] Barrier walls are designed to allow water to be absorbed but not penetrate the wall, and include concrete and some masonry walls. Drainage walls allow water that leaks into the wall to drain out such as cavity walls. Drainage walls may also be ventilated to aid drying such as rainscreen and pressure equalization wall systems. Sealed-surface walls do not allow any water penetration at the exterior surface of the siding material. Generally most materials will not remain sealed over the long term and this system is very limited, but ordinary residential construction often treats walls as sealed-surface systems relying on the siding and an underlayment layer sometimes called housewrap.

Moisture can enter basements through the walls or floor. Basement waterproofing and drainage keep the walls dry and a moisture barrier is needed under the floor.

Air control[edit]

Main article: Air barrier

Control of air flow is important to ensure indoor air quality, control energy consumption, avoid condensation (and thus help ensure durability), and to provide comfort. Control of air movement includes flow through the enclosure (the assembly of materials that perform this function is termed the air barrier system) or through components of the building envelope (interstitial) itself, as well as into and out of the interior space, (which can affect building insulation performance greatly). Hence, air control includes the control of windwashing[8] (cold air passing through insulation) and convective loops which are air movements within a wall or ceiling that may result in 10% to 20% of the heat loss alone.[9]

The physical components of the envelope include the foundation, roof, walls, doors, windows, ceiling, and their related barriers and insulation. The dimensions, performance and compatibility of materials, fabrication process and details, connections and interactions are the main factors that determine the effectiveness and durability of the building enclosure system.

Common measures of the effectiveness of a building envelope include physical protection from weather and climate (comfort), indoor air quality (hygiene and public health), durability and energy efficiency. In order to achieve these objectives, all building enclosure systems must include a solid structure, a drainage plane, an air barrier, a thermal barrier, and may include a vapor barrier. Moisture control (e.g. damp proofing) is essential in all climates, but cold climates and hot-humid climates are especially demanding.[10]

Thermal envelope[edit]

The thermal envelope, or heat flow control layer, is part of a building envelope but may be in a different location such as in a ceiling. The difference can be illustrated by understanding that an insulated attic floor is the primary thermal control layer between the inside of the house and the exterior while the entire roof (from the surface of the shingles to the interior paint finish on the ceiling) comprises the building envelope.[11]

Building envelope thermography involves using an infrared camera to view temperature anomalies on the interior and exterior surfaces of the structure. Analysis of infrared images can be useful in identifying moisture issues from water intrusion, or interstitial condensation.[12]

See also[edit]

References[edit]

  1. ^ Cleveland, Cutler J., and Christopher G. Morris. "Building envelope (HVAC)". Dictionary of Energy. Expanded Edition. Burlington: Elsevier, 2009. Print.
  2. ^ a b Syed, Asif. Advanced building technologies for sustainability. Hoboken, N.J.: John Wiley & Sons, Inc., 2012. 115. Print.
  3. ^ Wilson, Jeff. The Greened House Effect: Renovating Your Home with a Deep Energy Retrofit. Chelsea Green Publishing, White River Junction. 2013. 42. print.
  4. ^ Wong, Wah. Building enclosure in Hong Kong. Hong Kong: Hong Kong University Press, 1998. 1. Print.
  5. ^ a b Straube, J.F., Burnett, E.F.P. Building Science for Building Enclosures. Building Science Press, Westford, 2005.
  6. ^ 11. Straube, J.F. and Burnett, E.F.P., "Rain Control and Design Strategies". Journal Of Thermal Insulation and Building Envelopes, July 1999, pp. 41-56.
  7. ^ various authors. Guideline for condition assessment of the building envelope. Reston, Va.: American Society of Civil Engineers, 2000. 4. Print.
  8. ^ Hens, Hugo S. L. C. Performance Based Building Design 2: From Timber-framed Construction to Partition Walls. Berlin: Ernst, William & Son, 2012. 10. Print.
  9. ^ Harrje, D. T, G. S. Dutt and K. J. Gadsby, "Convective Loop Heat Losses in Buildings". Oak Ridge National Laboratory. 1985. Print.
  10. ^ Lstiburek, Joseph W., and John Carmody. Moisture Control Handbook: Principles and Practices for Residential and Small Commercial Buildings. New York: Van Nostrand Reinhold, 1993. 88. Print.
  11. ^ Vliet, Willem. The Encyclopedia of Housing. Thousand Oaks, Calif.: Sage, 1998. 139. Print.
  12. ^ Hunaidi, Osama. Leak Detection Methods for Plastic Water Distribution Pipes. Denver, Colo.: AWWA Research Foundation, 1999. 57. Print.

External links[edit]


Original courtesy of Wikipedia: http://en.wikipedia.org/wiki/Building_envelope — Please support Wikipedia.
This page uses Creative Commons Licensed content from Wikipedia. A portion of the proceeds from advertising on Digplanet goes to supporting Wikipedia.
1 videos found

https://youtube.com/devicesupport

https://youtube.com/devicesupport http://m.youtube.com

 
1 videos found

6759 news items

 
Wicked Local Topsfield
Fri, 22 May 2015 11:45:00 -0700

The once beautiful façade of the Topsfield Town Hall is marred by plywood, plastic and duct tape, but the future is looking brighter since the Town Meeting voters approved funds to stabilize the building envelope and allotted an additional $100,000 to ...
 
ACHR NEWS
Fri, 22 May 2015 04:43:07 -0700

BIPV takes on the dual role of both building envelope material and power generator, thus providing significant savings in terms of electricity and materials costs. Driven by technological advancements, BIPV systems are being designed to completely ...
 
USGlass Metal & Glazing
Wed, 13 May 2015 20:33:45 -0700

Have you seen the new acronym “BECx” – building envelope commissioning? No, it has nothing to do with GANA's BEC. I'm still trying to get straight in my head why this is needed. After talking to a former colleague, it seems like this is NFRC all over ...
 
Hartford City News Times
Thu, 21 May 2015 15:18:45 -0700

Brown said that potential projects for energy saving in the schools would include working on "control system upgrades, lighting system upgrades, boilers, VAV conversions, pool efficiency, the building envelope and water conservation." Zellman said that ...
 
The Daily Courier
Fri, 22 May 2015 06:07:30 -0700

There are a number of software programs that attempt to model the amount of energy lost through a building's envelope, because that is the amount of energy you're heating and cooling system has to replace to keep a constant internal temperature. The ...
 
Stockhouse
Fri, 22 May 2015 13:26:15 -0700

... complete turnkey LED lighting retrofits (including financing), supply of conventional and "green" electricity for homes and businesses, commercial solar PV installations, home protection plans, building envelope upgrades, energy audits and more to ...

Courier-Gazette & Camden Herald

Courier-Gazette & Camden Herald
Fri, 22 May 2015 16:02:22 -0700

2008, that shows the new building envelope that is 10 feet at its widest point. At the bottom is a portion of the permit application from 2009 where the lot has mysteriously tripled in size. Below that is a part of the application that any citizen ...
 
Consulting-Specifying Engineer
Thu, 21 May 2015 23:00:00 -0700

Power. Fire, Life Safety. Electrical, Lighting. Building Types. Codes and Standards. HVAC. Education and Training. 40 Under 40 · Building Envelope · Case Study Database · Commissioning · Integration · MEP Giants · Projects in Progress · Product of the ...
Loading

Oops, we seem to be having trouble contacting Twitter

Support Wikipedia

A portion of the proceeds from advertising on Digplanet goes to supporting Wikipedia. Please add your support for Wikipedia!

Searchlight Group

Digplanet also receives support from Searchlight Group. Visit Searchlight