<< Chapter < Page Chapter >> Page >
A High-performance Window Source: http://www.energystar.gov/ia/new_homes/features/Windows_062906.pdf

Heating ventilation and air-conditioning (hvac)

A large part of the energy consumption and thus environmental impact of a building is the building heating, ventilation and air-conditioning (HVAC) systems that are used to provide comfortable temperature, humidity and air supply levels. Buildings must be designed to meet local energy code requirements, but these are often not as aggressive targets as they could be to demand more energy efficiency. In the U.S. ENERGY Star provides guidance and benchmarking to help set more aggressive goals.

There are many ways HVAC systems can be designed to be more efficient. Variable air volume (VAV) systems increase air flow to meet the increase or decrease in heat gains or losses within the area served. Having fans power down when not needed saves energy, as does reducing the amount of air that needs to be conditioned and also reduces the need for reheat systems. These systems are used to warm up an area if the cooled air supply is making an area too cold. VAV systems can generally handle this by reducing air supply. All of this does need to be balanced by making sure there is enough fresh air supply to meet the needs of the number of occupants in a building. Otherwise, it will feel stuffy due to lack of air flow and oxygen.

Also using automated controls, whether it is a programmable thermostat in your home or a building automation system (BAS) that uses computers to control HVAC settings based on schedules and occupancy, can significantly reduce energy consumption.

The equipment itself can be made more energy efficient. For instance new home furnaces range in efficiency from 68-97%. Ideally, the most energy efficient furnace would be installed in a new home ( U.S. Department of Energy, 2011 ).

Passive solar design

This type of architectural design does not require mechanical heating and cooling of a building. Instead it uses heating and cooling strategies that have been used historically such as natural ventilation, solar heat gain, solar shading and efficient insulation. Figure Passive Solar Design shows some of these elements. In the winter solar radiation is trapped by the greenhouse effect of south facing windows (north in the southern hemisphere) exposed to full sun. Heat is trapped, absorbed and stored by materials with high thermal mass    (usually bricks or concrete) inside the house. It is released at night when needed to warm up the building as it loses heat to the cooler outdoors. Shading provided by trees or shades keeps the sun out in the hot months.

Passive Solar Design Source: http://www.yourhome.gov.au/technical/fs45.html#what


Well-designed lighting can minimize the use of energy. This includes enhancing day lighting (natural light), through windows, skylights, etc. Using energy efficient lighting such as compact fluorescent light bulbs and LEDs (light-emitting diodes) can save energy as well. Using occupancy sensors also means that lights will only be on when someone is in a room. See Module Sustainable Energy Practices: Climate Action Planning for more energy-saving technologies that can be incorporated into buildings.

Questions & Answers

find the 15th term of the geometric sequince whose first is 18 and last term of 387
Jerwin Reply
I know this work
The given of f(x=x-2. then what is the value of this f(3) 5f(x+1)
virgelyn Reply
hmm well what is the answer
how do they get the third part x = (32)5/4
kinnecy Reply
can someone help me with some logarithmic and exponential equations.
Jeffrey Reply
sure. what is your question?
okay, so you have 6 raised to the power of 2. what is that part of your answer
I don't understand what the A with approx sign and the boxed x mean
it think it's written 20/(X-6)^2 so it's 20 divided by X-6 squared
I'm not sure why it wrote it the other way
I got X =-6
ok. so take the square root of both sides, now you have plus or minus the square root of 20= x-6
oops. ignore that.
so you not have an equal sign anywhere in the original equation?
is it a question of log
I rally confuse this number And equations too I need exactly help
But this is not salma it's Faiza live in lousvile Ky I garbage this so I am going collage with JCTC that the of the collage thank you my friends
Commplementary angles
Idrissa Reply
im all ears I need to learn
right! what he said ⤴⤴⤴
what is a good calculator for all algebra; would a Casio fx 260 work with all algebra equations? please name the cheapest, thanks.
Kevin Reply
a perfect square v²+2v+_
Dearan Reply
kkk nice
Abdirahman Reply
algebra 2 Inequalities:If equation 2 = 0 it is an open set?
Kim Reply
or infinite solutions?
The answer is neither. The function, 2 = 0 cannot exist. Hence, the function is undefined.
Embra Reply
if |A| not equal to 0 and order of A is n prove that adj (adj A = |A|
Nancy Reply
rolling four fair dice and getting an even number an all four dice
ramon Reply
Kristine 2*2*2=8
Bridget Reply
Differences Between Laspeyres and Paasche Indices
Emedobi Reply
No. 7x -4y is simplified from 4x + (3y + 3x) -7y
Mary Reply
how do you translate this in Algebraic Expressions
linda Reply
Need to simplify the expresin. 3/7 (x+y)-1/7 (x-1)=
Crystal Reply
. After 3 months on a diet, Lisa had lost 12% of her original weight. She lost 21 pounds. What was Lisa's original weight?
Chris Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
many many of nanotubes
what is the k.e before it land
what is the function of carbon nanotubes?
I'm interested in nanotube
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
preparation of nanomaterial
Victor Reply
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
good afternoon madam
what is system testing
what is the application of nanotechnology?
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
anybody can imagine what will be happen after 100 years from now in nano tech world
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
silver nanoparticles could handle the job?
not now but maybe in future only AgNP maybe any other nanomaterials
I'm interested in Nanotube
this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
can nanotechnology change the direction of the face of the world
Prasenjit Reply
At high concentrations (>0.01 M), the relation between absorptivity coefficient and absorbance is no longer linear. This is due to the electrostatic interactions between the quantum dots in close proximity. If the concentration of the solution is high, another effect that is seen is the scattering of light from the large number of quantum dots. This assumption only works at low concentrations of the analyte. Presence of stray light.
Ali Reply
the Beer law works very well for dilute solutions but fails for very high concentrations. why?
bamidele Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
Privacy Information Security Software Version 1.1a
Got questions? Join the online conversation and get instant answers!
QuizOver.com Reply
Practice Key Terms 5

Get the best Algebra and trigonometry course in your pocket!

Source:  OpenStax, Sustainability: a comprehensive foundation. OpenStax CNX. Nov 11, 2013 Download for free at http://legacy.cnx.org/content/col11325/1.43
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Sustainability: a comprehensive foundation' conversation and receive update notifications?