energy & atmosphere. 1.sustainable sites 2.water efficiency 3.energy & atmosphere goals...

Energy & Atmosphere

1. Sustainable Sites2. Water Efficiency3. Energy & Atmosphere

• Goals & Background• Climate Assessment• Building Massing & Orientation• The Building Envelope• Energy Systems• Renewable Energy• LEED NC Prerequisites & Credits

• Intents & Strategies• LEED O&M Prerequisites & Credits

• Intents & Strategies

Session 2: Agenda

What are the goals of Energy & Atmosphere Section?

Energy & Atmosphere: Goals & Background

• Reduce energy consumption• Increase on-site renewable energy generation• Increase market for off-site renewable energy

generation• Reduce ozone layer depletion and global warming

gas generation

The impact of architects and engineers:

The building, industry and transportation sectors are the three sectors that consume energy in the US. Buildings are the largest consumers of energy.


What architects and engineers influence:A reorganization of the data shows that when the energy required to run buildings is combined with the embodied energy of industry-produced materials such as carpet, tile and hardware, architects and engineers are exposed as the hidden polluters.


Energy & Atmosphere: Climate Assessment

MA = 5A

Climate Zones (ASHRAE 90.1):


Temperature

Also:• Precipitation Wind Speed

Insolation

Thermal Comfort

Natural Ventilation Potential

Relative Humidity

Temp. Insolation

Average day for each month

Jan 1st (1 day)


Micro-Climate:

• Topography• Soil Types• Vegetation• Bodies of Water• Built Environment & Hardscape

The factors above can all effect temperature,humidity, wind speed, solar heat gain, etc.


Climate Specific Design:

Hot-Dry:• High thermal mass, small

windows, flat roofs, night ventilation

Hot-Moist:• Low thermal mass, natural

ventilation, roof overhangs


Climate Specific Design:

Cold:• Highly insulated, south-facing

windows, high volume, low surface area

Temperate:• Well insulated, shade windows in

summer, un-shaded in winter

Strategic massing & orientation reduces energy consumption & allows for increased connection to the natural environment.

Energy & Atmosphere: Building Massing & Orientation

• Linear E-W geometry allows for reduced solar heat gain and glare, and increases opportunities for daylighting.

Soka Bau, Herzog Wessex Water Operation Center, Bennett Architects

Energy & Atmosphere: Building Massing & Orientation

Increased access to natural ventilation and views must be balanced with the fact that very thin floor-plates have an increased surface to volume ratio, increasing heating and cooling loads.

Energy & Atmosphere: Building Envelope

The building envelope:


The building envelope must mitigate many factors, including:

• Precipitation (rain/snow)• Ground Water• Airflow *• Thermal Resistance *• Water Vapor• Solar Heat Gain *• Visible Light *• Views / Access

* These factors directly impact building energy consumption.


What are the elements of the building envelope and what strategies optimize energy performance?

• Airflow• Thermal Resistance• Solar Heat Gain• Visible Light

• Roofs• Walls• Fenestration• Foundations


Unintended airflow (air infiltration) can quickly transfer heat in or out of the building.Air also carries dust and moisture, potentially leading to poor indoor air quality and mold growth. Therefore, the envelope is sealed as tight as possible.




To stop air flow, materials and assemblies create a barrier to air movement, called an “air barrier”.



• The air barrier must be a continuous system, accounting for all surfaces and joints.




Window Air Leakage (AL) is indicated by an air leakage rating expressed as the equivalent cubic feet of air passing through a square foot of window area (cfm/sq ft).

Blower-Door

Smoke Pen


Testing for air leakage is critical.(otherwise leaks can’t readily be seen)

Theatrical Fog




When carefully planned and controlled, air flow can be used to save energy and increase comfort.



• Passive ventilation can reduce the time when mechanical systems must provide fresh air and cooling.

solar chimneys(hot-dry climate)


Thermal resistance (R-value) is a measure of how well a material resists heat transfer through conduction.



• U-value is the inverse of R-value. It measures a material’s ability to transfer heat through conduction.




R=1/U




Thermal bridges:




Infrared Test:




Insulation:

Board FoamSpray-Foam Mineral WoolCellulose

http://www.buildinggreen.com/auth/image.cfm?imageName=images/1808/Mineral-wool.jpg&fileName=180801a.xml

http://www.buildinggreen.com/auth/image.cfm?imageName=images/1808/ext-foam.jpg&fileName=180801a.xml




Windows are typically the building system with the lowest insulating value.




Windows are also the building system with the highest solar heat gain.

• Solar Heat Gain Coefficient (SHGC) measures the percent of solar radiation that passes through the window.




Too much unshaded glazing leads to large cooling loads.

• Minimizing the SHG and providing exterior shading saves energy.

http://images.google.com/imgres?imgurl=http://upload.wikimedia.org/wikipedia/commons/d/d5/Glass_building_in_Chicago.jpg&imgrefurl=http://commons.wikimedia.org/wiki/File:Glass_building_in_Chicago.jpg&usg=__P06ab-fZLC9bFNbWcTe7esak1YE=&h=1920&w=2560&sz=1373&hl=en&start=2&sig2=UauhKnK8lIbRHqpPOMH8sA&um=1&tbnid=iknWXof54Ug7pM:&tbnh=113&tbnw=150&prev=/images?q=glass+building&hl=en&rls=com.microsoft:en-us&um=1&ei=QNTUSs3jJYvQNPDmmZQD




Similar to airflow, .When carefully planned and controlled, solar heat gain can be used to save energy.

• Passive solar heating can reduce energy consumption in winter.


• Light colored roofs help to reduce heat gain from the sun and reduce the temperature where mechanical cooling systems are often located.

• Roof overhangs can also shade windows below.



Roofs can also absorb heat from the sun.


• Increasing the VLT, while decreasing the SHGC may reduce energy consumption by

offsetting the need for electrical lighting without increased cooling loads.



Visible Light Transmittance (VLT) is the percent of visible light that passes through the window.




To achieve substantial energy savings, the NY Times building optimized the balance between:

• Exterior shading• Window performance• Advanced lighting controls• Automatic interior shades

Energy & Atmosphere: Energy Systems

Energy Systems:


Energy Flow: Primary Fuel Sources

By rotating turbines (direct kinetic energy)

By burning biodegradable waste and rotating turbines By rotating turbines from heat energy (“deep earth”)

By rotating turbines (direct kinetic energy)By converting solar energy to electrical energy (Photovoltaic)By rotating turbines

By “fission reaction” and generating heat to rotate turbines

By burning natural gas and use heat energy to rotate turbines

By burning petroleum and use heat energy to rotate turbines


Energy Flow: Primary Fuel Sources


How is this energy used in buildings?

Mechanic Mechanical Systems

Heating (Air, Domestic Water)Cooling (Air, Chilled Water)Dehumidification (Air)Ventilating (“Breathable air”)

Electrical Systems

Lighting & Daylighting SensorsPlug Loads (Computers, Appliances, etc)Process Loads (Elevators, Refrigeration / Cooking, etc)HVAC Equipment (Motors, Fans, etc)


Mechanical Systems

Heating:- Typically on-site combustion of fuel

or electrical resistance to heat air or water which is used to distribute heat to the space

- Also relates to heating domestic hot water (typically used in showers and sinks)

Standard: ASHRAE 55 (thermal comfort)


Mechanical Systems

Cooling:- Using refrigerant to “pump” heat from inside to the outdoors (A/C).(‘Heat-Pump’ can reverse it’s cycle to pump heat from the outdoors to inside).

Terms: compressor, condenser, heat exchanger, evaporator, cooling coilStandard: ASHRAE 55

(thermal comfort)


Mechanical Systems

Dehumidification:- Used for removing moisture in air for providing comfort.- The cooling coil in the air handling unit typically achieves 2 things:(1) Condensation forms on the cold

surface of the coil, dehumidifying the air.

(2) Air is cooled to required temperature.

Relative Humidity (RH), unit is %


Mechanical SystemsVentilation:- Ventilation is “fresh / breathable air.”- Allow fresh air from outside constantly.- If outside temperature is not comfortable,

either heat or cool the air before it is sent to the space.

- If outside temperature is comfortable, use it to “condition” the space (free!).

Minimum ventilation (fresh air) is required for human occupancy.Ventilation is measured in “Cubic Feet Per Minute” or CFM (I.P. Units).Standard: ASHRAE 62.1 (ventilation)


Electrical SystemsLighting:- Electrical lighting systems consume

energy. - These systems also generate heat that

flows into the space and also inside the ceiling plenum.

- Lighting systems are designed for adequate illuminance (light that falls on the table). Quality of this light is important for color rendering.

Lighting Power Density (LPD) is amount of lighting energy (watts) per SF (I.P. Unit).Standard: ASHRAE / IESNA 90.1


Electrical Systems

Daylighting Sensors:- Daylighting sensors “sense” amount

of lighting and allows switching on / off of electrical lighting.

- Energy savings potential!- Daylighting sensors are low energy

systems (use very little electrical energy).

Illuminance is measured in foot candles.


Electrical Systems

Plug Loads:- Electrical energy consumed by

computers, table lamps, TVs, etc.- Also referred to as “receptacle loads.”- Plug loads generate heat too!- It is important to provide only optimum

number of receptacles (what is required).

Equipment Power Density (EPD) is amount of electrical energy (Watts) per SF (I.P. Unit).


Electrical Systems

Process Loads:- Electrical energy consumed by

vertical transportation systems (elevator, escalators), cooking, refrigeration, etc.

- Process loads are typically 25% of total energy requirement of a building.

- Process loads generate heat too!

Energy & Atmosphere: Electrical Systems

Electrical Systems

HVAC Equipment Loads:- HVAC equipment (motors, fans,

compressor, etc) consume electrical energy.

- These loads generate heat too!

Mechanical SystemsHeatingCoolingDehumidificationVentilating

Electrical SystemsLighting & Daylighting SensorsPlug Loads (Computers, Fans, etc)Process Loads (Elevators, Refrigeration)HVAC Equipment (Motors, Fans, etc)


How do you ensure that these systems are installed and working as designed?

Building Commissioning

(Fundamental & Enhanced)

AND

Measurement & Verification (M&V)

Solar Resource

Energy & Atmosphere: Renewable Energy


Solar Energy

- Used to generate electricity (using photovoltaics).

- Used to generate heat energy (solar thermal energy for heating water).

Wind Resource



Wind Energy

- Used to generate electricity (using blades that rotate turbines).

- Generation is proportional to the cube of the wind speed.

energy & atmosphere. 1.sustainable sites 2.water efficiency 3.energy & atmosphere goals...

Documents

embodied energy of industry

largest consumers of

climate data

ashrae climate zones

climate assessmentma

climate analysis

climate consultant

day yellow