Monday, December 12, 2011

LEED

Leadership in Energy and Environmental Design
  • LEED is a green building certification. 
  • Innovative ways to construct or  renovate buildings 
  • Reduce the carbon footprint left behind 
  • Provides guidelines and standards throughout the design, construction, operations and maintenance  phases.
Why LEED?
  • Reduced carbon footprint
  • Lower operating costs
  • Conserve energy and water
  • Improves the overall performance and quality of a building
How it Works?
LEED operates on a points rating system for a building split up into 5 main categories.

Sustainable Sites
  • Site selection and development. 
  • Points are awarded for: 
  • Preserving the land and its surrounding ecosystems 
  • Reducing local heat effects to erosion

Water Efficiency
  • Encourages a reduction in the use of water. 
  • Outside:- Irrigation and rain harvesting systems. 
  • Inside:- High efficiency appliances and fittings.

Energy & Atmosphere
  • Most important section, and is weighted appropriately. 
  • It is most important because it focuses on reducing energy consumption. 
  • This can be achieved in a great number of ways, all aimed at reducing the overall energy consumption of the building, thus reducing its carbon footprint.

Materials & Resources
  • Reducing waste. 
  • This applies primarily to the construction and operation 
  • Dependent on the materials used for everything from framing to flooring.
  • Economically preferable products 
    • Recycled 
    • Low emissions 
    • Extracted, processed and manufactured within 500 miles.

Indoor Environmental Quality
  • Improve living conditions within the house
  • Smaller impact on the outside world around it
  • This includes better air quality indoors through the use of 
    • Moisture control 
    • Ventilation 
    • Air Filtering
Bonus Points are also available from:
Innovation in Design
Locations and Linkages
Awareness & Education

ENERGY STAR

LEED strongly encourages the use of ENERGY STAR rated products in the home. This can range from lighting to high efficiency appliances.

In 2010 Americans who used ENERGY STAR products helped saved enough energy to avoid greenhouse gas emissions equivalent to 33 million cars in 2010 while also saving $18 billion on utility bills.

Gold Certification Results

Costs and Impact of a LEED Home






Sunday, December 11, 2011

System Design

Maximum qsupply is in December: 11,000 Btu/hour
COP = 4.3
Max pump work = 2,600 Btu/hour

Tout = 38.5 degrees F
Tin = 42 degrees F

UA-pipe = 891
Rs = .7226/Length
Rp = .1571/Length
Rw = .01533/Length

Pipe Length = 800 Feet


Payback Time:
Capital Cost = $3,080
Fuel difference = $220/year

Simple Payback Time = 14.5 years

Feasibility

Three possible designs: Wind Power, Solar Power, Geothermal

Wind Map over Boulder, Colorado:

Solar Radiation Map over Boulder, Colorado:


Geothermal:
Ground temperature = 50 degrees F

Sunday, October 30, 2011

Home energy

For a 1000 square foot home with 8 foot ceiling, we assumed the wall was made of bevel wood siding, polywood sheething, 3 1/2" fiberglass batt, 3 1/2" wood studs, 1/2" drywall, and 15% stud contribution to 85% cavity contribution. We also assumed that there were 14  air exchanges per hour. Using these assumptions, the values we got for a home in Boulder, CO are:

Rsiding=.8;
Routerins=.63;
Rinnerins=13;
Rstud=4.38;
Rdrywall=.45;
Riair=.68;
Roair=.17;
Rshingles=.44;
Rattic=3.1

Rwall = 13.3
Rceiling = 16.8
UA = 2.78
ma = 1498 lb/hr
cpa = 0.24 BTU/(lb °F)

JAN
FEB
MAR
APR
MAY
JUN
34.54
35.87
42.51
48.63
57.59
65.98
JUL
AUG
SEP
OCT
NOV
DEC
73.54
70.89
62.88
51.34
41.78
34.08

Heating degree days:5320
Cooling degreedays:476

Qh = 1,927,000 BTU/year
Qc = 172,700 BTU/year