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Passive design

Passive design is the design that takes advantage of the climate to maintain a

comfortable indoor climate in the home. Passive design reduces or eliminates the need

for auxiliary heating or cooling

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Passive design issues • Major principles

• Passive heating

• Passive cooling

• Hybrid system

• Day lighting

• Renewable in building

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Passive design means

No auxiliary equipment are required to make the system to function

Factors

• Orientation

• Fenestration and shading

• Envelop

• Day lighting

• Thermal mass

• Renewable adaptation

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Six major principles 1. Orientation

2. Glazing

3. Thermal mass

4. Insulation

5. Ventilation

6. Zoning

Passive cooling

1) Reducing cooling load

2) Using passive techniques

3) Improving efficiency of cooling equipment and thermal distribution systems.

Reducing cooling loads

• Orientation of building

• Clustering buildings to provide self shading

• High-reflectivity building materials

• Increasing insulation

• Glazing on windows with a low solar heat gain and a high daylight transmission

• Avoiding excessive window area

• Utilizing thermal mass

Housing materials

Materials Overall heat transfer co-

efficient ,U W/m2K

Outer wall (solid brick, cement sand

Plaster and Insulation )

2.22

Internal wall (brick and cement sand

plaster

2.22

Floor (ground ) Solid concrete 0.80

Floors (intermediate ) Solid concrete and

plaster board

1.7

Roof (pitched with felt ) 0.6

Window ( wooden frame and single glazed 2.9

Door ( solid timber door) 1.7

Comparatively higher U values

Passive technique

Natural ventilation

Evaporative cooling

Other passive cooling techniques

Passive cooling

Solar shading

Providing thermal mass

Stack ventilation by duct or chimney

Wind driven ventilation

Passive lighting

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Zero-energy building

• A zero-energy building (nZEB), also known as a zero net energy (ZNE)

building, is a buildings use with zero net energy consumption and zero carbon

emissions annually.

• Zero-energy buildings use energy from

• grid supply

• on-site usually in combination with energy producing technologies such

as solar and wind

• reducing the overall use of energy with efficient HVAC and lighting

technologies

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Other names near-zero energy building

ultra-low energy house

energy-plus buildings

The benefits of a ZEB usually are as follows:

• Isolation for building owners from future energy price increases

• Reduced requirement for energy austerity

• Reduced total cost of ownership due to improved energy efficiency

• Reduced total net monthly cost of living

• Improved reliability: extra cost is minimized for new construction compared to an afterthought Retrofit

• Higher resale value as potential owners demand more ZEBs than available supply

• Future legislative restrictions, and carbon emission taxes/penalties

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Zero-energy dwellings

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Zero-energy building characteristics

• Advanced HVAC and lighting controls

• Smart metering capabilities, allowing

central access to real-time utility data

• A structured cabling infrastructure with

high bandwidth and connectivity

• Adaptability to changing technology and

tenant needs

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Zero-energy house using PV system

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Some smart solutions to make a zero-energy building

1. Decrease the energy requirements for space heating, cooling, and water

heating:

• Orient the home with smaller walls facing west and include overhangs and

porches

• Increase foundation, wall, and ceiling insulation

• Use low U-value, low-E windows in all climates and low solar heat gain (low

SHGC) windows in cooling climates

• Seal all holes, cracks, and penetrations through the floor, walls, and ceiling to

unconditioned spaces

• Install adequate ventilation, especially from kitchens and baths

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2. Increase the efficiency of the furnace (or heat pump), and the air-

conditioner:

• Buy as high-efficiency equipment as affordable for the climate

• Design the supply and return duct system appropriately and seal tightly

using approved tapes or mastic

• Where climate-appropriate consider alternative cooling systems such as

ventilation only or evaporative coolers

• Heat pump

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3. Install a solar hot water preheat system, an efficient backup water heater, and

an efficient distribution system:

• Consider a parallel, small diameter piping system for the hot water outlets

• Install low-flow fixtures

• Choose water heating equipment with a high energy factor

• Evaluate solar systems

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4. Install efficient lighting fixtures:

• Consider permanent fluorescent fixtures in as many locations as

possible

• Look for the ENERGY STAR compliance

5. Install efficient appliances:

• Include the refrigerator, dishwasher, and laundry appliances

• Look for the ENERGY STAR compliance

• Compare appliance efficiencies

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6. Install a properly sized photovoltaic system

7. Turn off lights, computers, and appliances when not in use

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1. The concept-passive design

2. What do you understand by zero-energy building?

3. Give some simple solutions to make a zero-energy building?

4. Give some advantages and disadvantages of a nZEB?

5. How could encourage the homeowners to get a zero-energy house?

6. What are the characteristics of a zero-energy building?

Discuss with peer give your

opinion