Energy Efficiency and Window to Wall Ratio

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the effect of a Window to Wall Ratio (WWR) less than 30% on energy efficiency?

It reduces energy consumption and improves material usage. (correct)

It has no significant effect on energy performance.

It maximizes cooling load in warmer climates.

It increases heat gain significantly.

Why is glass considered the weakest link in the building envelope?

It does not allow any natural light into the building.

It is more expensive than other materials.

It has a higher resistance to heat flow.

It transmits heat into the building at a higher rate than walls. (correct)

What should the design goal be when considering Window to Wall Ratio (WWR)?

To meet minimum illumination without exceeding solar heat gains. (correct)

To have equal amounts of glass and solid walls.

To maximize costs of glazing.

To reduce the number of windows in all climates.

In what climate conditions are glazed areas beneficial?

In cold climates during the day. Signup and view all the answers

What ratio defines the Window to Wall Ratio (WWR)?

The total area of windows divided by the gross exterior wall area. Signup and view all the answers

What is the primary drawback of having a high Window to Wall Ratio (WWR) in warm climates?

It significantly increases the building’s cooling loads. Signup and view all the answers

What contributes to the effective management of energy efficiency in building designs?

Balancing glazing benefits with heat gain impacts. Signup and view all the answers

What aspect of glazing affects energy performance the most?

The surface area of the glazing compared to the walls. Signup and view all the answers

What is the primary benefit of using Variable Speed Drive (VSD) motors in cooling systems?

They reduce energy consumption and utility costs. Signup and view all the answers

Which of the following systems can use Variable Speed Drives (VSDs)?

Air-cooled chillers Signup and view all the answers

What efficiency level does the Base Case assume for a gas-fired hot water boiler?

78% Signup and view all the answers

What is the purpose of a fresh air pre-conditioning system in a ventilation setup?

To reduce temperature difference and lower load on conditioning systems. Signup and view all the answers

Which of the following is NOT a benefit mentioned for using Variable Speed Drives?

Increased wear and tear on components. Signup and view all the answers

Under what condition can energy savings from Variable Speed Drives be claimed?

If the air conditioning system selected can use VSDs. Signup and view all the answers

What type of energy source is predominantly used for space heating in buildings?

Fossil fuels Signup and view all the answers

Which statement is true regarding pre-conditioning of fresh air?

It helps in reducing the cooling and heating loads on a building. Signup and view all the answers

What is the primary function of EDGE regarding external walls?

To save embodied energy by reducing material quantity or finding alternatives Signup and view all the answers

What does the EE value indicate in the context of insulation measures?

The embodied energy of the materials per square meter Signup and view all the answers

In the context of window frames, how are their energy values calculated?

Using the Window to Wall Ratio (WWR) indicated in the Energy tab Signup and view all the answers

What is the embodied energy value for the common used material in exterior walls?

1616 MJ/m2 Signup and view all the answers

Which of the following options represents an action to reduce embodied energy for external walls?

Reducing material quantity or finding alternatives Signup and view all the answers

What is the requirement for a second predominant material to be indicated in a project?

It must cover more than 25% of the area. Signup and view all the answers

What does EDGE provide to ensure fair comparison of materials?

Default embodied energy values. Signup and view all the answers

How should additional materials beyond the first two be represented?

By one of the two selected materials that is nearest in embodied energy. Signup and view all the answers

What methodology does EDGE use for evaluating embodied energy values?

EDGE Emerging Economies Construction Dataset. Signup and view all the answers

Which material is considered the most 'green' according to the ranking provided?

Concrete blocks Signup and view all the answers

What characteristic does the EDGE Materials Reference Guide detail about default materials?

Minimum and maximum thickness considerations. Signup and view all the answers

Why doesn't EDGE allow the addition of custom materials?

To ensure consistency in evaluations. Signup and view all the answers

What is one feature of the EDGE Materials Reference Guide?

It contains a complete list of materials available in the EDGE App. Signup and view all the answers

What is the purpose of a higher solar reflectance index (SRI) for roofs and walls?

To reduce cooling loads and improve thermal comfort Signup and view all the answers

How does the solar reflectance index (SRI) of a surface relate to environmental heat management?

A higher SRI can help reduce the urban heat island effect Signup and view all the answers

What is the main advantage of external shading devices compared to internal shading devices?

They are more effective at blocking radiant solar heat gain Signup and view all the answers

What characteristic of SRI makes it different from visible solar reflectance?

SRI includes thermal emittance properties Signup and view all the answers

What effect does reducing the surface temperature of reflective finishes have?

Extending the service life of the finish Signup and view all the answers

How is the effectiveness of external shading devices modeled in EDGE?

By projecting sun rays to a horizontal or vertical plane next to the window Signup and view all the answers

What do SRI values above 100 indicate?

The surface is more reflective than a standard white surface Signup and view all the answers

What phenomenon traps radiant solar gain inside a room?

The greenhouse effect Signup and view all the answers

What is the main intent of EEM33 – Onsite Renewable Energy?

To displace fossil-fuel-based energy with renewable sources. Signup and view all the answers

What criteria must be met to claim savings under EEM33?

The renewable energy source must be located onsite. Signup and view all the answers

What does EEM34 – Additional Energy Saving Measures allow for?

Filing a request for energy savings not listed in EDGE measures. Signup and view all the answers

What is a requirement for claiming EEM35 – Offsite Renewable Energy Procurement?

A contract for off-site renewable energy must be signed. Signup and view all the answers

How does offsite renewable energy procurement impact operational CO2 savings?

It has no effect on operational CO2 savings. Signup and view all the answers

What is essential for a project to achieve EDGE Zero Carbon certification under EEM35?

Achieving at least 40% savings in energy consumption. Signup and view all the answers

What benefit does investing in offsite renewable energy provide for dense urban projects?

It helps create new clean energy resources on the grid. Signup and view all the answers

What type of energy does offsite renewable energy not include?

Fossil fuel energy. Signup and view all the answers

Study Notes

Module 5 - EDGE V3 Technical Online Workshop

The module covers energy efficiency, water efficiency, and materials efficiency measures.
Energy Efficiency Measures are divided into two parts: Part 1 (EEM1 - EEM17) and Part 2 (EEM18 - EEM37).
Water Efficiency Measures cover various water-efficient fixtures and appliances.
Materials Efficiency Measures cover floor slabs, roof construction, external walls, internal walls, flooring, window frames, roof insulation, and wall insulation.

Energy Efficiency Measures - Part 1 (EEM1 - EEM17)

EEM01 (Window-to-Wall Ratio): Balancing glazing's lighting and ventilation benefits with heat gain impacts is crucial for cooling needs/passive heating. Optimizing the transparent (glass) and opaque surfaces minimizes unwanted heat transfer and maximizes daylight.
The goal is to achieve minimum illumination levels without exceeding solar heat gains in warmer climates and maximize passive heating in colder climates.
Buildings with less than 30% Window-to-Wall Ratio (WWR) generally shows better energy efficiency and material usage.
WWR is calculated as the sum of glazing area divided by the gross exterior wall area.

Materials Efficiency Measures

This section focuses on embodied energy of the materials used in the building.
Materials that are considered include floor slabs, roof construction, exterior walls, interior walls, flooring, window frames, roof insulation, and wall insulation.
The module provides options for selecting and applying various materials and insulation measures for different building types.

Water Efficiency Measures

Measures to improve water efficiency are included, focusing on different fixtures and appliances.
Included measures cover showerheads, faucets, water closets (toilets), bidets, kitchen sinks, dishwashers, washing machines, swimming pool covers, landscape irrigation systems, rainwater harvesting, and water treatment/recycling systems.

Other Measures

EEM02 (Reflective Roof): Reduced cooling loads in air-conditioned spaces and improved thermal comfort via increased roof reflectance index (SRI).
EEM03 (Reflective Exterior Walls): Similar to EEM02, improving SRI of external walls reduces cooling demand.
EEM04 (External Shading Devices): External shading devices reduce direct solar radiation, reducing glare and radiant solar heat gain, particularly beneficial in warmer climates.
EEM05 (Roof Insulation): Details on insulation types and their impact on thermal conductivity.
EEM06 (Ground/Raised Floor Slab Insulation): Covers thermal insulation measures for ground and raised floors.
EEM07 (Green Roof): Explores the energy efficiency gain from vegetation on flat roof areas, reducing heat transfer and improving stormwater retention.
EEM08 (External Wall Insulation): Details on insulation measures for external walls.
EEM09 (Efficient Glass): Claiming this measure involves using low-E coated glass, which reflects thermal energy.
EEM10 (Air Infiltration of Envelope): Reducing air infiltration reduces workload on AC. Measured in air changes per hour (ACH) or volume per time per unit surface area (Liters/s-m2).
EEM11 (Natural Ventilation): Utilizing pressure differences between openings to ventilate interior spaces, reducing energy needed from air-conditioning.
EEM12 (Ceiling Fans): Improving occupant comfort by increasing air movement, often considered as an auxiliary measure.
EEM13 (Cooling System Efficiency): This describes how the Coefficient of Performance (COP) of an existing cooling system can be used to identify savings compared to a baseline case. The baseline case will be the typical heating ventilation air conditioning (HVAC) system.
EEM14 (Variable Speed Drives): This discusses the energy-saving benefits of using variable speed drives (VSD) on fans, motors, and pumps in HVAC systems, which improve system reliability and process control.
EEM15 (Fresh Air Pre-conditioning System): Preconditioning the fresh air entering the ventilation system to reduce the temperature difference between inside and outside air, improving the efficiency of the space conditioning system.
EEM16 (Space Heating System Efficiency): Installing an efficient space heating system with a efficiency better than the standard baseline. This measure has specific requirements based on the heating fuel type, to comply with energy saving measures.
EEM17 (Room Heating Controls with Thermostatic Valves): Using thermostatic valves to regulate room temperatures with radiators in central heating systems reduces wasted energy.
EEM18 (Domestic Hot Water (DHW) Systems Efficiency): Using an efficient hot water system. This means the hot water system needs to have an efficiency higher than the standard electric water heater to qualify for a saving. Different types of hot water systems are discussed such as heat pump water heaters, boilers, and solar water heaters.
EEM19 (Domestic Hot Water Preheating Systems): This is about reusing waste heat to preheat water before it goes into the hot water system.
EEM20 (Economizers): Using economizers in the HVAC system to reduce the need for mechanical cooling during periods when external air is cool enough to be used for cooling.
EEM21 (Demand Contol Ventilation using CO2 Sensors): This measures how mechanical ventilation in a building can be controlled using CO2 sensors to maintain air quality and reduce unnecessary energy use.
EEM22 (Efficient Lighting for Internal Spaces): Using high-efficiency LED lighting inside a building.
EEM23 (Efficient Lighting for External Spaces): Using high-efficient LED lighting for external spaces, typically in buildings with multiple light sources.
EEM24 (Lighting Controls): Controlling lights using technologies like occupancy sensors, timer controls, or daylight sensors.
EEM25 (Skylights): Utilizing natural daylight from skylights to reduce reliance on artificial lighting during daytime hours.
EEM26 (Demand Control Ventilation for Parking Spaces Using CO2 Sensors): This measure involves using sensors to control ventilation systems in parking garages, specifically in principal areas and covering least 50% of the building.
**EEM27 (Insulation for Cold Storage Envelope):**Using the actual U-values for the insulation types and the respective construction elements in the energy tab in the software.
EEM28 (Efficient Refrigeration for Cold Storage): Using energy-efficient refrigeration in cold storage spaces, such as supermarkets.
EEM29 (Efficient Refrigerators and Clothes Washing Machines): Installing energy-efficient refrigerators and washing machines based on established standards.
EEM30 (Submeters for Heating and/or Cooling Systems): Using dedicated submeters for heating and cooling systems.
EEM31 (Smart Meters for Energy): Using smart meters installed for each unit of the building.
EEM32 (Power Factor Corrections): Installing voltage stabilizers or similar devices to improve the quality and efficiency of incoming current.
EEM33 (Onsite Renewable Energy): This describes how having onsite renewable energy reduces reliance on imported energy.
EEM34 (Additional Energy Saving Measures): Describes how additional energy-saving measures that are not included in the predefined list can be used. The project needs a request to get specific permissions to claim these strategies.
EEM35 (Offsite Renewable Energy Procurement): This measure details how procuring renewable energy from sources outside the building site can count toward building sustainability.
EEM36 (Carbon Offsets): This measure defines how investing in carbon offset projects can improve a building's sustainability profile.
EEM37 (Low-Impact Refrigerants): Using refrigerants with a low global warming potential (GWP) in refrigeration systems to reduce environmental impact.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

This quiz explores the impact of the Window to Wall Ratio (WWR) on energy efficiency in building designs. Questions address the benefits and drawbacks of various WWR scenarios, as well as the role of glass and Variable Speed Drives (VSDs) in optimizing energy performance. Test your knowledge on design goals, climate influences, and effective management strategies for sustainable architecture.