Water, Lighting, and Sustainability in Building Design

What is the purpose of a building's plumbing system?

To provide potable water, remove liquid waste, and control stormwater.

What is the water table?

The level below which the ground is saturated with water.

What is meant by the term potable water?

Water that is safe to drink.

What are the primary sources for the supply of potable water?

Surface water and groundwater.

Why are wells used for potable water?

When a place is too far from a municipal water source.

What is meant by domestic cold water (DCW) and domestic hot water (DHW)?

Cold or hot water used in buildings for domestic purposes such as drinking, food preparation, sanitation, and personal hygiene.

How is pressure provided to the potable water system?

Gravity via elevated water towers, active pumping systems in municipal systems, or pressurized bladder tanks in well systems.

What are the advantages of centralized hot water production?

More efficient for larger buildings, lower upfront cost than multiple units, easier maintenance.

What are the disadvantages of centralized hot water production?

Heat loss through long pipe runs, longer wait times for hot water, wastes water while waiting for it to heat up.

What are the advantages of point-of-use hot water systems?

Instant hot water, minimal heat loss, saves water.

What are the disadvantages of point-of-use hot water systems?

Higher upfront cost, more maintenance, can be less efficient if poorly distributed.

What are the pros of gas-fired hot water systems?

Lower operating cost, heats water quickly, good for high demand.

What are the cons of gas-fired hot water systems?

Requires venting and gas lines, produces emissions, more complex installations.

What are the pros of electric resistance hot water systems?

Simple installation, low upfront cost, no combustion.

What are the cons of electric resistance hot water systems?

High operating cost, less efficient overall energy use.

What are the pros of heat pump water heaters?

Very energy efficient, lower operating cost over time, can dehumidify surrounding space.

What are the cons of heat pump water heaters?

Higher upfront cost, slower heating rate, performance depends on ambient temperature.

What are the pros of solar thermal hot water systems?

Renewable energy source, very low operating cost, reduces environmental impact.

What are the cons of solar thermal hot water systems?

High upfront cost, weather dependent, requires backup system.

What are the basic components of domestic water distribution in small buildings?

Water main, water meter, hot water tank, piping.

What is the purpose of the water main?

Brings water from the municipal supply into the building.

What is the purpose of the water meter?

Measures water usage for billing.

What is the purpose of the hot water tank?

Heats and stores hot water.

What is the purpose of piping in water distribution?

Distributes hot and cold water to fixtures throughout the building.

What are the advantages of trunk and branch systems?

Lower material cost, simple traditional layout.

What are the disadvantages of trunk and branch systems?

Pressure drops when multiple fixtures are used, longer wait times for hot water, more joints leading to potential leaks.

What are the advantages of home run systems?

Consistent pressure at fixtures, fewer fittings reducing leakage risk, faster hot water delivery.

What are the disadvantages of home run systems?

Higher material cost, requires a central manifold, more piping overall.

What considerations must be given to water supply piping to prevent freezing?

Insulate pipes, keep pipes inside thermal envelope, maintain minimum indoor temperature, use heat tracing if necessary.

Why is it important to prevent pipes from freezing?

Water expands when it freezes, which can cause pipes to burst, leading to costly damage and system failure.

What portion of total household water use does irrigation comprise?

30-35%.

What strategies could be implemented to reduce water usage for irrigation?

Use drought-tolerant native plants, install drip irrigation, water during early morning or evening, use rain sensors or smart irrigation controllers, reduce lawn area.

What is meant by rainwater harvesting?

The collection of rainwater for non-potable uses.

What is greywater?

Wastewater generated from wash basins, showers, and baths, which can be recycled on-site.

What is blackwater?

Wastewater containing fecal matter and urine; i.e., sewage.

What is greywater harvesting?

The collection of greywater to reuse in situations like flushing toilets or watering plants.

What is the difference between sanitary waste and stormwater?

Sanitary waste originates from human activities, while stormwater results from heavy rain or snow.

What is the purpose of the air gap in plumbing fixtures?

To ensure the physical separation of water supply and waste systems, preventing contamination.

What is the purpose of the trap in waste piping?

To collect a water seal that prevents sewer gases from venting into the building.

What is meant by the term 'fall' in plumbing design?

The proper slope or pitch of a pipe for adequate drainage.

What are the basic components of sanitary drainage design in buildings?

Traps, vents, stacks, sweeps, clean-outs.

What criteria might guide the quantity and types of fixtures in a building?

Building usage, number of occupants, water efficiency, code requirements, ADA compliance, peak demand.

What are the basic components of an on-site sewage treatment system?

Septic tank, drain field, piping network.

What are the reasons for using a septic or aerobic system?

Used where centralized sewer systems are unavailable, treats wastewater onsite, reduces infrastructure costs.

What are the basic components of an alternative sewage treatment system?

Plants, microorganisms, soil, water channels or tanks, filtration and aeration zones.

What are the reasons for using alternative sewage treatment systems?

Use natural processes to treat wastewater, lower energy use, provide environmental benefits.

Why is it necessary to control stormwater?

To prevent flooding, erosion, and pollution.

What are the benefits of stormwater management?

Prevents flooding and property damage, reduces erosion and infrastructure strain, limits pollution entering natural waterways, maintains natural hydronic cycles, prevents overwhelming sewer systems.

What problems arise from using a combined storm/sanitary sewer system?

Overflow during heavy rain, untreated sewage and backups into buildings, public health risks, higher treatment costs, system overload and backups into buildings.

How is stormwater removed from a building's roof?

Roof slopes direct water to drains or gutters, which collect and channel water to downspouts that carry it to ground drainage systems or storm sewer.

What are alternative methods for removing stormwater?

Pervious paving, bioswales, stormwater gardens, green roofs, detention/retention basins.

Why use alternative stormwater management methods?

Reduce runoff and flooding, improve water quality through filtration, recharge groundwater, reduce load on municipal systems, provide ecological and aesthetic benefits.

What is luminous flux?

The power with which light is emitted from a lamp.

What is efficacy in lighting?

The ratio of light output (in lumens) to energy (in watts).

What does candlepower measure?

The intensity of a beam of light in any direction.

What is illuminance?

The quality of light emitted by a light source that lands on a given surface area.

What is luminance?

The intensity of the emitted light from a given surface.

What is brightness?

The subjective sensation that the viewer experiences when looking at an object or a surface.

What is reflectance?

The amount of light falling on a surface that is reflected.

What is transmittance?

The amount of light falling on a surface that is transmitted through that surface.

What is glare?

Difficulty seeing in the presence of bright light.

How does color temperature affect light quality?

Measured in kelvin, lower values indicate warmer colors, and higher values indicate cooler colors, affecting mood and perception of space.

What is the color-rendering index (CRI)?

A measure of how accurately a light source reveals the true colors of objects compared to natural daylight, on a scale of 0-100.

Why is proper use of daylight important in lighting design?

Reduces energy use, improves visual comfort and quality of space, supports sustainability.

What are the biological effects of daylight?

Regulates circadian rhythms, improves mood, focus, and productivity, supports vitamin D production; lack of daylight can cause fatigue and depression.

How can light be used in architectural design?

Highlights form, texture, and material, shapes spatial experience, guides circulation, changes perception of scale, creates focal points.

What are the sources of daylight?

Direct sunlight, diffuse skylight, and reflected light.

How does glazing impact daylight?

Controls how much light and heat enter a building; properties include Visible Transmittance (VT), Solar Heat Gain Coefficient (SHGC), and U-value.

What is the Light-to-Solar-Gain (LSG) ratio?

The ratio of visible light transmitted through glazing to the amount of solar heat gain; a higher LSG means more daylight with less unwanted heat.

What is daylight harvesting?

A system that uses sensors to reduce or turn off artificial lighting when sufficient daylight is available, saving energy.

What are the differences between incandescent, discharge, and solid-state lighting?

Incandescent: light from heated filament; Discharge: light from electric current through gas; Solid-state (LED): light from electron movement in semiconductors.

What is solid-state lighting?

Light from electron movement in semiconductors.

How does LED lighting compare in efficiency and heat output?

LED has high efficiency and low heat output.

What are the characteristics of incandescent lighting?

Warm light, high CRI, low efficiency, short life, used in residential/decorative.

What are the characteristics of fluorescent lighting?

Moderate CRI, medium efficiency, used in offices/schools.

What are the characteristics of metal halide lighting?

Good CRI, high output, used in large spaces.

What are the characteristics of high-pressure sodium lighting?

Poor CRI, very efficient, used in street lighting.

What are the characteristics of LED lighting?

High CRI, very efficient, long life, used almost everywhere.

What is a luminaire?

A complete lighting unit including lamp, housing, and controls.

What is the purpose of a luminaire?

It determines light distribution, efficiency, and glare control.

What is direct lighting?

Light aimed downward for tasks.

What is indirect lighting?

Light reflected off the ceiling for diffuse lighting.

What is semi-indirect lighting?

Mostly upward with some downward light.

What is direct-indirect lighting?

Balanced up and down lighting.

What level of illuminance is needed for transient activities?

~8 foot-candles.

What level of illuminance is needed for simple tasks?

~15 foot-candles.

What level of illuminance is needed for demanding tasks?

~30 foot-candles.

What is general lighting?

Overall lighting.

What is localized lighting?

Specific areas lighting.

What is ambient lighting?

Background lighting.

What is task lighting?

Focused lighting.

What is accent lighting?

Highlights features.

What is decorative lighting?

Aesthetic lighting.

What is architectural lighting?

Lighting integrated into the building design.

What are sustainable considerations for exterior building lighting?

Reduce light pollution and minimize harm to wildlife.

What is the relationship described by Ohm's Law?

Current equals voltage divided by resistance (I=E/R).

What is direct current (DC)?

Electricity that flows in one direction.

What is alternating current (AC)?

Electricity that alternates direction.

What is the difference between single-phase and three-phase power?

Single-phase is used in residential buildings; three-phase is more efficient for large buildings.

What is a series circuit?

A circuit with one path; failure stops the entire circuit.