Flashcards in Ballast - PPD Personal Cards Deck (191)
What is positive drainage?
Positive drainage is a slope that goes away from the building, parking area, and walkways.
Name the two systems of drainage systems and key elements of each.
Aboveground: pervious paving, sheet flow, gutters built into roadways and parking areas, ground swales as part of the landscaping, and channels to manage runoff and direct it appropriately.
Underground: use perforated drains and enclosed storm sewers to carry the runoff from the site, either to a municipal storm sewer system or to a natural drainage outlet such as a river.
What is sheet flow?
Water that drains across a sloping surface, whether that surface is paved, grassy, or otherwise landscaped.
Sheet flow is directed to gutters or channels.
What is the minimum slope needed for drainage?
1.5% is needed to account for paving roughness and variations in installation tolerances.
Although a slope as little as 0.5% may be sufficient for some drainage, this is only true fro very smooth, carefully constructed surfaces.
What is a catch basin and name a key element of it and why.
A catch basin is an underground reservoir.
It has a sump built into it which allows debris to settle into the sump instead of flowing down the sewer and potentially clogging the pipe.
What is a sump?
A sump is a low space that collects water and debris.
Define the runoff coefficient.
The fraction of water NOT absorbed.
What is a holding pond?
If the site development creates a volume of runoff in excess of the capacity of the existing municipal storm sewer or natural drainage course, a holding pond may be constructed on the site.
The holding pond collects the site runoff and releases it into the sewer system at a controlled rate.
What is the building sewer?
The portion of the horizontal piping of the sanitary sewer system outside the building.
What is the minimum slope of the building sewer?
0.5% - 2.0% depending on the size of the pipe.
A greater slope is required for smaller pipes.
The location of main electric lines may dictate what?
The location of transformers and service entry to the building.
How should roads in parking areas be laid out?
- So a driver can go directly to the parking area, to a drop-off area, or to the loading area without intersecting the roads to the other areas.
- Forcing traffic through the parking area to reach the loading area or a drop-off point should be avoided.
- A road should NOT be laid out perpendicular to a slop unless the slope is very gentle. The road should slightly cross the slope, to minimize the grade.
- A road should be limited to a maximum slope of 15% for short distances, although 10% or less is preferred.
- A road should have a gradual cross slope for drainage from the center of the roadway, called the crown, to the sides.
- If a road has a gutter it should be 6".
When are handrails required for ramps?
If the rise is greater than 6".
Handrails must extend 12" past the top and bottom of the ramp.
When are handrails required for stairs?
If over 4 risers or where icy conditions exist.
Handrails must extend 12" past the top, and 12" + one tread at the bottom.
What is the width of accessible parking stalls and its associated access aisle?
Standard: 8' stall width + 5' access aisle (13' total)
Van Option 1: 8' stall width + 8' access aisle (16' total)
Van Option 2: 11' stall width + 5' access aisle (16' total)
What are some benefits to landscaping, in addition to its pure aesthetic qualities?
- Can improve energy conservation;
- Moderate noise;
- Frame desirable views;
- block undesirable views;
- create privacy;
- fashion outdoor spaces;
- provide shade;
- retard erosion;
- visually connect a building to its site
What is a drip line, in regards to trees?
The edge of its canopy.
Contours of the land cannot be changed within the drip line of an existing tree.
What is the difference between a direct gain and indirect gain system (in reference to passive solar design)?
Direct gain systems collects heat through south facing glass and then stores the heat in high mass materials.
Indirect gain systems heat the mass by room air temperature and reflected sunlight.
A direct gain system will capture about 4 times as much energy as an indirect system with the same mass.
What is a roof pond?
A roof pond stores heat in large water-filled bags on the roof of a building.
Winter: During the day the bags heat up, at night the insulation is moved over the roof pond, and the bags release heat downward into the building.
Summer: During the day the bags are covered with insulation so that they absorb heat only from the building. At night, the insulation is removed and the absorbed heat is transferred upward and away from the building.
What are the three components that make up a typical active solar system?
- A collector: either a flat-plate collector or a focusing collector
- A storage device: water for water systems and rock beds for air systems, phase change materials can also be used, but they are more expensive
- A distribution system: same as for standard HVAC systems; ducts for air, pipes for water, and associated fans, pumps, registers, and control devices
What is the difference between an open-loop system and a closed-loop system?
An open-loop system, the water is heated directly in the solar collector.
In a closed-loop system, antifreeze or some other transfer medium is heated in the collector and circulated to a heat exchanger, where the domestic water is heated by the transfer medium.
For maximum energy generation, what should the tilt angle be for a PV system?
For most of the year, about the same as the latitude of the building.
During the winter, the tilt angle should be 10-15 degrees greater than the latitude.
Where is the best place for the entrance for the following climates:
- Cold: leeward side to avoid winter winds
- Temperate: south side to make them more inviting and to capitalize on the natural snow-melting effects of the sun.
- Hot: the long side of the building to catch cooling breezes.
Which has less surface area if the volume is the same: a square/cube or a rectangle?
A building with a _____ total surface area will generally use less energy.
What is the difference between an external-load dominated building and an internal-load dominated building?
An external-load dominated building (also called a skin-load dominated building) uses energy based mainly on the amount of heat loss or gain through its exterior envelope. (Examples: houses, apartments, condos, warehouses)
An internal-load dominated building uses energy driven by high heat gain from occupants, lighting and equipment. (Examples: offices, hospitals, retail stores, schools, and labs)
What is the best shape of building for:
- Cool zones
- Temperate zones
- Hot-arid zones
- Hot-humid zones
- Cool zones: square or cube
- Temperate zones: elongated in the east/west direction (1.5-2:1)
- Hot-arid zones: squarer shapes with courtyard
- Hot-humid zones: elongated in the east/west direction (3-4:1)
South-facing facades should have _____ louvers, while east- and west-facing facades should have _____ louvers.
What is superinsulation?
A technique of providing higher levels of insulation than normally used.
I.E: tightly sealing all joints and cracks, and preventing any thermal bridges between the outside and inside, such as through studs. All portions of the building are carefully detailed so that every piece is insulated.