BLDG SYSTEMS Flashcards
HARD WATER
water with a higher concentration of calcium and magnesium salts - water collects these minerals as it flows over rocks or through wells.
hard water usually tastes good and deposits little scale in pipes as long as it is cold - heated hard water is more active chemically and quickly encrusts interior surfaces of both water heater and hot-water pipes.
difficult to lather with soap, can cause ‘limescale’
us geological survey: 121mg CaCo3 / L water is hard water
WATER SOFTENER
used in bldgs served with ‘hard water’ - helps prevent scaling of pipes
simple ion-exchange column installed on the pipe that feeds the water heater to replace the calcium ions from hard water and replaces with soluble sodium ions
GROUND LEVEL HAND PUMP
useful up to 25’
a pump at ground level can create a sufficient vacuum in its intake pipe that atmospheric pressure will force the water through the pipe to the surface
SOFT WATER
has yet to collect the many minerals that hard water has.
soft water may be fresh rainwater - freshly evaporated water is soft as it leaves oceans and streams and leaves behind the heavier minerals.
US geological survey defines soft water as
anything less than 61mg of CaCo3 (calcium carbonate) per 1 Liter of water
BIOREMEDIATION
passing city sewage effluent through ponds with selected aquatic plants feed on the nutrients and absorb heavy metals and other poisons
some treatment plants use this process to create usable fertilizer
SEPTIC TANK
used in rural areas w/o municipal waste system
configured to hold sewage for a period of days, allowing it to decompose anaerobically and to separate into a clear, relatively harmless liquid effluent and a small amount of solid mineral matter which settles to the bottom
the effluent then runs out of the tank and into a leaching field - a system of porous pipes or tanks from which it is allowed to seep into the soil
sludge from the bottom of the tank must be pumped out every few years to be hauled away and processed into harmlessness at a remote treatment plant
SOILS
POROSITY
the amount of pore space in a soil and is related to grain size distribution and consolidation
BONNET or PLENUM
The chamber at the top of a furnace from which ducts of sheet metal or fiberglass emerge to conduct heated or conditioned air to the inhabited spaces of a building
LEADERS in DUCTWORK
the ducts that convey warm air from a furnace to a stack or branch duct
STACKS, convey warm air from a leader vertically to a register on upper floors
ZEROTH LAW of THERMODYNAMICS
says that no heat is transferred between two objects in thermal equilibrium; therefore, they are the same temperature
CALCULATING HEAT RELEASED/ABSORBED
q = m X C X (delta)T
where
c = specific heat capacity
m = mass of the substance
deltaT = change in temperature
MANIFOLD
section of ductwork with several outlets for making multiple connections
