Mechanical, Electrical, & Plumbing Systems

NOMENCALTURE

E = energy (W-hr)
I = electrical current (A)
P = electrical power (W)
pf = power factor

1) what is a net zero structure?
2) which fossil fuel is the most efficient?
3) what is natural gas's heating value?
4) what gas can be used when natural gas is not available & what is it's heating value?

1) b/c oil is a petroleum product, what are the disadvantages?
2) what are the 6 grades of oil for resi & commercial heating?
3) ^ which grades are for resi/ light commercial & what is the heating value?
4) & grade used for large commercial?

1) what are the advg's of using electricity?
2) the disadvantages?

1) what type of heating is electricity ideal for?
2) what is one of the most common uses w/ electric heating?
3) what is electricity's heating value?

1) steam is used as a bi-product in urban locations & campuses from generating electricity & is typ used for:
1) what is a heat pump?

SUMMER CYCLE OF HEAT PUMP
1) acts as a std. air conditioner
2) refrigerant circulates inside the heat pump thru a cycle that includes an evaporator & condenser
3) in the evaporator, the refrigerant absorbs heat from the inside air

1) how is the winter cycle different than summer in a heat pump?
2) what is the disadvantage of a heat pump when the outside temp is 40F or less?
3) to increase efficiency for a heat pump, it can be connected to:

1) how does a solar energy system work w/ a heat pump?
2) if system set up to use heat pump & solar energy, heat pump only turns on at what temp after too cold for solar
3) what else can supplement a heat pump when temp is very cold

1) best sources of natural energy are:
2) the fuel needed for heating can be estimated w/ "degree days," what is this?
3) how "heating degree days" calc'd?

1) how are "cooling degree days" calc'd?
2) natural gas efficiency (__)% :
3) propane efficiency
4) no. 2 oil efficiency
5) anthracite coal efficiency
6) electricity efficiency

1) any type of fuel must be converted to:
2) distribution of fuel thru a bldg typ req.'s
3) 2 of the most common devices for converting fuel to heat are:
4) what are the 3 types furnaces come in?

1) how to furnaces heat air?

1) what occurs in an "upflow furnace?"
2) in a "downflow furnace?"
3) in a "horizontal furnace?"

1) a boiler uses fuel to create:
2) what can fuel source of boiler be?
3) how is heat created in boiler?
4) if fuel for boiler is electricity or steam, then there is no need for:

1) what are the 2 refrigeration processes that can produce chilled air or water?
2) in some climates, what is a 3rd option?

1) what is "compressive refrigeration?"
2) ^ how does it work?

1) refrigerant that was banned
2) common refrigerant now used
3) friendlier environment options for refrigerant

1) what are the 3 fundamental components of a compressive refrigeration system?
2) describe the process of a compressive refrigeration system:

1) for small cooling units, how is air cooled that's to be circulated thru rooms?
2) what is a more efficient medium than air for carrying heat?
3) in large bldg's, air is typ cooled when water is pumped over the (__) coils & then this chilled water is pumped to:
4) to release heat, water in the pipes draw heat from the:

1) refrigeration by "absorption" produced chilled water thru:
2) evaporation by absorption is produced in a:
3) what is used to draw water vapor from the evaporator?

1) water that is boiled off is returned to a liquid state in:
2) what removes the waste heat & carries it to cooling towers?
3) compared to compressive systems, absorption systems are:

1) "evaporative cooling" occurs when water is dropped over:
2) as the free water evaporates (as vapor), heat is:
3) why does this only work in hot-arid climates?

1) why can evaporative cooling be more economical than refrigeration cooling?
2) a "ton of refrigeration" aka a ton of cooling, is a unit to describe:
3) needed capacity of a refrigeration machine in tons can be calc's by:

HVAC: ALL AIR SYSTEMS
1) what is a "direct expansion (DX) system" aka an incremental unit?
2) can a DX system also provide heat?
3) what is an "all-air system?"

1) all-air systems move heat to & from a space w/ supply & return ducts, & the most basic type of all-air systems is the:
2) where are these systems typ used?
3) describe the process of this system type

1) what is the disadvantage of this system?
2) what are the 4 main types of all-air systems used in larger bldg's?

1) in a variable air volume system, air is:
2) a thermostat ctrls a damper that varies the:
3) when outdoor cond's make it unnecessary to mech cond. the air, dampers on the return air side allow:

1) a VAV system is limited in its ability to compensate for:
2) a VAV system offers an efficient means of:
3) how is a high-velocity dual-duct system set up?

1) why can ducts be smaller in this system & therefore better for space saving?
2) why can the dual-duct system respond to varying req.'s thru the bldg?
3) what are the disadvantages of a dual-duct system?

1) in a reheat (constant vol.) system:
2) how do individual spaces receive air?

1) how is reheating air accomplished?
2) if the reheat equip. is located near the conditioned space, the unit is called:
3) if the reheating coils are located in the ductwork that serves an entire zone, the unit is called:
4) ^ how is temp regulated in #3
5) what is an economizer cycle & when is it used?

1) what are the advg's of the reheat system?
2) what is the disadvantage?

1) in a "multizone system" air is supplied to a central mixing unit where:
2) just like in a dual-duct system, the advantage of a multizone system is:
3) the main disadvantage is that the amt of duct space:
4) this type of system is only used for (__) sized bldgs, or where:

HVAC: ALL WATER SYSTEMS
1) an "all-water system" uses
2) ventilation is provided by:
3) in a two-pipe system hot or chilled water is pumped thru:
4) in a four-pipe system (Fig17.4):

1) in a three-pipe system:
2) is an all-water system an efficient way to transfer heat?
3) how/why is it easily ctrl'd?
4) it's not possible to ctrl what at the central unit?

HVAC: AIR-WATER SYSTEMS
1) this system relies on a central air system to provide:
2) when/where are these systems typ used?

1) in an "induction system" Fig17.5a, air is supplied thru the bldg how?
2) how is the water supply system for induction delivered?
3) another air-water system uses a fan coil for primary heating & cooling, but has a separate air supply to prvd:

HVAC: ELECTRIC SYSTEMS
1) the most common method of electric heating uses a:
2) advg's to electric heating are:
3) the biggest disadvantage of electric heat is that:
4) typ electric heat is used for supplemental heating in:

GREAT TABLE 17.2

-selecting an appropriate HVAC system for a bldg depends on:
1) use profile of the bldg (occupancies)
2) bldg scale

1) some occupancies need flexible systems for different req's of multiple tenants; VAV & induction systems satisfy this req., a bldg w/ multi uses of simultaneous variations in heating & cooling loads may need dual-duct or multizone sytems; hospitals & labs need induction or fan coil systems w/ supplementary air so supply is 100% OSA w/ complete exhaust to outside

3) some bldg's like hotels, apt's, offices need thermostatic ctrl over individual spaces, oth's like theaters need less
4) selecting an HVAC system according to which fuel is readily & economically available

6) flexibility for bldgs that may change occ. or added onto would benefit from an all-water or all-air system that can be size to accommodate end capacity
7) the initial cost of an HVAC system, long-term maintenance, & cost of operating the system must be considered; needs life-cycle cost analysis

-per IMC, req's for exhaust systems are distinct from ventilation req's; dedicated systems may be needed for:
1) equip that produce or throw off dust or particles sufficiently light to float in the air
2) equip that emit heat, odors, fumes, spray, gas, or smoke in quantities irritating or injurious to health/ safety

1) exhaust air must be discharged where?
2) exhaust air cannot be discharged into:
3) determination of exact distances from general HVAC exhaust outlets & air intake is left up to:
*see table 17.3 for distances of things to exhaust outlets

1) how much energy is typ used by HVAC systems in overall consumption of bldg
2) what was enacted to est. min efficiency std.'s for heating & cooling equip?
3) performance of this equip ^ is rated based on:

MECH TECH. TO CONSERVE ENERGY
1) an "economizer cycle" uses outdoor air when:
2) in "dual-condenser cooling," refrigeration equip uses:
3) ^(2) when heat is needed in the bldg (__) is used, & when it is not:

1) what is a sim. alt. that can be used like a dual-condenser cooling system?
2) "absorption chillers" compared to A/C chillers, don't rely on:

1) absorption chillers can be more efficient when using "solar-powered absorption cooling" b/c:
2) alt type of solar-powered cooling is the "solar-powered desiccant cooling" that uses:

1) "direct contact water heaters" operate by
2) to improve efficiency, what is added?
3) when inlet water temp is blw 59F, what is efficiency of system?
4) b/c it's a high cost alt, it's best used where there's a continuous demand for:

1) a "recuperative gas boiler" aka fuel or boiler economizer, recovers the heat in:
2) the reclaimed heat is used to preheat:
3) std. gas boilers max efficiency = 83%, what is the economizer one?

1) "displacement ventilation" is an air distribution system in which supply air is:
2) this system is only good for new const., why?

1) a "water-loop heat pump system" uses:
2) why does no additional energy need to be added or removed when heating & cooling modes are balanced?

1) when is it good to use this type of system?
2) what is advg over 2 & 4-pipe systems?
3) "thermal energy storage" uses (__) to store excess heat or coolness for use at a later time

1) what does thermal storage make possible?
2) ex, in summer chillers cool water at night when:
3) what medium can absorb & give off more heat, both sensible & latent?

HEAT TRANSFER
1) in order to better IAQ, more OSA is needed, but that causes a need for:
2) "energy recovery ventilators" aka air-to-air heat exchangers, reclaim:
3) ^these can reduce energy needed to cond. incoming air by:

1) why are these efficient in very cold, hot, or humid climates?
2) what type of bldgs are they most efficient in?

3 Cond's req'd for recovery ventilators:
1) fresh air intake must be kept far away from exhaust outlet as possible to avoid sucking exhaust back into bldg
2) exhaust air that contains excessive moisture, grease, oth contaminant should be separated from heat exchanger air

1) what 3 common devices are used to facilitate air-to-air heat exchange?
2) a "flat-plate heat recovery unit" is:

1) an "energy transfer wheel" aka enthalpy heat exchanger, transfers heat btwn:
2) what is the advg of the wheel exchanger over others?
3) some units have a transfer efficiency of:

1) how does the energy transfer wheel exchange heat?

1) a "heat pipe" is a self-contained device that:
* to work, pipes need incoming & outgoing airstreams to be adjacent

1) "water-to-water heat exchangers" aka runaround coils, use water or oth liquid to exchange heat by:
2) do incoming & exhaust airstreams need to be adjacent?
3) the efficiency of water-to-water heat exchangers is:

1) an "extract-air window" uses a double-paned insulated glass unit, w/ another pane placed inside the bldg, so air can be:

1) "ground-coupled heat exchangers" heat or cool outside air by:
2) in the summer, the air can be used directly if:
3) in the winter, the system can preheat air for:
4) they're suitable only for what bldg type

1) their disadvantage is that:
2) an alt to this type of system is the ground-source heat pump that uses:
3) a "chilled beam" is a clg mtd unit that uses (__) to prvd:
4) a "passive chilled beam system" relies on

1) explain how passive chilled beams cool air:
2) separate ventilation ducts are req.'d b/c no ventilation air is used, but this separation allows for:

1) why does this system allow a bldg's central chillers to be small than usual which saves energy?
2) in an "active chilled beam system" a ventilation system is integrated so it can prvd:
3) explain how an active system works

1) what is a "multiservice chilled beam system?"
2) chilled beams have a high initial cost, but what are the advg's?

1) a "variable refrigerant flow system" uses a single compressor & condenser unit outside, connected to:
2) refrigerant is supplied to:
3) each evaporator is:
4) how is power consumption reduced?

1) VRF systems can be designed to incorporate oth systems like:
2) VRF is ideal for bldg types:
3) it's not ideal for bldg types:

1) what are the advg's of VRF?
2) what is a "building automation system" (BAS)?

1) BAS can manage systems for:
2) the energy conservation component of a BAS is:
3) ^it detects enviro cond.'s in & out of bldg, monitors status of all equip like (__), & optimizes ctrl of equip by:

ELECTRICAL FUNDAMENTALS
1) "ampere" (amp or A) = unit flow of electrons in a conductor = 6.241 x10^18 electrons passing a given section in 1 sec
2) "energy" = product of power & time, aka "work"
3) "impedance" = resistance in an alternating current (AC) circuit in ohms

6) "reactance" = part of the electrical resistance in an alternating current circuit, caused by inductance & capacitance

1) what is electricity?
2) a basic electric circuit consists of a:
3) what is used to interrupt a circuit?

1) Ohm's law for DC circuits states the current in a circuit is directly proportional to the voltage & inversely proportional to the resistance, what is the equation?

*DC (direct current)

1) "power" is the rate at which work is done or at which energy is used (expressed in watts), what is the equation?

1) a useful mnemonic is PIE which stands for:
2) AC (alternating currents) circuits operate when a:

1) how is a voltage of alternating polarity produced w/ a conductor?
2) how is AC voltage represented graphically?
3) ^amplitude of wave represents:
4) distance btwn peaks represents:
5) frequency is measured in:

1) in AC circuits, resistance is known as:
2) the difference in voltage & current is represented by the:

1) Ohm's law for AC circuits, what is the equation?

1) what is the equation for power in an AC circuit? (remember it's sim to DC circuits)

2) what is the power factor for circuits w/ only resistive loads like incandescent lights or electric heating elements?

1) energy can be measured in (__) but is more commonly measured in:
2) what is the equation for calc'g the energy used in a system?

1) what are the 2 basic types of electric circuits?
2) describe how a series circuit works

1) describe how a parallel circuit works
2) adding up the individual currents in a parallel circuit results in:
3) why are series circuits not used in bldg const.?

MATERIALS
1) what is the basic mat. of an electrical system?
2) when the AWG number designation decreases, the conductor:
3) what is considered "cable?"
4) what is considered "wire?"

1) how is the cable diameter represented?
2) the current-carrying capacity or a conductor's "ampacity" depends on:
3) what are the 2 most common conductors?
4) why are specialists req.'d to install aluminum conductors?

1) what is conduit & what is the purpose
2) what type of cable is used in wood-frame resi bldgs of 3 or less stories?
3) what is the most common type of wire & cable?

1) when tapping into high currents is involved, what is used to avoid high $$?
2) what is req.'d for commercial & large resi const.?
3) what are the 3 types of metal conduit?

1) what is "rigid steel conduit?"
2) what is "intermediate mtl conduit?" IMC
3) what is "electric metallic tubing?" EMT

1) # of conductors in single conduit is limited to ctrl heat build up & depends on:
2) the (NEC) National Electrical Code sets limits on:
3) when would underfloor raceways or undercarpet cable be used?
4) what are the 2 types of raceways?

1) "underfloor ducts" are steel raceways that are:

1) "cellular mtl floors" use sim concept but
2) the most common form of elec. energy used in bldgs is "alternating current" AC, so when is "direct current" DC used?
2) utility companies prvd power to property lines, it's the owner's responsibility to then:

1) service to a bldg may be underground (more $) or overhead, when it's overhead:
2) when might it be more cost effective for the owner of a bldg to purchase a transformer?

1) what electrical wiring system is most commonly used for residences & small bldgs?
2) systems common for larger bldgs?
3) for larger bldgs typ w/ fluorescent lights which can use smaller wiring & currents
4) very large bldgs & factories w/ much machinery

1) what are "transformers" used for?
2) what is a transformer's unit of measure?
3) for cooling, transformers can be:
4) if possibility of fire like w/ oil-filled transformers, equip must be placed in:

1) what must be prvd'd at a bldg's service entrance?
2) in add. to total energy used, energy co.'s levy energy charges also based on:
3) most utility co.'s charge based on

1) what is "load factor?"
2) what does a low load factor mean?
3) what do all these terms mean: load ctrl, load shedding, peak demand ctrl, peak load regulation

1) how does load ctrl work? esp w/ automatic systems
2) how does load scheduling work & help?

1) large bldgs need a:
2) equip like transformers, meters, switchgears may req. a room that is:
3) power that comes thru the meter & transformer is:

1) b/c power from utility co. isn't always a steady, regulated voltage, what is used to help?
2) what is a "harmonic current" & why are they a problem for bldgs w/ computers & electronic equip?

1) where do harmonic currents come from? 2) what can prevent them?
3) in "active line cond.'g" a comp. analyzing the harmonics of a line voltage adds a:

1) secondary distribution is when power from main switchgear is distributed to individual panelboards where it's further:
2) how is a circuit protected?
3) how many amperes is typ for gen. lighting & power vs for large loads?

1) what are the 3 kinds of protection for electric circuits?
2) what is "grounding?"
3) to achieve grounding, the ground & neutral wire are both grounded at bldg's service entrance to a:

1) what are "ground fault circuit interrupters (GFCIs)" or "ground fault interrupters (GFIs)?"
2) where are GFI's req.'d?

1) what is an "arc-fault circuit interrupter" (AFCI)?
2) where are AFCIs req.'d?

1) the most common receptacle for normal distribution is the:
2) special outlets are req.'d for objects like:
3) what does it mean to be "hardwired?"
4) duplex outlets have holes to supply power, but also a 3rd hole for:

1) what is a "split-wired receptacle?"
2) outlets are typ mtd vert how high abv flr
3) ^but what is the min mtg ht req.'d for forward & side reach accessibility (ADA)?
4) in resi const. outlets must be a min (__) apart

1) most resi duplex outlets are (__) amps
2) outlets serving kitchen countertops must
3) on counters, how far apart are outlets?
4) do outlets in kitchen need to be GFIs?

1) what is a "two-way" switch?
2) what is a "three-way" switch?
3) a "four-way" switch?

1) switches can also be made low-voltage operated on 24V instead of line-voltage on 120V, the 4 advantages are:

1) what is a "power line carrier system" (PLC)?
2) what is req.'d by model & energy conservation codes to ctrl lighting?

1) what are some methods used to prvd multiple levels of illuminance?
2) specific req.'s for switching can vary by jurisdiction, but most req.'s are sim to ANSI/ASHRAE/IES Std. 90.1 Energy Std. for Bldgs Except Low-Rise Resi Bldgs which req.'s:

1-3) methods to accomplish auto shutoff:

*exceptions include areas w/ 24hr operations, spaces w/ patient care needed, or it would endanger safety/ security of room or occupants

1) Std. 90.1 req.'s every space enclosed by clg ht walls have at least:
2) where is a manual switch not req.'d?
3) when a manual switch for override is req.'d, it must:
4) device must not ctrl area more than (_)SF

1) add.'l ctrls are req.'d for uses:
2) why must fluorescent & incandescent lights not be on a single circuit together?

1) emergency power is supplied by generators or batteries for electrical systems that relate to:
2) standby power provides electricity for functions that:

1) 2 of the most common sources of large water supplies for cities are:
2) to treat water, its pH level must be known, what are the types?

1) what is "hardness" of water & what is the problem with it?
2) what is "turbidity" in water?
3) how are odor problems in water treated?
4) how are water color problems treated?
5) color & odor problems are caused from:

1) biological contamination in water can be caused by:
2) chemical contamination comes from:
3) water treatment methods are categorized into what 4 groups?

1) pretreatment is typ necessary before oth methods & used to:
2) 1st "sedimentation" uses gravity & still water to allow particles to sink before:
3) "coagulation" is the process of getting particles in water to stick together by:
4) "flocculation" is last where water & alum mix is sent to still water so:

FILTRATION
1) "slow sand filtration" allows water to seep thru a bed of fine sand 3-4ft deep to:
2) "direct filtration" passes water under pressure thru a filter medium, this process always includes:

1) "packaged filtration" is same as direct filtration except all elements are:
2) "diatomaceous earth filtration" uses a thin layer of diatomaceous earth on septum or filter element to:
3) "membrane filtration" forces water at high pressure thru a thin membrane that:

1) "cartridge filtration" uses self-contained units placed along the water supply line to:
DEMINERALIZATION
2) what does demineralization remove?
3) "ion exchange" is used in water softeners to treat hard water & to remove:

1) "reverse osmosis" removes contaminants by using a semipermeable embrane that allows only:
2) "electrodialysis" places charged membranes at the inflow stream of water to:

DISINFECTION
1) disinfection destroys what in water?
2) "chlorination" is most common treatment to kill organisms by:
3) "chloramine" is sim to chlorination but:

1) "ozonation" disinfects water thru the use of:
2) "ultraviolet light" destroys a cell's ability to reproduce & is effective against:
3) "nanofiltration" uses filter membranes that are capable of trapping particles:

1) "distillation" is treated by:
2) "aeration" or "oxidation" is used to improve:
3) process of aeration works by expsing as much of waer as possible to air thru:

1) if you want a private water supply in the form of a well, two important considerations in drilling are:
2) what yield is needed for a private residence
3) what protects well water from seepage of surface contamination?

1) pump systems used in wells have 3 fundamental components:
2) "suction pumps" are only good for water tables (__)ft
3) "jet pumps" can operate at depths from:
4) "turbine pumps" are used for:
5) common pump for residences is:

1) "jet pumps" have pump & motor abv grd to:
2) "pressure tanks" are used to maintain a constant water pressure for use in:

1) once municipal water supply has been treated, it's:
2) one of the 1st tasks in bldg a project is to determine the location of:
3) ^ where can this information be found?

1) why does the designer need to know the pressure in the line?
SOLAR WATER HEATING
2) how is an "open-loop system" aka a direct system defined?
3) in a "closed-loop system" aka an indirect system:

1) what is the adv vs disadvantage btwn the 2 systems?
2) "passive circulation systems" rely on what?
3) passive systems are simple & low cost, but their storage tanks must be placed:

1) "active circulation systems" use:
2) how can freezing be avoided in systems?
3) a "bach system" heats water directly in a:

1) a "thermosiphon system" relies on the:
2) in this system ^ where are storage tanks located?
3) ^ how does this system avoid freezing?

1) in a "closed-loop active system" a separate, nonfreezing fluid is circulated by pumps thru the solar collectors &:
2) a sensor is included to track temp when:
3) a "drain-down system" is a direct, active system that solves the freezing problem by:

1) a "drain-back system" is an indirect, active system that uses water as the heat-collector fluid, so heated water is pumped to a heat exchanger where:
2) a "phase change system" uses a phase change mat. as collector fluid b/c: