Sunday, June 21, 2009

Heating, Ventilating, Air-Conditioning (HVAC) System Types: Air and Water Systems

Heating, Ventilating, Air-Conditioning (HVAC) System Types: Air and Water Systems
from MEEB 9th ed.

air and water systems
General:
Several variations, most heating and cooling of each zone is accomplished via the water distribution tree
water distribution tree = Much thinner than tree needed by air.
Air quality = filtering, humidity, freshness achieved by small, centrally located conditioned airstream, equal to the total fresh air required, is provided.
Several distribution trees are involved, yet total space the require is still less than required for all air systems.
Exhaust air = may be gathered in a return air duct system, making heat recovery possible. OR, (cheaper alternative) air can be exhausted locally, to avoid the construction of yet another distribution tree.
Two-pipe system = Water distribution provides either heating OR cooling ONLY.
Four-pipe system = Provides simultaneous heating AND cooling.

air and water Induction systems:
Air terminals found below windows throughout the U.S., high velocity and high pressure, constant volume fresh air supply is brought to each terminal, where it is forced through an opening in such a way that air already within the room("bypass" or secondary, air) is induced to join the incoming jet of air.
Circulation = fairly thorough circulation of room air is accomplished with only a little centrally treated air.
Finned tubes = air passes over them for heating or cooling.
Thermostat = controls the unit's output by controlling either the flow of the water or the flow of secondary air.

air and water Fan-coil with supplementary air systems:
Fan-coil located below a window is typical, it moves the room air as it provides either heating or cooling.
Centrally conditioned, tempered fresh air is brought to the space in a constant-volume stream;the fan moves both fresh air room air across a coil that either heats or cools the air, as required.

Air and water Radiant panels with supplementary air systems:
Either ceiling or wall panels contain the heated or cooled water to provide a large surface for radiant heat exchange.
Centrally conditioned, tempered fresh air is brought to the space in a constant volume stream.
Equipment in the space consists of a large surface, which must be kept clear of obstructions to radiant heat exchange.

air and water, Water loop heat pump systems:
Variation on two-pipe distribution system.
Heat pumps (water-air) either draw heat from the loop (heating mode) or discharge heat to it (cooling mode).
For a large building in cold weather, excess heat of the interior zones is used to warm the perimeter zones.
Loop temp. ranges between 65-90 deg F.
In hot weather, a central cooling tower disposes of the loop's excess heat, whereas in cold weather a central boiler adds the loop's needed heat.
Due to use of individual heat pumps, this system is closely related to direct refrigerant systems.
Often considered an all water system.


2 comments:

  1. 3d bioprinting = Immortality = go to stars ((typewrite: interstellar travel constant acceleration))

    ReplyDelete
  2. (1)...space-elevator (orbital station ramp: fresh air)… CO2 + laser UV = C + O2... RENOVATOR AIR UNIT: Powerful-Compressør³ continuously extracting the air Only from bathrooms, air of ship enters into bathrooms by slots floor/ceiling level ((((air passes condenser metallic grid which has a cold extreme ship´s wall through at outer space, from centrifuge device water drops distilled go out centrifuged...air´s spiral@pipe goes to outer space sufficient for air cooling only till CO2 freezing point, their already solid ice particles go away into the air current centrifuged impacting against the wall of (with only narrow entrance´s branch increasing thus wind-speed, and double wall with hot circuit anti-freezing liquid for no ice adherence over wall) *U-Tube* of the air which *has exit in the U curve zone* to the roomy hollow on lateral wall of a *Cylinder-Tube*, perpendicular and centered, that has a, with solid axis at both sides running through all components, --╠---|PISTON|---╣-- *shoving the ice pieces at both ways goes -comes*; for isolate air current the same PISTON *at both sides* opens-closes Cylinder extremes on both *intersections* with U-Tube (with closed cylinder extreme, a pump makes *Vacuum* within cylinder: piston goes to extreme, of air and only remains the ice; piston comes to middle, of CO2 and only remains the vacuum, now other valve lets air come in, test it putting the finger on/off to a syringe, for equaling pressure in piston´s both sides), and shoves/releases *over extreme of this now hollow central axis* (length="T"╣branch-line´s ø) of a *Circular Cap valve*, how a mushroom with its stem hollow, which has on the back side a *spring* against cavity (for spring+Cap) in the wall of *another perpendicular Tube forming "T" at both sides*, 2 branch-lines, of the ╠*Cylinder-Tube*╣, from that another Tube *arrives from one side* hot CO2 current, this *drags towards the another side* and sublimates the ice...from ╠both branch-lines╣ which outlet into 1 only tube, gas CO2 passes now by a thin and long tube with mirror interior walls ╩╩╩╩ ╩╩ with inclined multiples discharges of laser rays UV ultra-short wave "of the vacuum"...finally C and separation of O2 which passes to ■Tank reservoir O2 liquid)))) --- extracting from the cold final of spiral@pipe the Compressør³ sends the dirty air, already without water nor CO2, compressed through anti-return retention´s ÷valve to 2 ©Deposits at outer space...besides punctually reinforcing, when sensor detects presence into bathroom connects extractor ~Ventilator of Pressure (220 v.ac/50 W) that carries the dirty air to a thermo-insulated graphene´s inflatable ºBalloon at outer space, another minor ~ventilator extracts the air of the ºBalloon and sends it to the beginning of spiral@pipe... Both ©Deposits have the dirty air already liquid at cryogenic temperature --- #DISTILLER Linde mini --- N and O2 ((someday will be obtained also Oxygen from (California University)...CO2 + laser UV ultra-short wave = C + O2... electrons of CO2 molecule are in covalent bond, shared, they acquire energy from photons of the UV laser jumping thus temporarily to higher orbits and breaking thus that now reactive photochemical CO2 molecule))… the dirty air remains that can´t be used is thrown to space...the 2 ©Deposits alternatively working, one close exit mode distilling, another open exit mode throwing; both have at entrance a solenoid┴valve, and exit´s hinged door slightly opens/closes with 1 motorized gyratory screw outside the ©Deposit --- █Tank Reservoir Air Liquid that receives, if it is necessary, also O2 from ■Tank reservoir O2 liquid… From █Tank Reservoir Air Liquid (N+O2) arrives more/less new air for maintaining the ambient pressure: »»» breeze of clean fresh air 1 bar »»»░... Finally shall smell to roses in a Spacecraft.

    ReplyDelete