APES Home Design: active and passive systems

• passive vs. active: define
  
• why is passive better?
  
• How can you tell active from passive? Which systems fail with no power
  
• cost? benefits? intangibles?
  
• Extreme examples: elab vs. typical office building
  
• Points for including each of these into your design
  
• Research and include newer solutions (e.g. PV windows)

Passive design:

• air-ventilation
  
• water
  
• lighting
  
• heating-cooling
  
• energy
  
• waste

Elab examples:

Passive air flow: 

• using airfoil design, pulls air out of building
  
• horizontal louvers drop dust and mist while channelling air upwards along surface (laminar flow)
  
• Stack effect: hot air rises, pulls air up and out
  
• air exchange per hour to reduce CO2 (ACH)
  
• try: place your house in a  natural air flow (valley, peak)

Passive water capture:

• Rain water capture on three roofs, one vertical, two horizontal
  
• gravity feed to tank
  
• solar powered pump
  
• solar powered UV purification
  
• pressure driven filtration
  
• green roof to capture and slow water (transit time)
  
• drip irrigation to preserve green areas, reduce temperature and evaporation
  
• evaporative cooling (EtO)
  
• low flow faucets and toilets
  
• bottled water to meet county regs (arsenic)
  
• grey water where possible (plants, irrigation)
  
• try: orient your house to capture rain or mist

Passive lighting:

• orientation: south to capture light, depends on latitude
  
• north facing skylights to capture light, not heat
  
• diffusers to soften light, reduce heat and shadows
  
• south facing windows with shades as needed to modulate
  
• light colored floors and paints to reflect light inside
  
• try: orient your home to maximize passive lighting

Passive heating-cooling:

• South facing windows with shades
  
• large thermal mass foundation, 180° phase change for heat
  
• west facing walls to capture heat for night
  
• wind driven air exchange 
  
• sensible heat: air flow reduces perceived temp
  
• 12” soy foam insulation on roof
  
• insulation inside all walls
  
• Low E double glazed glass
  
• sound insulation panels for comfort, lighting, acoustics
  
• insulated floor tiles for sound
  
• heat exchangers where needed (e.g. AK, UAE)
  
• fiber siding reduces heat flow
  
• metal roof: reflects heat
  
• Overhang: reduces direct solar 
  
• sealed doors in HVAC rooms
  
• periodic heating audit to locate heating-cooling leaks
  
• try: adjustable ventilation, heat exchangers

Passive energy:

• Thermal panels with thermosiphon flow for hot water
  
• Passive solar PV panels for energy
  
• Lithium battery storage for night 
  
• Wind turbines for cloudy augmentation
  
• EMC system to detect, reduce passive loads
  
• EV charging system below
  
• try: passive solar thermal first

Passive waste: 

• Gravity flow to bioreactor
  
• Low flow faucets and toilets to preserve water capture
  
• try: local biodegradation
  

Elab active systems: all solar powered

Air: 

• Thermal radiative cooling system, with solar pump
  
• Fans for air flow, augments stack effect
  
• HVAC filtration where needed
  

Water:

• Water pressure system: solar powered
  
• Forced water purification system, solar powered
  

Lighting:

• LED bulbs with occupancy sensors and timers
  
• Daylight sensors for exterior lights
  
• manual control for events, astronomy
  

Heating-cooling:

• High SEER heat pumps for heating, cooling (HVAC)
  

Energy:

• pump driven solar thermal system (demo downstairs)
  

Waste:

• motor driven digester (if needed)

Typical building systems:

• Air: very little air flow, sick building syndrome, toxic materials
  
• Water: no local capture, dependent on city water
  
• Lighting: incandescent, sodium (yellow), or CFL, harsh spectrum
  
• Heating-cooling: HVAC systems (pumps, radiators, AC)
  
• Energy: no local capture, dependent on city systems (HELLCO)
  
• Waste: dependent on city systems

NYC is an example, but offsets all of these active systems, with concentrated, efficient stacking of humans

Next: materials

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