Building Physics Actual

How to convert from C to Kelvin

add 231 (on formula sheet)

What is retrofitting?

Adding new technology to an existing building to enhance its performance.

Eg, HVAC,

What is the fabric first approach?

Method of retrofit.

1) Fix existing building fabric - eg install insulation, natural ventilation methods, improve door sealants.

2) Install mechanical systems - eg HVAC, boilers, heat pumps

3) Address energy demand - eg install solar panels

Two types of condensation

1) Surface - cold, impervious surfaces below dew point

2) Interstitial - between building fabric

How to reduce condensation (3)

1) Improve ventilation - remove moist air

2) Increase temp - above dew point

3) Insulation

3 ways to express sound levels - describe & units

1) Pressure - force exerted by sound wave over area (N/m2)

2) Intensity - energy over given area (W/m2)

3) Power - rate sound energy is produced at source

From this given equation, what are the other potential coefficients

Speherical = 11

Hemispherical = 8

Linear = Lw - 10logr - 5

How to calculate intensity of spherical, hemi and linear propagation (using this eq) and I = W/A

photo is for spherical

SA of hemi = 2pir2

SA of linear = pi r

Sound absorption coefficient

How much sound can be absorbed over frequency range

Hard surface = 0

Porous surface = 1

Total absorption of a room

Average absorption coefficient

Reverberation time - dif formulas

Sabine Assumptions: sound equally distributed, low absorption

Con - if large absorption then overestimates RT

Norris - log term allows for higher coefficients

shows sound doesnt decay linearly

3 advantages of daylighting

1) reduced energy demand

2) ↑ mental health and productivity

3) better visual quality

Formula for U value of a pipe

Luminous Flux (F)

Total light emitted by source in ALL DIRECTIONS

unit: lumen

Luminous Intensity (I)

Total light emitted by source in A PARTICULAR DIRECTION

unit: candela

Illuminance (E)

Amount of light falling onto a surface

Unit: lux

Luminance

Amount of light perceived in a SPECIFIC direction

how much light EMITTED FROM surface

unitL candela/m2

Mian sources of noise through a partition

Flanking sound - transmission of sound into recieving room not via partition.

Eg, floors, celinings, pipes

Good sound insulation (4)

1) Heavyweight - hevier structures = ↓ transmission

2) Completeness - no air gaps

3) Flexibility - ↑ stiffness - ↓resonance

4) Isolation - loss of sound energy at material junctions (provide adequate sealants)

Common sound loss areas in buildings (3)

• badly fitted/lightweight doors

• single glazed windows

• poorly sealed windows, partitions, service entries

How to reduce traffic noise

1) Reduce noise at source - ↓ vehicles, softer roads

2) Barriers

3) Reduce noise on route - soft landscaping

4) Buildings - glazing, sealants, rooms far from road

Diagram for components of Daylight Factor

What is PSALI

• Balances artificial light with daylighting - provide good light distribution across a room

• Maintains daylighting benefits w/out heat losses

3 PSALI considerations

1) Light distribution - gradual increase to windows

2) Control circuits - artificial at night

3) Lamp colour choice - match daylighting