Thermal Bridges

Question 1

Thermal bridge

Answer 1

Section of insulated structure that has less insulation than overall design I typically occur in building joints when different constructions are joined together.

Question 2

Thermal bridge definition

Answer 2

Smaller area of the building envelope which the heat flow is increased due to a change in material, thickness,or geometry of the construction part

Question 3

Thermal bridges lead to:

Answer 3

Increase the transmission of heat loss, lower internal surface temperatures for constructions - poor indoor climate (drafts) - contamination of surfaces ( dust condensation) - moisture damage ( mold growth-fungi)

Question 4

TB can be categorized according to

Answer 4

1- typology —2 location

Question 5

Typology

Answer 5

1_ geometric TB
2- connective TB
3- constructive TB
4- systematic TB.

Question 6

Location

Answer 6

1 _ geometric TB.
2- TB conditioned by material.
3- combined TB.
4- constructive TB.
5- Air bridges.
6- TB conditioned by environment.

Question 7

Geometrical TB

Answer 7

Occur due to changes in the shape of the structure like building corners.

Question 8

Connective TB

Answer 8

Caused by unintentional air flows in a construction.
Examples in a cavitywall when the insulation doesn’t fill the cavity completely and in a wall/ roof joint where the wind can blow through part of the insulation.
Can be minimized by appropriate design and workmanship

Question 9

Convective TB occurrence

Answer 9

Joints between basement floor and wall - foundations - windows and doors - building corners - joints between floor slabs and wall- joints between the inner and outer balconies - joint between roof und external wall installations that penetrate the building envelope.

Question 10

Constructive TB

Answer 10

Occur when there are penetrationsof the insulation material in the building envelope - also occur at joints between exterior walls and windows and penetrations of the envelope by electrical installations, water pipes.

Question 11

Systematic TB

Answer 11

Attributed to the group of constructive thermal bridges - often represent small additional contribution to heat loss - could be wall binders or wood studs in walls. - occur repetitively

Question 12

Positions of TB

Answer 12

Corners of buildings-joints of internal and external wall -combination of wooden beams and rafters with reinforced concrete cerclages-connection of ceiling and outer wall - connection of wall and roof - connection of wall and floor - window and door joints - break through of insulatinglayers (balconies,consoles).

Question 13

The transmission heat losses are divided into

Answer 13

1- one-dimentional losses
2-two dimensional losses
3- three-dimentional losses.

Question 14

Air leakage

Answer 14

Uncontrolled air transferthrough enclosures markedlyincreases the energy required to heat, cool, control humidity in buildings - air leakage is a leading cause of moisture problems.

Question 15

Strategy to increase air lightness depends on factors

Answer 15

Building type- building structure of walls - window assembly - facade penetrations and their locations, level of existing insulation- air and vapor barrier.

Question 16

Air barriers

Answer 16

Systems of materials designed and constructedto control airflow between the conditioned and unconditional spaces.

Question 17

Arr barrier material selection depends on

Answer 17

Wall type-building use - building shape - local materials -material compatibility - climatic conditions -local contractor experience with specific materials

Question 18

Most used air barrier materials.

Answer 18

1- mechanically attached flexible sheets
2- spray applied polyurethane foam.
3- self adjusted sheet materials
4- fluid applied membranes

Question 19

Before starting minor renovations forT B and air leakagewe should:

Answer 19

-Make building enclosure assessment to determine the existing paths of air leakage in the redesign or planning phaseto improve envelope und mitigate airflow.
- results must be documented on drawings of the building and by pictures of existing conditions.
- open louvers, conduit penetrations, elevator, lift machine room shafts are places for air leakage.

Question 20

Ways to test air leakage

Answer 20

Infrared camera - smoke test - blower door

Question 21

Critical points for inspection of air barrier system;

Answer 21

Roof to wall transition- wall to foundation transition - penetrations - feneStrations- material transitions - access hatches - expansion joints - building corners- structural penetrations - wall type and control or air, barrier installation