C1- Heat Gain & Loss Flashcards
Thermal bridges:
Are _________ in a building with a very ______________________________.
areas
high thermal conductivity
Fabric heat loss:
Loss of heat via ____________ of _______________.
conduction
building materials
Ventilation Heat Loss:
Warm air escaping through ______ of a building.
gaps
In a busy office where doors keep opening and closing, the __________________________ will increase.
ventilation heat loss
Contribution of air change to heat loss:
Is the _______ of air inside a building being ___________.
rate
replaced
What is radiant heat?
Heat from a _________________ that __________ across a room.
hot stovetop
spreads
What are the 4 main factors of heat gain/loss?
1.
2.
3.
4.
- Insulation.
- Local climate.
- Temperature difference.
- Building use.
What is the equation for fabric heat loss?
Fabric heat loss= U A x ΔT
What is U-value another word for?
Thermal transmittance
What is the equation for ventilation heat loss?
(v= ventilation rate C= specific heat capacity)
Ventilation heat loss= ρ x v x C x ΔT
In terms of air change rate,
What is the equation for ventilation heat loss?
(N= air change rate V= internal building volume)
Ventilation heat loss= 0.33 x N x V x ΔT
In older buildings, draught increases the exchange between warm interior air and cold exterior air leading to heat loss.
How do we carry out draught reduction?
Sealing gaps around windows and doors.
Traditionally, why are radiators installed near the floor?
Because cold air sinks towards the floor.
Low emissivity glass reduces heat loss by _____________________ back into a room.
reflecting radiant heat
How can air changes alter the temperature inside retail units with a glazed curtain wall:
The _______________ is ____________ by ____________________ from outside the building.
heated air
replaced
cold air entering
