What is the biggest percentage of energy demand in private housholds? - Space
heating 70%
space heating demand - net enery demand
of energy, which is required to heat a building.
independent of system or energy carrier.
Heating energy consumption - gross energy demand = net energy dem. / (heating)
system efficiency
takes into account production, storage, transmission and distribution of heat
Total energy consumption - = final energy consumption
= gross energy demand + hot water
+ lighting
+ electrical appliances
+ energy for operationability of heating system (pumps, fans, control system, ...)
Primary energy consumption - total energy consumption (for heating)
+ generation, conversion & distribution of energy carrier
(influence of system to which one is connected to produce the energy)
= total energy used to produce and transport the energy necessary for the building
Name 3 types of heating demand calculations. Describe what they are used for - 1. heat
load calculations
- design, plan & dimension the heating system
, 2. annual space heating demand
- determine amount of energy needed
3. transients
- time dependent behaviour (outside fluctuations influencing inside)
What parameters are needed for the heat load calculation? - reference temperature
(extreme outside temperature )
# and size of radiators
--> for dimensioning the heating system:
maximum heat load for a standardized reference indoor temperature
How is the annual space heating demand calculated? - Q_H = (Φ_T + Φ_V +
η(Φ_S+Φ_I)) * Δt
with η = use factor (how much can be utilized of gains)
What kind of heat losses does a house have? - transmission losses through surfaces
ventilation losses (introduce cooler air into heated space)
infiltration losses (leakage of cooler air inside / heated air outside) -> depends on
tightness of building
What does the magnitude of heat losses of a building depend on? - Temperature
difference (indoor outdoor)
ventilation & infiltration flow rates
area of walls, roof, floors, windows, ...
insulation level of building components
What is the protected (conditioned) building volume? - Volume where thermal comfort is
required and thus heating/cooling is implemented
≈ habited volume
calculated through use of external dimensions (incl. wall elements)
energy reference area - heated floor area of a building (in "thermal building")
(all heated above and underground floor areas)
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