Building Services Applications: Ventilation, Heating Systems, Lighting

BUILDING SERVICES
APPLICATIONS
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Table of Contents
Questions A – Natural and Mechanical Ventilation..........................................................................3
Calculation of Heat flow..................................................................................................................3
Measures to improve the control of summer time temperatures..................................................4
Design of Duct..................................................................................................................................4
Schematic of a duct..........................................................................................................................5
Duct sizes for the system.................................................................................................................5
Pressure drop through the system..................................................................................................6
Questions B – Heating Systems...........................................................................................................6
Calculation of heating coil load......................................................................................................6
Schematic of Heater.........................................................................................................................7
Question C – Lighting.........................................................................................................................7
User requirement specification for the building............................................................................7
Electric lighting of the composite lab design.................................................................................8
Specification sheet for the types of fittings:...................................................................................8
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Questions A – Natural and Mechanical Ventilation
Calculation of Heat flow
Standard U-value for thermal elements
S.No. Element Area weighted U-value
1. Wall 0.28
2. Atceilinglevel,Pitched Roof with insulation 0.16
3. Atrafterlevel, Pitched Roof with insulation 0.18
4. Integralinsulation included flat roof/ roof 0.18
5. Floor 0.22
6. Basin of the swimming Pool 0.25
Total U – Value 1.27
Heat flow is calculated as
For North = 82 m2
Q=U x Area x Cooling load
¿ 1.27 W −m2 x 82m2 x 136 W −m−2
¿ 1.4163 x 105 Joules
For West = 24 m2
Q=U x Area x Cooling load
¿ 1.27 W −m2 x 24 m2 x 136 W −m−2
¿ 4.145 x 105 Joules
The height from the soffit of the space to the outlet of the stack = 8m
T 1=280 C
T 2=250 C
Cross sectional area required for the shaft in order to maintain an internal temperature is
given as,
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q=−k T 1−T2
L
Heat flux under one – dimensional, steady –state condition is constant and is given as,
k =1W /m
q=1 x 28−(−25)
8 =6.625 W /m2
Reference: Duct Designing in Air conditioning system and its Impact on System Performance
Measures to improve the control of summer time temperatures
Observation of field measurement
High temperature is observed during summer. This is mainly due to land management
practices which affects the stream temperature either in direct form or in an indirect form.
Logging and livestock grazing reduces the stream temperature which in turn maintains the
temperature to a level and not exceeding the limit (Amoako-Attah and B-Jahromi, 2016).
Thermal modelling
When building are in free space, there is no control over it. In order to protect the building
from thermal exploitation, in-door set points must be restricted based on energy saving
policies. As a result high relative performance of the building is achieved.
Generation of current
A high electricity demand occurs during summer. As a result the electricity load increases
with high temperature. A model is created with temperature projections in the conductors so
that a relative change with the safe operating temperature is maintained.
Design of Duct
Flow required for each arm = 75l/s
Pressure drop on each arm = 50Pa
Connection spigot duct size = 200mm diameter
Air duct velocity is given by
V =q/ A
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