HVAC Design Narrative

1 General

The system design, material and equipment shall in general comply with the following International Standards and local Government regulations:-
 International Building Codes (IBC)
 International Mechanical Codes (IMC)
 American Society of Heating Refrigerating and Air-Conditioning Engineers (ASHRAE)
 Sheet Metal and Air Conditioning Contractors’ National Association (SMACNA)
 National Fire Protection Association (NFPA)
 British Standards Institution (BSI)

2 Nature & Scope of System

2.1 Design Criteria

Indoor Condition : 23℃, 55% RH
Fresh air : 10 l/s per person
Population density : 5 sq.m/person

2.2 Description of system

Shop
Ceiling mount fan coil units with fresh air duct connection to return air plenum. Chilled water and condensate drain pipe will be provided for the fan coil units and connected to the landlord provisions at the vicinity of the shop. Power supply to the fan coil units will be fed from fuse spur units.










Sheet No. S021
3 Description of connection to Owner’s system

The connections to Owner’s system are summarized as below, which are subject to site coordination.

Type of connection Landlord Provision Size Design flow rate Proposed bottom level
1. Chilled water supply and return pipe Dia 50mm 1.45 l/s 4000 AFFL
2. Condensate drain pipe Dia 32mm Not applicable 4000 AFFL
3. Primary air duct 350mm x 250mm 370 l/s 4000 AFFL

Remarks : a/. 6 sets of FCU with air flow of 0.47 m 3/s and cooling capacity 8.5 kW are provided by Tenant.

4 Type of Insulation

The installation of duct / pipe insulation shall comply with the following criteria and standard:

 Duct insulation shall have a flame spread index not more than 25 and a smoke developed index not more than 50 when tested in accordance with ASTME84. It shall not flame, glow, smolder or smoke when tested in accordance with ASTMC411.

 Pipe insulation shall have a flame spread index not more than 25 and a smoke developed index not more than 450 when tested in accordance with ASTME84. It shall been FM approval mark.









Sheet No. S021

Services Nominal Size (mm) Type of material Minimum Thickness of Insulation (mm)
1. Chilled water pipes Upto 125mm Flexible elastomeric insulation 32
2. Condensate drain pipe Upto 50mm Flexible elastomeric insulation 15
3. Air-conditioned supply and pre-treated air ductwork in air-conditioned space All Semi-rigid fibre glass duct wrap
25mm (t), 32 kg/m³ 25

4. Air-conditioned supply and return air ductwork inside non-air conditioned space including ceiling void All Semi-rigid fibre glass duct wrap
25mm (t), 32 kg/m³ 25































Sheet No. S021
Grand Canal Shoppes Submission ( Unit No. 2812 ) –HVAC Design Narrative

5 Cooling Load Estimation
See below table.

MVAC Calculation

Room A/C Area (UFA) Cooling Load Design Criteria Cooling Load
　 (ft2) M2 kW / m2 (kW) (Ton)
　 　 　 　 　 　
General Retail Area 1938 180.11 0.22 39.6 11.3
　 　
　 　 　 　 　 　
Total Area 1938 180.11 Total Cooling Load 39.6 11.3
　 　 　 　 　 　
Room
Population
Exhaust Air
(EA)
Requirement General Exhaust Air
Qty
Fresh air (FA)
Requirement Fresh Air
Qty
Landlord
Provision Remark
　 Customer <1> Staff Customer +
Staff Air change
per hour l/s l/s per
people l/s FCU-10 Qty 　
　 　 　 　 　 　 　 　 　 　 　
General Retail Area 30 7 37 　 　 10.0 370 6 　
　 　 　 　 　 　 　 　 　 　 　
Total Area 30 7 37 Total Exhaust Air Flowrate (l/s) 0 Total Fresh Air Flowrate (l/s) 370 　 　 　
　 　 　 　 Design Airflow rate
(l/s) 0 Design Airflow rate
(l/s) 370 　 　 　
　 　 　 　 Landlord Provision 0 　 370 6 　


Minimum Chilled Water Pipe Size in mm 50
(Based on single source supply only)
Average Cooling Load Density in kW / m2 0.22









Sheet No. S021


6 Drawing List

Drawing No Rev. Size Drawing Title

S022 A A3 HVAC Layout

S023 A A3 Air/Water Side System Schematic

S024 A A3 Section