Here is a typical specification for a client who is proposing to use Hi-Velocity in a public library project. CHS provide many architects, M&E consultants with these detailed proposals.
SPECIFICATION
For
“Hi-Velocity” Heating and Cooling
To
Ground and First Floors
Section 1: Design Conditions
Section 2: General Description
Section 3: Equipment & Installation Specification
Section 4: Exclusions
Conditions of Sale
Delivery
Section 5: Drawing Schedule
Prepared by: Charles R Stark, MCIBS January 9 2008
On behalf of: Cooling & Heating Sales Ltd
Unit No 1, Wolves Farm
Wyatt’s Green, Doddinghurst
Essex. CM15 0QE
Tel: 0870 240 7629 Fax: 01277 356120
www.coolingandheating.info Email: sales@coolingandheating.info
Section 1
Design Conditions
Ambient Conditions
Maximum Summer Conditions
28ºC db18ºC wb
Minimum Winter Conditions
–3ºC Saturated
Room Conditions
Internal Design Temperature
23ºC ± 1 deg C (Summer)
at the point of control:
21ºC ± 1 deg C (Winter)
Cooling and Heating CapacitiesSystem 1
Quick Choice Fiction (G13)
Cooling 14.0 kW total
Heating 20.0 kW
System 2
Adults Library (F2)
Cooling 20.0 kW total
Heating 30.0 kW
System 3
Adult Library/Learning Resources (F8)
Cooling 14.0 kW total
Heating 20.0 kW
System 4
Adult Library (F10)
*Heating 20.0 kW
*Heating only with provision for retrofit, total cooling 14.0 kW.
Minimum number of HE type supply air outlets per system would be:-
System 1 — 24
System 2 — 23
System 3 —24
System 4 —24
Section 2
General Description
We would supply deliver, install and commission 4 No. Hi-Velocity ducted systems, generally as detailed in manufacturer’s literature. Each system would comprise a high velocity high pressure air handling unit incorporating a direct expansion refrigerant based heating/cooling coil, low pressure hot water heating coil fan and air filter. The air would be discharged via insulated and vapour sealed ductwork and 80 mm dia. flexible attenuators 3.5 m long, to ceiling, wall or floor outlets.
The outlets would discharge high velocity air to the treated areas. The high velocity creates a low pressure column which induces the room air to provide a virtually draft free system with minimal temperature gradient.The installation would be to Hi-Velocitiy’s recommended specification and standard. The refrigeration and electrical installation would be in accordance with Section 3 “Installation Specification”.
Each system would comprise a Hi-Velocity attenuated flexible return air duct to the plenum chamber on the air handling unit, where fresh air would be introduced. The mixed air would then be filtered heated or cooled at the dictates of a remote temperature sensor and discharged via insulated and vapour sealed Hi-Velocity “snap lock” ductwork to the HE 3.5 metre attenuators and discharged at high velocity via the supply valves. In addition the system serving the Adult Library would incorporate the existing attenuator.
In the Adult Library/Learning resources (F8), system reference 3, two separate temperature controlled zones would be available via on/off motorised dampers.
Systems 1, 2 and 3 would serve by a heat pump type inverter outdoor unit as manufactured by Messrs Diakin via a purpose made interface panel designed specifically for use with the Hi-Velocity system.
Interconnecting refrigerants and electrical services between the direct expansion coil and the outdoor unit would be in accordance with the equipment and installation specification—Section 3.
The systems would be installed generally as indicated on the drawings as scheduled.
Section 3
Installation Specification
Hi-Velocity Ventilation
General
All components for the air distribution system would be suitable for the air pressures and flow, with joints, supports and hangers in accordance with Hi-Velocity install literature. Operatives installing the systems would have attended a training course supervised by Cooling and Heating Sales Ltd.
Air Handling Unit
Each air handling unit would be Hi-Velocity model HE 101 capable of providing a maximum air flow of 519 l/sec @ 373 pa (external pressure) adjusted to match the specified capacities.
Distribution Ductwork
The distribution ductwork would be manufactured from galvanised sheet steel of the “Snap lock” type insulated and vapour sealed with patented Hi-Velocity insulation.
Outlets
Supply air outlets would be of the standard finish Hi-Velocity type HE either floor, wall, or ceiling mounted. The outlets would incorporate roughing boot and on/off air supply damper.
Attenuators
Supply air attenuators would be of the Hi-Velocity HE type 3.5 metres in length insulated and vapour sealed and constructed to a maximum rated pressure of 2.5 K pa.The existing attenuator serving the Adult Library (F8) would be reused on the return air to the Hi-Velocity unit serving the area. The remaining areas would incorporate a flexible Hi-Velocity attenuators.
Controls
An Aprileair controller together with sensors would be supplied and installed for each system/zone. The controller would provide temperature control and incorporate a time switch.
Refrigeration System
Refrigerant Pipe work
All components used for refrigerant pipe work would be suitable for the refrigerant and lubricant concerned, and would be kept free of all contaminants.
Setting Out
Refrigerant pipe work would be run in concealed locations within the building, where possible. The refrigerant pipe work would be neatly clipped to cable tray or on approved clip hanging installation system.Refrigerant pipe work would be so arranged as to avoid gas locking in liquid lines and liquid collection in gas lines. The pipe work would also be arranged so that any oil entrained in the refrigerant and not removed by any separator, will be carried through the system and back to the compressor.
Pipes
Refrigerant pipe work would be run in copper and would be of a refrigeration quality to BS 2871 Part 2.All copper tube would be fully degreased and cleaned internally.
Pipe Joints
Joints in copper pipes would be brazed. Brazing would be carried out in accordance with the HVCA Code of Practice—”Brazing and Bronze Welding of Copper Pipe and Sheet”. Whilst brazing joints, the inside of the pipe would be flooded with nitrogen to prevent the formation of oxides.Compression joints and screwed joints would not be used in refrigerant pipe work except at equipment accessories.
Pressure Testing
On completion and before operation, every refrigerant system would be proved tight by pressure testing.
Refrigerant—R410A
Leak tracing would be carried out only with dry nitrogen.
Charging
After testing and before charging, every refrigerant system would be thoroughly evacuated and dehydrated using a purpose-designed vacuum pump, with all valves in the refrigerant pipe work open.The charging line would be thoroughly cleaned and the correct quantity (by weight) of clean, dry refrigerant would be admitted.
Insulation
Gas and liquid line pipe work would be insulated using closed cell polymeric insulation such as Insultube by NMC Kenmore Ltd. or equivalent, fitted fully in accordance with the manufactures recommendations. The insulation would be class “O” fire rated.
Drain Lines
Condensate drain lines from the Hi-Velocity units would terminate in tundishes made available by others.
Electrical
Wiring
All the inter-connecting electrical wiring between the air cooled outdoor units, evaporators and automatic controls of the air conditioning systems would be carried out in accordance with the latest edition of the I.E.E. Wiring Regulations, and relevant British Standard specification or Codes of Practice, except where specified to the contrary.
The electrical supplies scheduled below would be required terminating at isolators adjacent to the units:-
1 No. 20amp 415v 50hz 3 phase Outdoor unit
3 No. 32amp 230v 50hz 1 phase Outdoor units
4 No. 16amp 230v 50hz 1 phase Air handling units
Section 4
Warranty
The entire installation would be covered by a 12 months warranty including parts and labour. The foregoing is subject to proper care without misuse and the equipment being under a scheduled maintenance agreement.
Exclusions
The following items are excluded:
- Removal of existing equipment.
- Negotiations associated with planning approval and landlord’s permission and English Heritage where applicable.
- Provision of scaffold or hoisting equipment.
- Builders work, structure alteration and redecoration.
- Mains electrical supplies.
Delivery
5/6 weeks from receipt of official order to proceed with full working drawings.
The installation period would be 30 working days (one pair of operatives).