Objectives

The primary objective is to appoint a qualified service provider to complete the installation of a refrigeration-based HVAC system for the Dry Room within the Seedbank Facility at the Kirstenbosch National Botanical Garden. The project aims to establish a stable, low-temperature, and controlled-humidity environment essential for long-term seed storage and handling, while simultaneously executing minor repair and maintenance works across the facility.

Scope of Work

The contractor will be responsible for the complete supply, installation, testing, commissioning, and handover of a new mechanical and electrical HVAC-refrigeration system. Key activities include:

• Supplying and installing a low-temperature condensing unit and a factory-built double-skin DX Air Handling Unit (AHU) with integrated cooling coil, electric heater bank, plug fan, HEPA filtration, heat recovery, and control systems.
• Installing copper refrigeration pipework, insulation, pipe trays, valves, driers, solenoid valves, electronic expansion components, and associated accessories.
• Executing electrical power cabling, control panel wiring, isolators, circuit protection, over-/under-voltage protection, and communication interfaces.
• Performing insulated ductwork tie-ins, structural supports, mounting frames, condensate drainage, hoisting, and rigging.
• Safely removing and disposing of existing redundant AHU, condenser, and dehumidifier units.
• Carrying out additional minor construction works, including VRV and freezer room repairs, door repairs, plumbing, hydroboil replacement, monitoring system installation, and making good all affected building surfaces.

Technical Requirements

The installation must comply with stringent engineering, safety, and environmental standards:

• System Performance: Maintain an airflow of 303 L/s, cooling duty ≥20.89 kW, off-coil temperature of –10.4°C, and evaporating temperature of –27°C using R410A refrigerant (~18.5 kg charge).
• Standards & Compliance: All materials and workmanship must adhere to SANS, ASME, EN, ISO, and relevant SABS codes (e.g., SABS 0400, SABS 0142, SABS 044 for welding, SABS 934/763 for galvanizing). Equipment must comply with international environmental protocols regarding refrigerant usage.
• Installation Specifications: Strict requirements for vibration isolation, acoustic damping, galvanized steel fabrication, surface preparation, painting, and welding quality. All exposed mild steel must be hot-dip galvanized; painted surfaces must follow specified colour-coding and primer/topcoat sequences.
• Testing & Commissioning: Comprehensive functional, pressure, airflow, and electrical tests must be witnessed by the Engineer. Calibration certificates for all test instruments are mandatory. Systems must operate within ±5% of specified performance figures after a seven-day trial period.
• Documentation & Handover: Submission of builder’s, general arrangement, shop, and as-built drawings; comprehensive O&M manuals; plant logbooks; spare parts lists; special tools; and statutory Certificates of Compliance for electrical and refrigeration installations.
• Warranty: A 12-month guarantee covering all defects in materials and workmanship, including monthly inspections and full servicing.

Skills & Personnel Requirements

Tenderers must demonstrate specific corporate qualifications and register key personnel:

• Company Registration: CIDB contractor grading of 3ME or higher, valid Central Supplier Database (CSD) registration, and a Letter of Good Standing from the Compensation Commissioner (COIDA).
• Key Personnel: A Category B SARACCA/SAQCC registered Refrigeration Mechanic serving as Site Foreman, with verifiable experience in commercial/industrial HVAC and refrigeration plants. A professional Contract/Project Manager registered with SACPCMP or ECSA. A professional Construction Health & Safety Officer registered with SACPCMP.
• Experience: Submission of up to five similar completed projects within the last ten years, supported by appointment letters, completion certificates, commissioning reports, and signed SARACCA/SAQCC Gas Certificates of Conformance.
• Financial & Administrative: Proof of liability insurance, financial references, and completion of all returnable tender schedules, including the Equipment Offered schedule with corresponding manufacturer datasheets.

Notes on Unusual or Complicated Terms

• Two-Envelope System: Tenders must be submitted in separate sealed envelopes: one for the Financial Proposal (pricing only) and one for the Technical Proposal (methodology, personnel, equipment specs, excluding pricing). Mixing pricing into the technical envelope results in immediate disqualification.
• Kyoto Protocol Constraints: Bids involving refrigerants classified under chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), or hydrofluorocarbons (HFCs) must strictly adhere to international phase-out schedules and global warming potential limits. Non-compliant equipment must be explicitly declared in writing.
• SARACCA/SAQCC Gas Certification: Contractors must provide a Gas Certificate of Conformance signed by a registered refrigeration mechanic for each referenced project, verifying legal handling and charging of refrigerants in accordance with South African regulatory frameworks.
• Credit for Removal of Valuable Materials: Existing redundant equipment deemed serviceable or unused carries residual value. Contractors must submit negative (credit) pricing for these items rather than positive charges, acknowledging their salvage or reuse value.