Build-up Area

Riyadh – KSA
13,500 m2
Full MEP Design
Producing BOQ
HVAC System Design & Calculations
Full detailed AutoCAD Drawings – 2D Piping
Full Equipments Schedules & Schematics
Full Technical Report
M. M. Al-SABAGH for Architect.
Riyadh – KSA

Project consists of a modern furniture exhibition of two basements & three show floors with an annex & management floor (built-up area of 13,500m2). The HVAC was originally designed using VRV refregerant system but the consultant asked us to re-assess the system due to the major architectural issues; and after studying it we have redsigned the HVAC by using chilled water system after making a comparison between the two systems.
The comparison is actually between using many indivisual units versus AHUs since the project is of open nature. The main proof to this is that the chilled water system could use many individual units as well but such will keep most of the problems of the old system.

Comment on the original VRV system
• Having many individual FCUs above false ceiling (about 200 units) is causing the following:
 Many refregerant pipes spread across the whole building with future leakage detection problems.
 The need to have huge number of access panels for maintenance.
 The big number of FCUs will cause serious maintenance problems for cleaning the filters and normal maintenance issues.
 Many condensate pipes above false ceiling.
 Having many electrical power wiring serving FCUs with isolator switches for each.
 Also will have huge number of control wiring for FCUs with complicated network & maintenance.
• The used system cannot control humidity which is very important for furniture & wood.

Characterstics and advantages of the new HVAC system:
- The building was provided with complete HVAC system controlling internal air quality levels year-round via chilled water system.
The system includes chillers, AHUs with steam humidifiers, FCUs & chilled water circulation pumps. Each chiller have two seperate stages which allow flexible loading and power conservation at partial loads. Two sets of circulation pumps were provided to allow easy handling of variable thermal loads. Most chilled water pipes are on the roof which allow easy maintenance without affecting building & decoration.
- AHUs are installed on roof thus air supply to floors will be through air ducts with maximum possible even distribution which cancels acceess panels & leakage issues & wiring above false ceiling. Also this elemenate units' noise and provide equal cooling to building zones. Heating is provided via electric heaters installed inside AHUs & FCUs. - Exhaust fans are provided for toilets, pantries & stores to exhaust smells.
- Ventilation to pump rooms and services and electrical rooms was provided as needed.
- Car parking ventilation and exhaust was provided to achieve acceptable levels of fresh air & to prevent accumulation of vehicles' gases.
- Proper ventilation to special rooms was provided for furniture installtion and painting; with providing an option of 100% fresh air operation to AHUs which allows runing them when needed (after working hours) without cooling to ehaust the smells of new furniture, wood & paint inside the show rooms.
- HVAC units to switch off during fire.
- Smoke management system with smoke fans was provided according to civil defense requirements & NFPA.
- Stair case pressurisation for emergency exit stairs was provided according to civil defense requirements and NFPA.
- HVAC system was designed according to ASHRAE with cooling loads calculations using HAP software.