Human behaviour-dependent and variable-flow-reversible mechanical ventilation system design in an underground parking facility

Abstract

Fixed air change ventilation in a huge underground parking facility is a major energy consumption for a building. Variable and unidirectional flow and control by carbon monoxide (CO) sensors in a parking facility can help to reduce energy consumption. However, obstructions in the parking facility reduce the effectiveness of uni-directional flow. Also, siting of CO sensors at particular positions may not accurately reflect the CO level throughout the whole parking facility. This study proposes two energy-efficient approaches. The first approach is to reduce the ventilation rate based on the number of cars, which is determined by a parking guidance system. The second approach is a reversible zonal control system in relation to the human behaviour. Parking bays near access lobbies are always favoured. This behaviour is used to determine ventilation zoning. For commercial buildings, cars are parked for long periods of time, where CO and heat generated by cars can be removed within a certain period of time. All fan shafts are designed for zonal control and reversible mode, dynamically operated to effectively remove hot and contaminated air. This reversible zonal control system can remove the heat effectively within a shorter time, thus improving energy savings.

The Impact of Exhaust Louvres and Emission Rates on The Effectiveness of Parking Lot Ventilation

“…Kong et al [18] proposed two approaches: reducing the rate of air circulation in proportion to the number of automobiles and adopting reversible zone control based on the location and appeal of parking spaces.…”

Implementation of demand-oriented ventilation with adjustable fan network

“…24 The aforementioned approaches enhance the occupancy positioning and source identification resulting in better HVAC operation control strategy. 25 With awareness of occupants’ state, the HVAC system can operate based on the real scenario and overcome its shortcomings such as conditioning unoccupied zones 26 or assuming maximum occupancy in spaces 27 regardless of the prevailing situation. Previous research has confirmed that the adjustment of the airflow diffusing directions can provide an average energy savings of around 59%.…”

Effects of Cross Level Air Interaction within Multilevel Underground Carparks on Indoor Air Quality

“…Car emissions might increase during start-up and at lower speed and health effects might become worse in poor ventilation, which make underground carparks not favorable for long-term stays [4,5]. Carpark users may become feel uncomfortable at temperatures of 32 • C to 35 • C and air velocity between 0.2 and 0.4 m/s for 80% satisfaction [6]. Therefore, a given underground carpark requires a proper ventilation system to maintain CO levels within acceptable limits in accordance with regulations and legislations of the related country [7].…”

“…Sittisak et al [26] initialized the single floor underground carpark (188 cars capacity) with 120 ppm of CO and reported that a 4 ACH of ducted system could reduce the concentration to 28 ppm after 15 min. Similarly, Kong et al [6] simulated an underground carpark with 300 parking bays where CO emissions from car were allowed for 3 min before being stopped and starting ventilation fans at full capacity. They reported that 2 ACH was found to be adequate to ventilate the space when 5% of cars are running and 6 ACH was required when 40% of cars are running.…”