HEALTH AND SAFETY
Table 1. Causes of condensation related to building envelope or design condition. Causes
Effects Cold surfaces meeting warm air Condensation forming on surfaces
Inadequate sealing of windows and doors Moisture entering indoors Building envelope air leaks
Cracks and unintentional openings Air leaks, moisture intrusion Moisture intrusion, mould growth
Non-vapour barrier materials with thermal Trapping moisture and promoting barrier properties – condensation absorption
mould growth
additional factors that contribute to condensation. By examining these tables, we gain valuable insights into the complexities of moisture-related issues in healthcare settings, helping us develop targeted strategies for prevention and mitigation.
Proactive approach MOH implements a comprehensive approach and multifaceted strategy to tackle condensation and mould issues within its healthcare facilities for the health and safety of patients, staff, and visitors. Firstly, MOH engineers and facility managers (FM) adopt internationally recognised guidelines and standards that provide clear instructions on designing, constructing, and maintaining healthcare environments to prevent condensation and mould growth. These guidelines encompass aspects like proper ventilation, moisture control, insulation, and building
materials. Prominent guidelines, standards, and a local case study in Table 4 provide insights for managing condensation and mould.
FMs conduct regular inspections and
proactive monitoring enabling early identification and swift mitigation to detect condensation and mould-prone areas. Infection control practices, including maintaining indoor air quality, hygiene protocols, and building upkeep, are emphasised. This is explicitly outlined in the facility management contract for government hospitals, which also mandates indoor air quality assessments. Trained professionals conduct comprehensive air quality tests, analysing humidity, temperature, ventilation, airborne particles, organic compounds, and mould spore counts. Detailed reports with results and recommendations guide follow-up actions, where facility management reviews, prioritises, assigns
Effects
Proposed mitigations
Improve insulation; seal air leaks Improve weather stripping; seal gaps Seal cracks and gaps
Seal cracks, identify and address intentional openings
Use vapour barrier coatings; Improve ventilation
responsibilities, and implements remedies. Continuous monitoring ensures ongoing air quality improvement to protect building occupants’ health. Engineers incorporate design elements
to minimise moisture accumulation, including drainage systems, moisture- resistant materials, and efficient mechanical, ventilation and air conditioning (MVAC) systems. This proactive approach is exemplified in Figure 5, which shows a retrofit project involving the installation of a new Air Handling Unit (AHU) equipped with an Outdoor Air (OA) dehumidification or preheating system – in the image, the AHU is seen integrated into the existing MVAC infrastructure; this innovative addition aims to address high humidity concerns by effectively drying the incoming outdoor air before the cooling process. Figure 6 showcases a new building project using PU panel insulative
Table 2. Causes of condensation related to defects related to mechanical cooling and ventilation of building. Causes
Leaky air ducts Creates suction that draws moist outdoor air from leaky building envelope Inadequate & inefficient dehumidification High or uneven indoor humidity levels Incorrect thermostat settings Chiller and blower miss synchronise Inconsistent cooling
Multiple FCUs operating at different schedules sharing the same outdoor
air intake ducting Frequent compressor cycling and
continuous air circulation with outdoor air supply
Temperature fluctuations
Effects of mis-synchronised chiller and blower
Variable temperature distribution
Upgrade or adjust dehumidification system; monitor humidity levels
Calibrate thermostat settings; maintain consistent temperature
Mitigations for mis-synchronised chiller and blower
Synchronise chiller and blower operations; maintain systems
Moisture migration from outdoor air duct Separate fresh air ducts for units with into room
varying schedules
Gradually increase indoor humidity levels and promote condensation on cold surfaces
Inadequate or poor ventilation leading to Can lead to condensation on surfaces, stagnant, moisture-laden air
Optimising compressor control and implementing demand-based ventilation strategies
Install exhaust fans, optimise
indoor air quality issues and discomfort ventilation system settings, for occupants
clean air filters IFHE DIGEST 2024 29
Proposed mitigations Seal air duct leaks
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