HVAC
Industry standards increasingly reflect the need for active ventilation and indoor air quality management.
What about occupant wellness and what does the WELL standard advise?
The WELL Building Standard 1 is a pioneering building standard focused on enhancing human health and well-being through the built environment.
WELL is grounded in evidence-based research that demonstrates the significant impact that buildings can have on the health, satisfaction, and productivity of their occupants.
The people factor
Industry standards increasingly reflect the need for active ventilation and indoor air quality management. Guidelines such as ASHRAE 62.2 set minimum requirements for mechanical ventilation in residential buildings to maintain indoor air quality, recognising that natural infiltration is no longer sufficient in tightly sealed structures.
However, ventilation alone does not actively control humidity, particularly when in humid climates. This can leave a gap between compliance and performance.
According to Wynand Deyzel, Commercial Sales Manager at air treatment technology specialist Solenco, this is becoming a design consideration rather than a maintenance issue.
“ Specialists have become very good at controlling temperature, but moisture is often left unmanaged. In more airtight buildings, that moisture has nowhere to go, and over time it begins to affect everything from structural finishes to sensitive equipment. We are also seeing increasing demand for dedicated humidity control across hospitality, high-end residential, and light commercial environments, where standard HVAC designs do not fully address moisture management,” he says.
While air conditioning systems remove some moisture as part of the cooling process, they are not designed to directly control humidity levels. Air conditioners respond to temperature settings, cycling on and off to maintain a target temperature regardless of the relative humidity in the space. Dehumidifiers, by contrast, are designed to regulate moisture, maintaining a set humidity level independently of temperature. In practice, the two systems serve different functions and are most effective when used together rather than interchangeably.
This is where building design is starting to evolve. Environmental control is no longer limited to heating and cooling. Air itself is becoming part of the finished system, requiring active management to ensure stability over time.
The Building Standard recommends maintaining relative humidity( RH) levels between 30 % and 60 % in office buildings to support health and wellbeing. This range aligns with US Environmental Protection Agency( EPA) guidelines to minimise the growth of harmful microorganisms like mould and bacteria and other indoor air quality risk, which can multiply at RH levels above 60 %.
Ref 1: National Library of Medicine Indoor Air pub. 3 Dec 2021: https:// pmc. ncbi. nlm. nih. gov / articles / PMC10924614 /
Moisture control
“ Moisture control is no longer something that can be left to chance. It needs to be engineered as part of the space in the same way as temperature control, especially in environments where humidity is consistently high,” says Deyzel.
This is resulting in greater use of integrated dehumidification within building systems. Rather than acting as a corrective measure, dehumidifiers are increasingly being specified to maintain stable indoor conditions, reduce strain on HVAC systems, and protect long-term asset performance.
For developers and facility operators, this applies to both new builds and retrofits. Ceiling-mounted, inverter-driven systems can be incorporated into design plans or added to existing spaces to manage humidity without disrupting the building ' s overall aesthetic or energy profile.
As buildings continue to evolve towards greater efficiency, the unintended consequences of airtight design are becoming harder to ignore. Managing moisture is no longer a passive outcome of ventilation. It is an active design decision that will increasingly define how well buildings perform over time.
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