How to avoid mould in air conditioned buildings

moisture mould problems air conditioned buildings

In air conditioned buildings, the exterior vapour pressure will be higher than the vapour pressure in the air conditioned room, therefore the vapour and moisture flow is high to low (blue line in the diagram above)

Now normally this is not an issue, because a decent ventilation system will transport moisture back to the air conditioning cooling coil, it’s condensed, and safely drained away.

However, problems occur when a vapour retarder is installed (red line in above diagram) interrupting the flow. Moisture becomes trapped, and even the best ventilation system cannot transport it to the cooling coil. Instead what happens, damp, moisture, and then mould growth occurs (left of red line in diagram above).

wall-mould-800w-2

And we already know the problems associated with mould, it causes poor indoor air quality, and therefore health issues for the occupants. If the air conditioning room also happens to be under negative (relatively) pressure, as often occurs in hotel rooms, the situation is compounded because the vapour quantity is increased, accelerating the process. It should be taught in school “don’t ever use vinyl wallpaper in air conditioned buildings” because it causes mould.’

This phenomenon is not limited to Hong Kong, it occurs in hot tropical climates, whether you are in Singapore, Indonesia, Shanghai, or Hong Kong.

Furthermore, it’s the type of problem that’s not immediately apparent, mould doesn’t just appear overnight, and it is unlikely to surface within the defects liability period (DLP).

thermal-scan-101

So it is obvious, lining the external wall of an air conditioned space with any vapour retarder must be avoided at all costs. But sadly it still happens today, increasing maintenance and costs for building owners and operators.

About Kelcroft

Kelcroft based in Hong Kong provides specialist advice, including energy, built environment, and green building consulting services, advising owners and design teams, to lower the cost of building operations.

tags

#mould #mold #hongkong #buildings #hotels #maintenance

EMSD Cooling Tower Audit

emsd cooling tower audit, hong kong

In Hong Kong EMSD (www.emsd.gov.hk) requires an independent audit of cooling tower system every year, and still in 2016 it is needed. In the photo above the cooling tower basin is contaminated with dirty, and algae grow has started.

emsd cooling tower audit

Model air conditioning condenser side water schematic  credit: Prevention of Legionnaires’ Disease Code of Practice

The EMSD Code of Practice part 2 is the standard to assess the cooling tower system operation, and the annually conducted audit requires document review of the procedures and a physical inspection of the towers inside and out, then adjudicate compliance.

cooling tower audit hong kong

cooling-tower-hongkong-600w

Cooling Tower FAQ

Q. Who can conduct EMSD cooling tower audit in Hong Kong?
A. Kelcroft conducts independent EMSD cooling tower audit for Government, and private sector organsations.

Q. Is on-site checking of the cooling tower system required?
A. Yes, site inspection of the cooling tower system and operating records is required.

Q. What cooling tower system records will be checked?
A. The cooling tower operation check include the records for maintenance, water treatment, and laboratory results shall be reviewed.

Q. When is EMSD Cooling tower audit required?
A. Annually and after any major renovation work is recommended.

Q. What standard is used for the cooling tower audit?
A. The cooling tower audit standard is the latest version of EMSD Code of Practice for Water Cooled Air Conditioning Systems Part 2: Operation and Maintenance of Cooling Towers [link]

CLICK HERE for information about Kelcroft’s EMSD cooling tower inspection

BEEO compliance for new construction by John A. Herbert

by John A. Herbert

emsd cocr stage 1

How to comply with BEEO ordinance for new construction?

To build in Hong Kong you follow the traditional BD submission format, but you must also fulfil the mandatory requirements detailed in the Building Energy Efficiency Code (BEEO). How does that impact the construction process?

The building owner must engage an EMSD Registered Energy Assessor (REA) to complete and issue EMSD Form EE1, also known as Stage 1 Certificate of Compliance Registration (COCR), and an EMSD Form EE2, known as Stage 2 COCR.

When does the COCR need to be issued?

Stage 1 COCR must be submitted within two months after obtaining BD consent. For Stage 2 COCR, that must be submitted within four months after obtaining BD Occupation permit.

further details are provided on the EMSD website.

hongkong-emsd-energy-code-2015-rev-a

John A. Herbert attended Eco Expo Asia 2015

Kelcroft’s director Mr John A. Herbert, attended the annual Eco Expo Asia 2015.

BEAM award for Mr John A. Herbert – Sept 2015

John A. Herbert John A. Herbert

Kelcroft in HK Trader Magazine by John A. Herbert

John Herbert interview published in Hong Kong Trader Magazine, Kelcroft

We are proud that Kelcroft’s John A. Herbert was featured in the HK trader magazine, he was interviewed about the future outlook for green and environmental products in the region.