By Mike Mak Asset Enhancement 0 Comments

EV Parking vs Additional FSI

Demand for EV Charger facilities in existing (old) building carpark is definitely rising in the town. Many would focus on reliability of new power consumption, enhancement of infrastructure and how best to house those new facilities. In GBE, fire safety with respect to the additional fire load of EV charger facilities is also our key consideration on design and planning of project. Incorporation of smoke detection system, fire extinguisher, Direct Link connection and Fireman’s emergency switch, etc. are encouraged for the relevant project. Enhancement of client’s assets and upholding of high level of safety are one of our major deliverable to our clients.

By John Lam Asset Enhancement • Building Technology • Design 0 Comments

Part 2 : Coating materials for Aluminium cladding – Misery of “Self-cleaning”

Following with our part 1 discussion, we now share another hot topic about coating applied on the aluminium. “Self-cleaning” is indeed a merchants’ name . The behind sciences are varying from among different manufacturer. We have conducted some comparison among different materials being applied to the cladding surface.

Theory of “Self-cleaning”

Self-cleaning : Hydrophilic approach 

In short, there are a few theories behind the “self-cleaning” . One typical approach is to create the surface which reduce the water surface tension. When the water droplet lands on the surface, the water droplet has formed an wetting angle to the surface of cladding. The stronger the water tension, the more acute the wetting angle is. The below diagram explains the wetting angle and how it carries the dirt / stain / attachment on the surface. Different manufacturer has formulated different chemical materials to reduce the water tension and flatten the wetting angle. The water is to carry and flush away the dirt. The most typical chemical approach is to create the coating surface which offer better hydrophilic (hydrophilic is origin from latin word, the word philic means love).

 

 

Self-cleaning : Photo-catalytic Oxidation 

Another theory is by “Photo-catalytic Oxidation” . We are not Chemist and cannot cite the theory . Nevertheless, we found one extract from “Chemosphere 193( 2018-198-206)” ,  there explains the “photo-catalytic oxidation” with the below graphic. In short, it is the oxidation process to the VOCs by UV and Photon. This is again alleged by many peers as ” self – cleaning” , but obviously the theory is very different from “hydrophilic approach”

Self-cleaning : Hydrophilic approach

To the contrary of “Hydrophilic” , some manufacturer applied the opposite ; hydrophobic approach. The theory behind is to keep the strong water tension of the droplet and let the droplet to “PICK” the dirt away. From our very preliminary scanning , this technique was more relying on the water – repellent nature ,

Product in the market : – 

We have encountered different approaches in the market. All suggest their “self-cleaning” properties. We try to cite some examples to illustrate different theory behind . We are not in the position to comment each performance and indeed it is difficult to do comparison. We hope this articles can offer some ideas for future research

Kansai Paint : 

One of the product is made by Kasiai, we were given the understanding that the materials is silicon-based modified resin materials with their own additive untold to the public. This is to create the “Hydrophilic” by flush and deliver the dirt.

 

 

Hydrotech from TOTO

Hydrotect is the tradename by TOTO. We extract their self-allegation from their official website. In short, they claimed their coating technique is photocatalytic which is to OXIDE the VOCs in the air. Their website further suggests this “Hydrotect” can offer the hydrophilic surface to flush the dirt

XX Sheet film paper 

A manufacturer , named to be untold here, claimed that there film sheeting offer the self-cleaning. We cannot identify their theory online. Nevertheless, we did a quick water spray test on the surface. We noticed that the water droplet kept intact on the surface and did not appear wetting pattern which is for flushing the surface.  From the picture below, the water – droplet keeps visually keeps the sharp and the droplet drip pattern is in the form of line.

 

 

By Candy Yip Building Law • Building Technology • Design • Real Estate • 0 Comments

Fire Safety in Commercial Premises

Fire safety can be regarded as one of the primary considerations in building designs. The terms of fire safety cover a wide range of building concepts, ordinances, and regulations under the law. When we consider the fire safety works in banks, the concept of Fire Safety (Commercial Premises) Ordinance should not be omitted. The introduction of FS(CP)O is one of the ordinances which aims to provide better protection to the occupants and visitors on certain kinds of commercial premises.

Prescribed commercial premises and specified commercial buildings are under the scope of the ordinance.  For the captioned the premise, they are required to update that fire safety construction including means of escape, means of access, fire-resisting construction under the Code of Practice for the Provision of Means of Escape in Case of Fire 1996, Code of Practice for Fire Resisting Construction 1996, Code of Practice for the Provision of Means of Access for Firefighting and Rescue 1995 respectively. Also, the premises required to update fire services installation following Codes of Practice for Minimum Fire Service Installations and Equipment and Inspection, Testing, and Maintenance of Installations and Equipment 1994 when the total floor area exceeds 230 square meters.

As a building professional to cope with the above issue, a desktop study needs to be conducted first. It is essential to calculate the number/width of the exit door and exit route following the purposed usage of the premises. The comparison of the recorded plan and Fire Safety (Commercial Premises) Ordinance may draw attention to the fire safety deficiencies. The site visit is followed to identify the deficiencies. fire services system always associates with water supplies and electricity. For the aged building, some non-emergency services like electricity will be located in the exit route. However, those non-emergency services did not enclose by FRR materials. It may post a potential fire hazard. Insufficient width of the MOE route, insufficient number of exit routes to the required staircase, presence of the fire shutter in the exit route, absence of exit sign, absence of the exit door, etc are the common scenario for the aged commercial premises to deal with the ordinance. The reasons for the above deficiency can be caused by certain reasons including the change in use, the absence of the fire safety ordinance during the construction period, and unauthorized building works by the owners.

By samsontam@me.com Asset Enhancement 0 Comments

Condensation Issue in Building – Part 1

Unwanted condensation can cause the building damage and also affect human health. In Hong Kong, condensation is a common problem which almost every single owner has to deal with. Temperature difference and high humidity are the main causes lead to condensation occurs.

Condensation is created when warm moist air begins to cool down and the moisture is released. This moisture then settles on cold surfaces making them damp. This can happen quickly when warm moisture in the air connects with cold air or surfaces, such as having a shower and the steam from the shower hits the cold window or mirror making it wet to touch, this is condensation.

Source: https://www.falkirk.gov.uk/services/homes-property/council-housing/repairs-maintenance/docs/condensation/Condensation%20in%20your%20home.pdf?v=201910291603#:~:text=Condensation%20is%20created%20when%20warm,and%20the%20moisture%20is%20released.&text=This%20can%20happen%20quickly%20when,to%20touch%2C%20this%20is%20condensation.

Information from Hong Kong Observatory

March and April are milder although there are occasional spells of high humidity. Fog and drizzle can be particularly troublesome on high ground which is exposed to the southeast, and air traffic and ferry services are occasionally disrupted because of reduced visibility. May to August are hot and humid with occasional showers and thunderstorms, particularly during the mornings. Afternoon temperatures often exceed 31 Degree C whereas at night, temperatures generally remain around 26 Degree C with high humidity. There is usually a fine dry spell in July which may possibly last for one to two weeks, or for even longer in some years.

Source: https://www.hko.gov.hk/en/cis/climahk.htm

 

On average, May is the most humid.

On average, December is the least humid month.

The average annual percentage of humidity is: 77.0%

Source: https://weather-and-climate.com/average-monthly-Humidity-perc,Hong-Kong,Hong-Kong

Due to such high temperature and high humidity environment in Hong Kong, condensation will be easily occurs if lack of consideration in daily operation and usage of room. GBE has deal with many condensation cases caused by lack of communication in design stage and also in wrong material selection. With an detailed study and planning before design stage which can help in material selection and insulation. Also, the heat source from outside the unit or building will be needed to consider through out the design process.

Negative pressure in building which may cause a big effect of condensation as the hot air from outside collide with the cold air within the building. Many people deal with condensation problem with balancing the temperature and humidity difference between indoor air with outdoor air by ventilation. However, such measure is not practical when outside air is in high humidity which the ventilation system is not sufficient for get away the moisture within the area as the high humidity air will get through the window to indoor by negative pressure.

Source: https://basc.pnnl.gov/sites/default/files/images/HVAC515_whlbldgvent4_DS_1-10-13.jpg

The above image show that the exhaust-only ventilation only system may cause negative pressure which can easily made the outdoor air to the building or unit. In below example, a cold storage with 24 hours A/C control store room which was found with condensation problem with hot air getting through from outdoor air by negative pressure. The owner has installed a few dehumidifiers which were not sufficient to get rid of the moisture as the hot air from outdoor is non-stoppable. In such case, the high cost in electricity usage and also high maintenance cost may affect the owner in daily operation. GBE has studied and apply the insulation to stop the hot air to get in from the electrical cable duct and also can save the cost for running the dehumidifiers and prevent the rusting effect at the electrical cable duct. 

By John Lam Asset Enhancement • Building Technology • Uncategorized • • 0 Comments

Part 1 : Coating materials for Aluminium cladding – Non-Combustibility

From natural anodisation technique to PVF2 coating technique , the aluminium finishing coating has undergone a lot of revolutionary advancement. In recent years, there came with the discussion about “Self-cleaning” of the aluminium coating surface. This is about the coating materials which gives effect to flush its’ surface every time in raining. “Self-cleaning” is indeed a merchants’ name . The behind sciences are varying from among different manufacturer.I have conducted some comparison among some cladding’s surfaces being applied to different “treatment” allegedly claim the self-cleaning properties.  In my small research , some coatings are sheet- applied on the surface of anodised aluminium cladding. Unfortunately, my research (limited online data searching) cannot conclude sheeting-applied one was made up compilable to the Section E clause 10.1 of FS code or as per the BS476 -part 4. Well, many peers have messed up the concept of BS476 – PART 6 / PART 7 which is about spread of fire to BS476 – part 4 which is non-combustibility .

 

There are some testing to confirm “non-combustibility”. The FS code of Hong Kong does a job to cite a reference table E1 to facilitate the conversion between BS and European standard . There are many building in Hong Kong are cladded with aluminium-panel externally , but the lack of attention is paid to its “non-combustibility” requirement. Example like “self-cleaning” sheet lining or coating or spray-paint applied materials and even the fire – ratardard which are applied on external architectural features. The add-on materials on top of the aluminium are sometimes commercially attractive in term of ease of application and its price but to the sacrifice of fire safety.

Fire accident in Grefell Tower, London

Photo : Wing On building in Sheung Wan was reported to have cladded with non-combustible cladding. Source from ejinsight on the pulse ( http://www.ejinsight.com)

In my next blog , I shall explain in details the “self-cleaning” being applied in aluminium cladding.