Frequently Asked Questions (FAQs)

What different types of filters are incorporated in our systems?

There are usually 4 types of air filters in RHT systems

1) Pre-Filter

2) Static Filter

3) HEPA Filter (Grade 13)

4) NCCO Reactor Filter

How much maintenance is required for the air filters?

This varies from air purifier to air purifier. Most air purifiers have two to four filters.

- Pre-Filters should be cleaned (by washing with soapy water every month). - We suggest that Static Filters should be changed every 3 months. - HEPA Filters should be changed every 12 months but it does depend on the level of pollution. - We advise that RHT's NCCO Filter should be changed every 3-5yrs.

How loud are our Air Treatment Systems?

The loudness of an air purifier (measured in decibels) depends on a few factors such as the model of air purifier, the fan operating speed, and personal noise tolerance.

Most air purifiers feature multiple cleaning speeds. Thus, if your air purifier is operating at its maximum cleaning speed, it will be louder than if it is operating at a lower speed. Keep mind, however, that noise is subjective and what might be intolerable to you might not be as loud to someone else.

RHT units have a range of between 30 and 58 dB noise level

I just received my new RHT unit but after I switched it on, there seemed to be a strange smell given off. Should I be concerned?

No, it will not affect your health, it’s a normal odour given off when the initial Catalytic Oxidation process starts within the NCCO reactor. This will disappear as the unit is used.

Does your ceiling type have remote control?

Yes, the operator can control the ceiling unit remotely. Also, there is a separate remote control for the resetting of the filter life after replacement. This remote control is only supplied to technical support engineers.

What does ACH stand for?

ACH stands for Air Changes per Hour. This indicates how frequently the air purifier filters or changes all of the air in a given space per hour. For example, an ACH rating of 6 means that all of the air in your room is thoroughly filtered six times per hour.

What does CFM stand for?

CFM stands for cubic feet per minute. This measurement can also represents how many cubic feet of air moves through the unit per minute and so is termed as Air Flow Volume. The higher the CFM, the better potential air purification results.

Keep in mind that CFM can be impacted by a variety of factors, including fan speeds, insulation, air flow in the room, furniture in the room, and the amount of pollutants in the air. However, there is an equation to help you determine an ideal CFM, which can provide help when deciding on air purifiers.

What does CADR stand for?

This acronym represents an important measurement for air purifiers. CADR stands for Clean Air Delivery Rate.

This measurement was developed by the Association of Home Appliance Manufacturers (AHAM).

It indicates the volume of filtered air delivered by an air purifier. It is given in three measurements - one for pollen, one for tobacco smoke, and one for dust.

The higher the CADR number, the faster the unit filters the air.

Is the CADR value a true reflection of the performance of an air purifying system?

Did you know that CADR only tests performance for no more than the 20 minutes of operation, and provides no basis to evaluate long-term performance of air purifiers. It cannot account for the performance decline of many air purifiers over a longer period of time.

CADR does not test the effectiveness of air purifiers in removing for harmful gases, chemicals, and odours. People who suffer from Multiple Chemical Sensitivity (MCS) should be aware of the relevance of CADR ratings.

What is the HEPA filter made of and how does it work?

HEPA filters are made of densely spaced glass fibre. Typically a washable pre-filter traps all larger particles and then the best HEPA filters remove at least 99.97% of all particles larger than 0.03 microns. Allergens such as pollen, pet dander, mould spores and dust get trapped in the dense fibres of the filter. Many HEPA air purifiers also contain a carbon filter to capture chemicals, odours and gases. Once the contaminated air is purified, a fan sends it back into the room as clean air. Please be aware that there is potential to saturate these filters, leading to secondary pollution.

Can NCCO technology remove smoke?

Yes, it is very effective at removing smoke

Can NCCO kill bacteria and viruses?

Yes, NCCO technology has proven to be effective in killing viruses and bacteria. Video

It has test certification for the following e.g.

Virus H3N2

Bacteria – Staph Albus

Fungi - Candida Albicans

What is AQI & IAQ?

Air Quality Index (AQI)

Is a system used to warn the public when the outside air pollution is dangerous.

Indoor Air Quality (IAQ)

Is the air quality within and around buildings and structures. IAQ is known to affect the health, comfort and well-being of building occupants.

Poor indoor air quality has been linked to sick building syndrome, reduced productivity and impaired learning in schools.

Do you have any scientific data on the improvement of air quality, specifically with formalin fumes?

Yes, RHT has scientific data to support its claims of pollution removal including following pollutants;

a) Formaldehyde

b) Ammonia

c) Ozone

d) Toluene

e) Acetone

f) Xylene

g) Benzene

h) Acetic Acid

Could you please advise as to which b-MOLA model should be used for differing room sizes, and give optimum Indoor Air Quality? (BM10, BM50, BM100)

Could you please advise as to which b-MOLA model should be used for differing room sizes, and give optimum Indoor Air Quality? (BM150, BM300)

What produces active oxygen in our air treatment systems?

Active Oxygen is generated by the AOG (Active Oxygen Generator) built into RHT/b-Mola air treatment systems.

What principle is used to generate this active oxygen?

High voltage difference is applied between two electrode plates and when air pass through the gap between the electrodes, it ionized and so generates active oxygen which contains highly reactive molecules that include oxygen atoms.

What type of active oxygen is generated in the NCCO system?

The active oxygen is generated by ionization of air contains the following mixture;

a) Oxygen

b) Oxygen radicals

c) +ve and –ve charged molecules

d) Ozone

e) Hydroxyl radicals

f) Hydroxyl ions

g) Hydrogen Peroxide

Please advise if different types of active oxygen are generated by the AOG in the NCCO system, other than ozone?

Active oxygen generated is a mixture of oxygen radicals, negatively and positively charged molecules, ozone, hydroxyl ions and Hydrogen peroxide. Not only ozone.

People normally are more concerned about ozone as it has the longest lifetime among all the active oxygen species generated. Also excessive amounts of ozone has a negative and dangerous harmful effect on the human body.

Doctors dealing with asthma might be nervous in using ozone generating air treatment systems because of the harmful effect of ozone. Are RHT/b-MOLA products safe for patients with asthma, and do you have data to support your claim?

NCCO technology is safe for all kinds of users, including asthma patients. There might be some misunderstanding about the active oxygen (or as explained before, where people normally have most concern about ozone). Any active oxygen produced is generated internally and within the system. It is not released externally into the air like other ionizing or ozone producing products in the market today.

Any excessive active oxygen generated inside our systems will be consumed internally and will not be released into the air.

All of our products has are compliant with CE, and where ozone emission is one of the parameters tested for compliance. Our CE report complies to IEC60335-2-65 where the ozone emission is required to be lower than 50ppb. The test is performed in a confined environment with our NCCO system being operated over a period of 24 hours. Ozone is measured at the air outlet and the concentration of ozone is required to be lower than 50ppb.

One of our staff who has allergic rhinitis has started to use one of our air treatment systems. She felt that her b-mola air purifier released warm air for the first 30 min – 1 hour after switching on for the first time. Sitting close to the air purifier, she also developed a cough and experienced some discomfort when breathing. However, after no more warm air was released, she felt fine and her breathing problems ceased.  Was the effect on breathing initially caused by the release of ozone when the unit was first switched on?

When the NCCO Reactor is used the first time, it will release some heat. Such warm air generation is stated in the Instruction Manual, and is a perfectly normal occurrence. This is a transient effect and the heating will no longer happen after further use of the air purifier.

What would you like to know



HSBC’s prestigious data centre is situated adjacent to a landfill area and the odour from it entered the building via the fresh air system causing employee distress and health concerns......