MrKen Cosmo HVLS High Volume Low Speed 3m Eco BLDC Ceiling Fan – New 2020!
Whilst HVLS ceiling fans have been around for 10 years or so the low energy brushless DC (BLDC) versions of them are relatively recent. These bring all the benefits of moving a huge amount of air for a very low energy use. They are easy to install and considerably cheaper to operate with even quicker paybacks.
The MrKen Cosmo was launched in Thailand in July 2019 and has an amazing airflow of 92,000 m3/h – that is equivalent to 10 regular ceiling fans! It has already proved a big hit there due to its high-performance, light-weight, low-energy consumption, ease-of-installation and most important of all it is great value. It’s low purchase price is less than half of the competition which coupled with it’s lower installation and running costs make it unbeatable.
Features & Specifications:
- Motor finish – Steel plate
- Blade finish – Black or aluminium
- Blade material – Aluminium alloy
- No of blades – 6
- Total weight – 23 kg no support wires necessary, no scissor lift needed.
- Blade speed – 45 – 85 rpm
- Max airflow – 54,000 cfm = 92,000 m3/h
- Floor area covered – 400 m2
- Max power consumption – 157 watts
- Max power efficiency – 1235 cfm/w at slowest speed
- Motor Type – BLDC
- Power Supply – 240v, 50 Hz
- Gearbox – Not needed as direct drive
- Control – 6 speed remote control
- Zoning possible – Yes
- Mounting height blade to floor – 4 to 5 m
- Total drop – 114 cm from ceiling to blade
- Drop rod – 1 m included (longer drop rods available to order)
- Warranty – 10 years on motor
In stock in the UK Dec 2019, available now to pre-order.
High Volume Low Speed HVLS Low-Energy Eco Ceiling Fans
High Volume Low Speed (HVLS) ceiling fans are fans that have narrow helicopter type blades that range from 2.5m to 8m rotating slowly at 40-90 rpm to cool down and save energy for large buildings. They are very quiet compared to the propeller type of fans but move vast quantities of air for an incredibly low power consumption. They deliver two big benefits that directly translate into bottom-line financial energy savings all the year round:
- Wind chill effect – Evaporating sweat from the skin cools around 4 °C NB: this is not possible in 100% humidity conditions.
- Drawing in cool air – At night and early morning cool air can be drawn in through any windows displacing trapped heat and cooling down the solid mass of the premises by 8-10 °C which can then act as a heat sink during the day when it gets hot in the afternoon.
- Reduce AC Costs – If humidity and night temperatures are high then AC is needed. However the energy costs of AC can be drastically reduced as the temperature set point can be raised 5 °C for the same cooling effect which can save as much as 45% on AC energy bills.
Winter Heat Saving – In the winter months the hot air is not where it is needed. It is trapped at the top of the room and not down at the floor level. Often the heater is also at roof level meaning that the heat doesn’t make it down to floor level other than by slow convection. Hot air always rises and forms into semi-stable stratified layers of different temperatures. This leads to not only higher heat losses (as heat loss is proportional to the temperature difference with the outside) but cooler temperatures for staff at the floor level. An HVLS fan will break up these layers and move the hot air from the top back down to the floor level. Thus the heating is being used effectively and not wasted which can save up to 45% on heating costs. The fans can often pay for themselves – in under 6 months.
Air conditioning systems are extremely inefficient and very expensive to operate in large open spaces. Standard small ceiling fans hardly have any cooling effect in large facilities with high ceilings. Floor fans are very noisy, present a safety hazard, and occupy valuable floor space.
How do HVLS Fans Work?
The principle behind HVLS fans is to move large volumes of air using large diameter fan blades moving at a slow rotational speed breaking up the stratified air layers. The slow speed the fan makes it far more efficient at converting energy into laminar airflow instead of turbulent airflow and drag that occurs at higher speeds which ends up generating unwanted heat. A large bladed slow moving ceiling fan move more air than small high speed ceiling fans, typically 5-10 times as much, with an equivalent cooling effect. No other cooling system is as energy efficient as one using HVLS fans. In fact, studies have shown that businesses can lower or even eliminate the use of expensive air conditioning systems altogether with an optimized HVLS ceiling fan solution. Some HVLS vendors offer 3D thermodynamic modelling of their customers’ rooms which prove the efficacy of HVLS fans as highly cost-effective air cooling systems. This is considered overkill especially for low-energy DC HVLS fans since if the simple design rules are followed for coverage the operation will be effective.
AC vs DC HVLS Ceiling Fans
Just as with the smaller ceiling fans HVLS fans can be categorised into the AC and DC categories. The same benefits of DC DC vs AC ceiling fans apply – a much lower energy consumption typically 150w and 70% less energy like-for-like, better controllability with 6 speed settings and importantly a far lower cost of installation. This is because they are far more efficient motors. They are smaller, lighter and easier to lift in place using just a ladder – no need to rent cherry pickers. Also they have no special high tension guide wires, no expensive 3-phase voltage or high powered wiring is needed making them much simpler and quicker to install. DC motors are also direct drive and brushless meaning that no large heavy expensive gearbox is needed, no stepped power supply for startup, no overheating issues etc. The diagram to the right depicts a typical AC HVLS fan with a large inefficient motor and heavy gearbox.
HVLS Ceiling Fan Applications
The range of applications for HVLS fans is huge with almost any large room, hall or building a candidate for substantial operational savings. Putting conventional ceiling fans in these rooms is simply a waste of time and money since the volumes of air that need to be moved are so big as well as the height of the ceiling. The lack of knowledge about this can be seen in many retail “sheds” who have wasted money on “cheap” ceiling fans that do nothing but waste energy!
Applications where HVLS fans have been successfully deployed include:
- Warehouses and distribution centres
- Vehicle repair workshops & showrooms
- Airports, aircraft hangars and maintenance facilities
- Agricultural & farm – barns, dairy, poultry, pigs and equestrian
- Gymnasiums and sports halls
- Shopping centres and large retail stores
- Restaurants and food courts
- Manufacturing, production & assembly plants
- Industrial buildings
- Drying and curing processes
- Paper and cardboard manufacturing plants
- Document stores and warehouses
- Schools and hospitals
- Printing plants
- Fresh food & produce storage and packing sheds
- Museums and exhibition venues
- Transportation stations
- Churches, mosques and places of worship
HVLS Explainer Videos
These videos from our more expensive competitors explain how HVLS fans work at removing stratification.
Hunter Fan Industrial – Hunter entered into the HVLS market 4 years ago. This video from them explains temperature stratification.
2. Macro Air – Make some good fans at the large end 5-7m but their power consumption are nowhere as good as the Cosmo at the 3m size.
3. Macro Air – Computer model explains how the cool air is moved around.
Entrematic – Air movement shown with smoke.
Thermodynamics – How Heat Behaves
In physical chemistry terms heat energy should be viewed like matter, it has a size, body and content to it known technically by chemical engineers as enthalpy and when applied to gases can involve some fairly challenging mathematics! It is important to remember this when considering the best way to cool a space since that heat energy needs to be moved or removed from a room just like you would water from a leaking boat. If it is not removed then the room will simply get even hotter the following day. Hard solids such as concrete and brick are like batteries – they store this energy and give it off as heat until it is forced out by a sufficient heat difference with cool air. This heat difference can be created by either air-conditioned cooler air or by cool air taken from a cooler time of the day such as night time.
Once cooled a solid mass then acts as a heat sink until it is fully warmed up and cannot take any more. This is why buildings with very thick walls like castles stay cool even in heatwaves due to the huge capacity to soak up heat like a sponge soaking up water. Running a ceiling fan overnight with open windows will draw in cool air that will remove the trapped heat from the air and in turn the solid mass of the building making it cool and a heat sink for the start of the next hot day. This is easily done at the fraction of the running costs of air conditioning.