RAB Specialist Engineers present RABScreens

Where can I use a RABΞScreen BHA or BHC air intake filter screen?

RABΞScreens

RABΞScreen Protection stops debris before it costs you time, energy & money

Where can I use a RABΞScreen BHA or BHC air intake filter screen?

Anywhere that you have air movement. It does not matter what shape or size of opening we can design an air intake screen to suit every application. Dry air coolers, chillers, air handling units, condensers, cooling towers, intake louvres and air intakes of any design.

BHA – single layer of black, high abrasion polymer coated, polyester mesh. Black Pvc Coated High Abrasion Media is a 9x9 1000 Denier Multi Polymer Coated Polyester Mesh. The air flow resistance of a clean BHA air intake screen single layer is as follows:

0.50m/s               1.25pa
2.03m/s               8.75pa
3.05m/s               17.00pa

BHC – single layer black huckaback woven polypropylene. Black Polypropylene HoneyComb Weave is  a three Dimensional Polypropylene Honey Comb Weave which has a low air flow resistance whilst the electrostatic charge attracts  airborne debris. 

It can also be supplied in multiple layers of media to improve particle capture of 3 micron particles to 93%.  The air flow resistance of a clean BHC air intake screen single layer is as follows:

0.50m/s             1.25pa
2.03m/s             12.45pa
3.05m/s             22.42pa

Where would you use BHA or BHC?

The BHA air intake filters can only be used in a single layer  but it is a high abrasion filter and is perfect for the majority of applications where seed, pollen, leaves and insects are an issue. 

The BHC air intake screen is for use where fine particulate is a problem and a multiple layer filtration solution is required.  Ideal for fine cement, flour,  copier ink and other extra fine particulate.

Air Intake Filter Screens Prevent® and solve air intake problems

Permatron manufactures some of the world's leading air filters which are used to protect expensive HVAC equipment by stopping debris at air intakes - before it has a chance to enter the system.

Today more than ever before, mechanical, maintenance and process engineers are being challenged to provide effective solutions that help to optimise environmental air quality and process cooling efficiency, while reducing downtime and maintenance cost.

Regardless of the technology used to process incoming fresh air, the challenge has always been keeping cooling towers and other HVAC systems clean. When fresh air is drawn from the outside into HVAC systems, it brings along with it a wide range of airborne debris that can impact air quality and quickly clog the system. A clogged HVAC system ultimately leads to downtime for cleaning and maintenance.

In facilities that rely upon process cooling for robotic assembly, injection moulding or other production applications, downtime due to HVAC system fouling is particularly costly because of lost productivity.

Air intake problems are usually seasonal in nature. The times of year that represent the greatest maintenance challenge are spring, summer and autumn. Depending upon the season and region of the country, different environmental factors come into play.

In the spring, nesting birds are frequently problematic (especially in cooling towers). In areas where spruce trees exist, you can count on seed being a problem during the summer.

In wetland regions, insects are frequently problematic during spring and summer and in rural farming areas, leaves, pollen and crop harvest debris can be problematic during the summer and autumn.

Maintaining good air and water ecology are important elements in managing healthy and efficient HVAC systems. However, until recently, most businesses and institutions could do little to improve the quality of the air before it entered their systems. Hence entry of airborne debris places greater demand on the HVAC maintenance process.

Unlike traditional internal filter banks used in air handling units, air intake filters are installed on HVAC systems at the point where fresh air enters into the system thus filtering out debris before it can become a problem.

Air intake filters can also be installed on cooling towers, air-cooled chillers and condenser units or any fresh air intake opening. Air intake filtration is specifically designed to stop spruce seed, pollen, leaves, insects, birds, paper, construction debris and other airborne matter from being drawn into air intake openings.

Originally published by Permatron Chicago - Filtration Solutions since 1957

Air Intake Screens: The problem with free cooling

Air Intake Screens: The problem with free cooling: Is that it relies upon an efficient transmission of air through the fin coils to allow the fans to work at maximum efficiency with the lowes...

Small investments, huge savings

The Health Estate Journal recently ran an article under the heading "Small investments, huge savings". 

It states that one of the key conclusions from the IHEEM Healthcare Estates 2014 conference was that basic energy efficiency measures could "shave millions of pounds from NHS estates' running costs", and that hospitals and other healthcare buildings face both "an air conditioning legal crisis", and a growing threat from outdoor air pollution.   

The whole article is very much worth a read, but one of the key statements is that there is plenty of "low hanging fruit" that any hospital can use to quickly, and cheaply improve energy efficiency. 

This last statement is so very true. 

Hospitals are a 24/7 operation and have a significant need for cooling which can be found at the heart of most HVAC systems.  

In a recent example we surveyed two separate cooling systems at the same facility comprising 1 x Alfa Laval Fin coil unit SCAG-8-5 and 4 x Carrier 09GHCA-178. 
 
The annual energy consumption for these cooling systems totalled 1,618,000 kWh which costs the trust just over £194K per annum to run. 

As you can see from the images below the horizontal coil faces were dirty with compacted dust, seed, pollen and other debris drawn into the fins. 

In a USA study by Pacific Gas and Electric they identified that 1mm of debris on a coil fin would cause a 21% drop in efficiency and increase energy consumption by as much as 30%.    

“When a condenser is dirty or unable to reject heat or energy, heat increases both the temperature and pressure of the refrigerant liquid line. The higher total energy, increases the flash gas that decreases system efficiency and capacity” http://www.refrigtech.com/Knowledge_Center/Knowledge_Characteristics_Evaporators.pdf  

That is why this forward thinking trust contacted RABSE distributor Advantiv to solve the problem of coil clogging and reduce the cost of running their plant. 

By installing an air intake filter screen to protect the coil faces, contamination will be significantly reduced as the cooling season progresses. 

The air intake screen is manufactured using a polyester core and polypropylene overlay which, during air movement, creates a static charge. This electrostatic charge easily captures the airborne particulate to PreVent® it getting through to the fins. 

No airflow, no electrostatic charge and this enables maintenance personnel to easily clean the air intake screens using a vacuum cleaner, hose or brush.  

By comparing with similar sites we would expect to see a minimum 10% reduction in running cost as the condenser is kept clean and efficiently rejects heat. 

The air intake filter screens were secured to the coil support steelwork using marine grade, nylon drop tab fastenings. In the event that access to the fins is required the screens can be easily removed and replaced.

With an air resistance of only 17 pascals at 3.05m3/s this highly effective external filter will continue to protect the coils for at least 10 years and produce an ROI of less than 12 months. 

That leaves the trust with savings of at least £175K over the next 9 years and why we are proud to be saving money for the NHS.

Richard Betts

Managing Director – RAB Specialist Engineers Limited

www.airintakescreen.co.uk

01635 248633

richard@rabse.com

Experts. Are we just experienced or are we experts?

Experts. Are we just experienced or are we experts?

I saw this recent comment from a multi-trade specialist who are able to offer a range of services to the building services market.

Their comment says

"Contact our team of experts today and book your free"..............

I am always concerned when someone offers a free anything because invariably this WILL end up costing money because someone always ends up paying for it. 

If you are offering to survey a project that requires the installation of anything to anything then how can you realistically cost the job without seeing it? Unless of course you are working to detailed drawings. 

One of my ex-employees (Technical Director) once saw two water tanks. Unfortunately he only charged the customer for one, so even that doesn't always work.  

Anyway let's get back to experts. 

The word “expert” is formed from the conjunction of two roots which, phonetically, can be represented as “x” and “spurt”. Everyone knows that “X” is an unknown quantity, and that a “spurt” is what one gets from squeezing a drop of water. Therefore, an expert is an unknown drip under pressure.  

Definition: Expert from an article by Jerry Cates , first published on 24 August 2011

As Jerry says the above definition although amusing is not entirely correct.

Another definition from Brainy Quote suggests

Taught by use, practice, or experience, experienced; having facility of operation or performance from practice; knowing and ready from much practice; clever; skilful; as, an expert surgeon; expert in chess or archery.

However if you look at Wikipedia then:

"In line with the socially constructed view of expertise, expertise can also be understood as a form of power; that is, experts have the ability to influence others as a result of their defined social status. By a similar token, a fear of experts can arise from fear of an intellectual elite's power". 

We all seek advice all of the time because let’s face it that is the only way to learn.

If you are selling a safety product then it is easy to influence others based upon your level of experience. 

By carefully wording the proposal you can generate a fear factor.

Is that being an expert or commercial bullying?

At RAB we offer advice based upon our own experience and have even stated:

 "Technical expertise - the best people for the best service and the best finish"

But, are we truly experts or just very experienced at what we do?

That choice is one that we have to leave to our clients. 

Take a look at  www.rabse.com and www.airintakescreen.co.uk and make your own decision once you have spoken to one of our very experienced people.

And finally "An expert is a man who has made all the mistakes which can be made, in a narrow field". 

RAB Specialist Engineers Blog

RAB Specialist Engineers Blog

Another way to use an air intake filter screen

In the world of air intake screens there always seems to be another application you have never thought of before. 

Many companies already recognise the benefit of fitting an external filter to any piece of air movement equipment was it provides an additional protection layer for valuable plant.

That is why we have installed to dry air coolers, vertical and horizontal chillers, air compressors, refrigeration display cabinets, cooling towers, building main intake louvres and AHU air intakes as well as a host of other cooling  and air movement machinery.

In a recent survey of a paper factory we were expecting to find paper fines and the normal dust, seed and other airborne pollutants causing problems. 

However, the writer was asked to survey the inside of this paper processing plant and found that they had a big problem caused by the shreds generated on the production line.

Like most modern and highly automated factories this site had miles of conveyor systems all controlled by sophisticated electrical equipment mounted inside mild steel cabinets.

The control boards, switches and plc’s all generate heat and to maximise the space each cabinet was also fitted with its own air conditioner.

These integral AC units (see http://seifertsystems.com/us/engineering/ for an example) draw ambient air into the enclosure which is then cooled, circulated and discharged back into the factory.

This fan driven air supply also draws in the paper fines, which are then deposited inside the enclosure and clog up the evaporator coil.

Obviously clogged fins are something that we have discussed regularly (see http://www.airintakescreen.co.uk/cooling-coil-filters1 ) but paper dust and fines laying on electrical components is another risk we had never considered before. Maintenance requires regular shut down and cleaning in order to minimise the risk of fire.

That is why the electrical engineer was so excited when he saw the patented Permatron R1 Magnetic Filter which could be placed on the intake without drilling the cabinet. 

Acting as an external filter the BHC Honeycomb Media attracts the dust and paper fines and will keep the enclosure clean avoiding both evaporator failure and minimising the risk of fire.

During a recent failure the replacement cost was over £2,000.00 and also shut down the production line. 

Yet it could have been avoided with a simple £65.00 high flow, low resistance filter which can be removed and cleaned before refitting.It may not be superhero stuff but we were pleased that another problem has been solved by an air intake filter screen from RAB Specialist Engineers.