Hi Sustainable Development in Industrial Ventilation

Sustainable Development in Industrial Ventilation

The best route to sustainable development in industrial ventilation, dust extraction and waste extraction is through the design of the system. Moving air requires energy. Heating air requires energy. In both cases the potential to save energy over a prolonged period through good design exceeds that from other current efficiency developments. Key points of design include:

• The air volume
• Fan efficiency and motor control
• Heat recovery and air make-up
• Training and maintenance

Air volume:

The broad spectrum of industrial ventilation and process extraction requirements means that a simple solution to sustainable development is not possible as, for the most part, each system is a bespoke design for the specific application. However, optimizing the air volume in each design is without doubt one of the best. Why?

• Air volume is directly proportional to power
• 10% less air means 10% less energy

How is this achieved? Often through the design of the hood, the position relative to the emission source and how much that source is enclosed.

The hood designs in the diagram above represent concepts as there will often be limitations on how far this design philosophy can be followed. However, it is clear to see that the position of the hood relative to the emission source and changing to an enclosure hood design, where practicable, could reduce the required extraction air volume significantly.

Fan efficiency:

The range of fans used across the application of ventilation and process extraction systems being typically considered could have efficiency from 50% to 80%. The fan efficiency compares the input energy to the work done and has a significant impact on energy consumption, for example,

• 40,000 hours operation broadly equates to 5-years @ 24/7 or 10-years @ 16 hours 5 days per week.

Based on 25kW aerodynamic energy requirement and an energy cost of 10p/kWh

• A 50% efficiency fan would consume 50kW/h, at a cost of £200,000.00
• A 75% efficiency fan would consume 33.3kW/h, at a cost of £133,200.00

If this is compared to the stated difference in efficiency between IE3, IE2 and IE1 motors of around 1.5-2%, at these motor ratings, then notwithstanding the possibly increased capital cost of selecting a higher efficiency fan, the energy savings through the 40,000 hour life cycle are vastly more significant than the initial costs. For more information on these motor standards, look up "Premium efficiency" on Wikipedia.

Motor control:

A related aspect to consider is the motor control where further energy saving possibilities exists although often not through the widely promoted speed or frequency inverter control.

In the first instance it is necessary to appreciate the laws of physics which apply to fans once installed in a system, assuming there are no changes to the ducting design.

• A 10% increase in the fan speed increases the volumetric airflow by 10%; however it requires a 33% increase in electrical power.
• Conversely, a 10% reduction in the fan speed reduces the airflow by 10% and reduces the electrical power by 27%. Just 5% speed reduction reduces the power by 14% so the savings through speed optimization can be significant.

However, a fan only absorbs the power required to do the work so, reducing the speed by 10% through a change in the drive belts may provide the saving at a modest investment. And as the power and motor size increase the savings become disproportionately greater.

% fan speed	80%	90%	100%	110%
% motor load kW	51%	73%	100%	133%

Table of motor power change with fan speed change

Example

• 37kW motor installed
• 32kW absorbed by the fan
• Energy cost per annum, 24/7 operation, is £27,955 @ 10p/kWh.
• Energy cost per annum, 16/5 operation, is £13,312
• 10% speed reduction means absorbed power becomes 24kW
• Assuming new drive belts and labour costs £500 (renewed annually anyway)
• Then first year net saving at 24/7 operation is circa £7,000, then £7,500
• And first year saving at 16/5 operation is circa £3,000, then £3,500.

Of course this is only applicable to a fan with a drive belt system fitted. An inverter controller will do the same, although the installation would cost more and an older motor may not be suitable for frequency variation control.

It should be noted there are certain advantages in using an inverter over the simple drive belt option including:

• Applicable to all fans; direct drive or belt drive
• Further speed change adjustments are easily made
• Little loss in motor efficiency at reduced speeds, whereas reduced power at unchanged motor speeds may reduce the motor efficiency
• Fan speed reduction is limited to reducing the rated motor power by 50%, when other factors may come into play
• Applications with frequent start/stop cycles

In designing an extraction system, it is prudent and not untypical to err on the side of caution and allow for a modest increase in airflow and hence fan speed on completion of the installation, which would have an impact on the power required, and to select a motor one size above the bare minimum required. However, once installed and commissioned at the correct speed, the load on the motor may be some way below the motor duty, although only drawing the proportionate electrical current. Often a case is made for inverters based on the installed power rather than absorbed power of the fan motor. It is fairly simple for an electrical engineer to measure the running current of the motor compared to the motor rated full load current (FLC) to provide an indication of the energy being used.

Air input:

Exhausted air must be replenished either uncontrolled through egress into the building or controlled through an air make-up supply. Whenever the external temperature is below the required internal level, heat energy will also be required. Whether or not the air entering is controlled or not is often dependant on the building size and relative amount of extracted air. As an example, 70kW of heat energy would be required for a 20OC temperature rise in 10,000m3/h and with a 5p/kWh heat energy, could cost around £10,000 per annum on a 24/7 operation.

More sustainable approaches to air make-up include controlled introduction which reduces draughts and may, in some instances, lessen the heat load required. Re-using exhausted and filtered air will have an operational cost however often shows a payback within two to three years. Although less efficient than returning filtered air, heat exchangers may also enable the re-use of exhausted heat energy when filtering in impracticable. Sources of "free" heat should also be considered, compressors and hot process areas being valuable sources on occasion.

Once into operation the levels of training and maintenance can have an impact on wasted energy, environmental emissions or waste materials requiring landfill disposal.

The main objective under these headings is achieving optimum performance. By definition energy, emissions and waste are then controlled. It is a difficult position to reach and maintain. As ventilation and process extraction, (dust or waste), provide secondary or support roles to the principle production process all too often they get a lesser level of training and maintenance. Performance may decline gradually over time and often goes unnoticed with some examples including:

• Incorrect low compressed air pressure or cleaning control settings resulting in lower filter cleaning efficiency. This increases pressure drop and hence the absorbed motor power, and may reduce extraction efficiency.
• Incorrect high compressed air pressure resulting in "puffing"- dust passing through the filter bags due to over-cleaning which increases the carry-over emissions and reduces the life of the filter bags through fatigue during the cleaning process.
• Incorrect fan belt drive adjustment leading to a loss of fan speed which could lead to lost production through a build-up in the ducting or lower efficiency in the extraction and a reduction in the control measure. Complying with COSHH/LEV guidelines may help to identify this, however with 14 month intervals there is a risk of long term deficiency.
• Operators using equipment in an unintended manner is all too frequent and often goes unrecognised. When this situation occurs, performance as a control measure, emissions to atmosphere and an increase in energy consumption may easily result.

In conclusion, sustainable developments in industrial ventilation and process extraction applications are not only achievable but may be quite significant because they are based on good system understanding, design and use. Interestingly many recent developments in energy efficiency are over shadowed by the improvements which may be possible through design, equipment selection and an on-going user training and maintenance programme. It is clear that any low cost installation advantage may be far from the lowest overall cost and soon offset as running and service costs are included over a modest period of time. Also, when using and maintaining the system as intended, the safety and protection provided will be optimised.

How Nanotech Technology is incorporated with HVAC advances?

Industrial Nanotech imparts how innovations with nano materials can improve HVAC processes.

The insulation and air quality efficiency of HVAC systems has not changed much in the past 50 plus years. However, new advancements in nanotechnology-based insulation and anti-microbial materials offer advantages that provide the ability to insulate in less space, increase longevity of performance, improve weathering and moisture resistance and increase air quality – all with an objective of affordability and cost-effectiveness.

WHAT ARE NANO MATERIALS?

Nanotechnology is simply the manipulation of materials at a smaller scale than was previously available. By manipulating matter at the nano scale, materials have the ability to be built from the atomic level up, with much less waste. Science has also found that materials can take on different attributes when you manipulate them at this scale, such as silver taking on anti-microbial properties.

Nano materials is one of the fastest growing branches of nano science and within this falls nano coatings. Coatings are being invented that have the ability to provide attributes such as heat resistance, rust prevention, resistance to contagions and a variety of other surface protection qualities.

IMPROVING HVAC INSULATION USING NANO COATINGS

Insulating HVAC systems is paramount to reducing building energy consumption and related greenhouse gas emissions. For years we have been trained to think that you need thickness in order to insulate. However, just as cell phones and computers have shrunk and yet become more powerful over the years, so has insulation.

The newest form of insulation incorporates a nano material with very low thermal conductivity into a clear, water-based acrylic latex to provide a thin film coating that can be painted onto a variety of substrates, such as duct work, piping and boilers, to insulate effectively and consistently.

One benefit that a thin film thermal barrier provides is the ability to resist infiltration from moisture, dirt, dust and other contaminates that typically cause degradation of fibrous insulation's like fiberglass or rock wool. By using a nanotechnology-based coating for the insulation of critical HVAC system parts, overall replacement and maintenance costs can be reduced and the ability to insulate outdoor and rooftop equipment without the issues that come with rain, snow and other weather exposure is provided.

Thermal insulation and protective nano coatings have been shown to reduce energy costs by between 10 and 40 percent, depending upon the application, with a consistent insulation value throughout the five- to 10-year lifespan.

REDUCING CONTAGIONS USING NANO COATINGS

Indoor air quality is another area where nanotechnology can assist in reducing contagions that may infiltrate an HVAC system. Building health is an increasingly important topic as it directly relates to the health of the workers inside any facility. Some of the advances in nano coatings address issues with mold and fungi growth and corrosion prevention, as well as provide anti-microbial properties.

Infiltration of mold or fungi into an HVAC system contribute to an unhealthy building. When traditional fibrous insulation becomes moist, it can become a breeding ground for these types of contagions. Other contagions can come from infiltration of outdoor air due to rusting duct work or piping, which leaves unwanted openings into the system.

Nano coatings are able to provide resistance to mold and fungi growth, prevent corrosion, and some are anti-microbial and can be used internally on duct work to reduce unwanted contagions. One anti-microbial coating incorporating nano silicon dioxide was shown in hospital trials to reduce bacteria by up to 50 percent on surfaces treated with the coating.

THE CHALLENGES OF THIS NEW TECHNOLOGY

As with any new and advanced technology there are challenges to adoption. One of these is that often measurement standards put in place and written into building codes were made to measure an older technology and do not always have the ability to measure new technological advancements. Standards tend to be behind industry innovations.

A challenge concerning the use of nano coatings for insulation is that the make-up of the material used allows the reduction of heat conduction in a thin layer and standards used, such as the R-value (R standing for resistance to heat flow), weigh thickness heavily into their equation of effectiveness, meaning they can’t be used to accurately reflect the energy saving ability of new thin film insulators.

To overcome this challenge, other building standard tests that measure direct heat conduction in energy units, such as watts or btus (British Thermal Units), that show the reduction in thermal transmission without skewing the result by thickness need to be used.

Another challenge is the fear factor any type of new technology brings, and nanotechnology is no stranger to this. People fear that nano-sized particles may infiltrate their skin or otherwise be a danger. However, nano scale particles are not used, but rather nanotechnology is incorporated in another way into materials, so there should be no fear of any infiltration of tiny particles. In addition, companies in the field offer health and safety testing to allay fears.

THE ADVANTAGES OF CHANGE

While you should do your homework before deciding on adopting any new technology for HVAC efficiency, it definitely can pay off to see what innovations are available from nanotechnology-based materials. Nanotechnology has now come out of the lab and has been making a difference in industry for at least a decade. It can enable huge improvements in energy efficiency, reduced greenhouse gas emissions, and overall increased longevity, health and air quality of a heating and cooling system.

The earlier adopters of these advanced technologies are already experiencing the benefits of their willingness to change old ways of thinking. As with all new technology, this eventually promotes the needed change in standards – and in the not too distant future, we should see nanomaterials being incorporated into standards and specifications, and being increasingly used as a mainstream choice for efficient HVAC processes.

The design, construction & operation of sustainable buildings -"ASHRAE"

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OSHA Adds New Chapter On NOISE to Technical Manual

Being Informed is Being Prepared.

OSHA just added and published a new chapter addressing noise to the OSHA Technical Manual.

This new chapter provides technical information and guidance to help Compliance Safety and Health Officers (CSHOs) evaluate Noise hazards in the workplace. The content is based on currently available research publications, OSHA standards, and consensus standards.

Visit the Occupational Health & Safety Administration of law & regulations page of the United States Department Of Labor. Click here to visit OSHA website and access site documents & search list of OSHA standards. 

The New Noise Chapter is downloadable by clicking this link here.  You may also wish to download the OSHA inspection fact sheet by clicking here. View OSHA technical manual text & links by clicking here. 

Selective Recommend Documents made available to view &/or download below from OHSA site; 

View & Save The OSHA Field Technical Manual PDF below.
alternatively click here to download

You might also want to view or download  the copy of the OSHA Employers Rights And Responsibilities Handbook PDF.
Alternatively Click link here to download

This New Noise chapter provides technical information and guidance to help Compliance Safety and Health Officers (CSHOs) evaluate Noise hazards in the workplace.

The content is based on currently available research publications, OSHA standards, and consensus standards.

Click Here or Image To Download Noise Chapter

The chapter is divided into six main sections:

Introduction and background information about noise and noise regulations and an overview of noise controls.

• Worksite noise evaluations, including noise measurement equipment, noise evaluation procedures, and noise sampling.
• Investigative guidelines (including methods for planning the investigation) and outlines a strategy for conducting noise evaluations.
•  Noise hazard abatement and control, including engineering and administrative controls, hearing protection, noise conservation programs, cost comparisons between noise hazard abatement options, and case studies.
• References used to produce this chapter and resources for obtaining additional information.
• Appendices provide a glossary of terms, sample calculations, and expanded discussion of certain topics introduced in the chapter.