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Cleanroom HVAC Design

A cleanroom’s HVAC system is truly the most vital and complex component system of a cleanroom facility.  HVAC…an acronym for Heating, Ventilation, and Air Conditioning…generally describes the idea of providing indoor environmental comfort by creating and controlling indoor air quality (cleanliness, air changes per hour, temperature, humidity and pressure).

 

Here are some highlights that summarize how cleanroom HVAC systems are unique:

Cleanroom HVAC vs. Conventional HVAC

In addition to creating a comfortable environment…Cleanroom HVACs specifically focus on:

  1. Increased Air Supply
  2. Airflow Patterns
  3. High Efficiency Filters
  4. Room Pressurization
  5. Regulations & Cleanliness level guidelines
  6. Temperature & Humidity Control
  7. Accounting of processes taking place inside the cleanroom
  8.  Specialized Ventilation Duct Expertise

HVAC System vs. HVAC Unit

HVAC systems and their component HVAC air handling units (AHU) are sometimes confused. The air handler is simply the enclosure in which the air is heated, filtered, and cooled. It includes DX cooling coils, chilled water coils, electric heat or hot water heat coils and humidifiers. The HVAC system is, as its name spells out, the whole system, which includes the air handling unit, but also the duct work, the diffuser, the HEPA filters, the air return, and the control and monitoring system.

Choose/Design the appropriate system

The required cleanliness level of the cleanroom (ISO class) is the key driver of the HVAC design process…in addition to the required temperature, humidity, and pressure differential. These conditions are dictated by the processes taking place in the cleanroom and the required comfort of the personnel working inside the room.

Air Flow (CFM)

The most important bit of information needed to begin the Cleanroom HVAC design process  (by your cleanroom supplier/manufacturer) is:

How many air changes per hour is needed in your cleanroom in order to calculate the required air flow? (CFM: cubic feet per minute).

Though difficult to determine, the answer must take into account the following elements:

  • Cleanliness level (number of particles per cubic foot of air) the cleanroom must be kept within: often determined by the cleanroom class (ISO 5-6-7-8, GMP A-B-C, etc.)
  • Number of people working in the cleanroom
  • Size of the cleanroom and the number of rooms inside
  • Equipment, furniture, and supplies inside the cleanroom since they generate air particulates and contamination
  • Heat gain
  • Movement of people and material in and out of the cleanroom

Temperature and Humidity

The heat produced by both the users and the equipment must be compensated by the air conditioning. Therefore, it is important to know how many people will be working in the cleanroom, the equipment in place and the heat it generates (watt).

Pressure Differential

The HVAC system is responsible for creating pressure differentials to keep pressure cascades in between the divisions of the cleanroom and the outside of the cleanroom.  Most cleanrooms are held in positive pressure. This means that the air will flow out of the room instead of in, thus preventing unfiltered air or air particulates from entering the cleanroom.  When dealing with hazardous products however, the cleanroom must be held in negative pressure.

 

Read More – CEMag

Chillers & High Performance HVAC – A Viable Option

Building owners and managers of high-performance buildings have several viable HVAC options that span:

  • Rooftop Units
  • Variable Refrigerant Flow (VRF) Systems
  • Geothermal or Air-Source Heat Pumps …and
  • Chillers

Large commercial buildings and similar facilities have largely considered Chillers as their top choice HVAC system, but stiff competition from new technologies, such as VRF systems have gained prominence in recent years…often because they are considered being easier to install and maintain.


But Chiller manufacturers are quick to respond that chillers offer:

  1. Exceptional energy efficiency as well as greater design flexibility
  2. Better Comfort
  3. Lower Total Life-Cycle Costs

These factors and more…making chillers a well fitting top choice for high-performance buildings.

WHY CHOOSE CHILLERS?

Energy efficiency is a primary concern among owners & facilites managers of high-performance buildings.  In fact, ASHRAE Standard 90.1-2013 shows water-cooled centrifugal chillers with capacities of 400 ton or more to be more efficient than other mechanical cooling technology, including air-cooled chillers, rooftop units, and self-contained systems, said Christine Detz, senior product manager of centrifugal chillers, building technologies and solutions, Johnson Controls Inc.

“Water-cooled chillers can also be designed to function over a wide operating envelope, which means warmer chilled water temperatures and colder tower water can be used for greater energy savings,” said Detz. “Other types of chiller designs, such as air-cooled free-cooling chillers or variable-speed drive (VSD) chillers, can minimize compressor runtime, which helps to increase energy savings even more. In other words, chillers deliver efficiencies, capacities, and options that make them advantageous for buildings designed for exceptional performance — not just for energy savings but also for cost-effectiveness, sustainability, functionality, productivity, and other performance-related criteria.”

Since HVAC systems account for a significant portion of a building’s energy use, chillers can be critical components in improving a building’s overall efficiency, noted Mike Patterson, centrifugal chiller product manager, Trane.

“Chillers also have a low total cost of ownership, offering high-performance building owners cost savings over the lifetimes of the systems. ~ Mike Patterson – Trane

“Well-designed chillers work with HVAC systems to deliver the right temperatures, humidity levels, and ventilation for the space while also prioritizing low operating cost and energy efficiency and ensuring low sound levels and minimal environmental impact.”

Read More – ACHRNews

HVAC Maintenance and the Art of Keeping Cleanrooms Clean

Keeping contamination at or below predetermined acceptable levels is a fundamental requirement of cleanroom maintenance.  Even the tiniest random dust particle is considered a legitimate contaminant.

HVAC systems are by definition a critical component system of any cleanroom environment because they are designed to move air from one area to another with the goal of attaining climate control. This process poses many unique challenges to maintaining air quality.  Part of the HVAC system intricacy is that it’s also comprised of multiple other systems that need to be maintained in order to achieve cleanroom high performance standards safely and effectively.


Here a some steps toward keeping your HVAC system clean:

  • Change Filters Regularly – Cleanrooms contain multiple filtering systems… pre-filters, standard filters, and high efficiency filters…Combined, they virtually guarantee that airflow remains free of contaminants down to sizes under .03 microns.  An adequate filter maintenance program shuld schedule filter cleaning at minimum of four to eight week cycles.
  • Clean Coils Regularly – Clean coils keep the system operating at high efficiency levels as well as mitigating bacterial growth within the system. Clean regularly at planned system shutdown intervals and treat with EPA-registered mold and mildew inhibitors.  Properly maintained coils can play a key role in managing critical humidity levels.
  • Clean Blowers Regularly – Blowers in air handler units (AHU) can be magnets for dirt and debris. Make sure to properly visually inspect and clean these often overlooked, yet critical, components of the HVAC system.
  • Clean Ductwork Routinely-  Often overlooked in normal commercial HVAC systems…but in the case of cleanrooms, duct cleanliness is vital. Inspect and clean all ductwork  when  routine filter changes are performed.
  • Clean Other Major HVAC Components – Cooling towers and boilers, for example. As with all above prescriptions, it helps to maintain peak system efficiency and performance.

 

Of course, all the above should be performed by thoroughly trained and highly qualified technicians. But when done correctly and routinely, the process yields several benefits.

Key Benefits of HVAC Maintenance:

  1. For cleanroom management, it’s a necessity and not an option.
  2. A clean HVAC system reduces energy costs, because it doesn’t need to work as hard to keep up as it would if the system was dirty or filled with debris and other contaminants.
  3. HVAC system potential breakdown or need repair is greatly reduced and controlled. Scheduled and properly performed HVAC system maintenance is much less time-consuming much less expensive than shutting down the system for larger repairs or even replacements.

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See Also

 

HVAC Emergency Preparedness

Emergency-preparedness plans are created by many businesses and organizations with the main objective of keeping the organization itself functioning, but few factor in a plan for dealing with HVAC equipment failure. Disasters like floods, hurricanes, tornadoes, fires and earthquakes can grind business operations to screeching half for a period of a few hours to days, weeks or even months.  Having a plan in place will minimize the HVAC systems downtime, and ease the interruption of the occupants operations.

Here are four steps to create and implement an HVAC Emergency Preparedness Plan for your facility or business:

Existing HVAC Systems Review –  identify critical equipment that if failed, would have greatest disruptive impact on operations overall.  In terms of facility’s HVAC needs, understanding all  heating and cooling load requirements for each area of the facility…particularly,  identifying the availability of power, amperage, and electrical connections.


Risk Assessment – Prepare a risk assessment for each area of the facility….creating an order of priority for each system(s) that would need to be restored with temporary cooling. An important consideration in this process is whether one central system serves the complete facility versus multiple systems serving specific areas of the facility. This risk assessment priority order should be a joint effort between the HVAC contractor and the facility owner.

Plan Creation – Determine a recommended temporary equipment solution set to meet the facilities emergency load requirements.  Temporary equipment should be located as close as possible to the current equipment. Now, you’re in position to prepare a cost estimate for the temporary rental equipment including set-up, implementation, and ongoing temporary operating costs.

Implement and Sustain – Regularly update this newly created HVAC Emergency Preparedness Plan so that implementation will be a step by step process should a catastrophe actually occur. Ensure that all documents, such as rental agreements, are in place and that any building modifications are made.  Create a preset arrangement with the temporary equipment vendor with agreed upon fees and strategy. Train personnel on this new Preparedness Pland and have a flow chart with responsibilities and phone contact list.

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Still More

 

Temporary Cooling During HVAC Upgrades

Like any other mechanically oriented system and equipment…commercial HVAC systems eventually need to be replaced. Smart facilities managers that follow best maintenance practices can slow down deterioration and maximize useful life…replacement is inevitable.

Consequently, major operations disruptions are unavoidable and need to be planned for by maintenance and engineering managers since substantial areas of the facility could go without air conditioning for time periods ranging from days to months.  The potential impact on building occupants is obvious.  Temporarily relocating operations to other areas is one alternative, but most won’t have that flexibility.

Fortunately, the marketplace has provided multiple options for temporary cooling solutions.  They range from small, self-contained units for cooling a moderate sized room, often called “spot cooling”…to massive trailer-mounted units capable of cooling entire buildings.

In either scenario, advanced planing by managers is required to achieve an effective temporary cooling plan. They must:

  1. Size the units to meet the cooling load…
  2. Understand power requirements for the temporary unit and make power available, and…
  3. Lock in purchase or rental contracts well in advance of time needed for deployment.

Waiting for a crisis to occur that will ultimately require the use of a portable unit, can only lead to project delays or disruption of services.

Advanced Needs Assessment dictates that Managers must start the planning process by identifying areas served by the system being upgraded.  Next, they will have to determine the amount of cooling capacity these areas need.  Managers need to size temporary units so they have adequate capacity to properly cool and dehumidify the area the units served.

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5 Portable Air Conditioner Inventions You Must See

Everyone likes a list of cool items that basically cut to the chase on a heavy duty amount of research that offers a highly practical bottom line for someone in that particular marketplace.  Well, it’s still Summer and it’s still Hot outside, so here’s some nifty ideas on cooling down on a small scale.

  • Wynd – a smart air purifier that monitors and cleans the air in your home. This system is so portable…you can bring it everywhere you go.
  • Zero Breeze – a portable air conditioner that also includes some practical gadgets. It comes complete with a Bluetooth speaker,a night light,and can charge your smartphone 3 time over,whether it’s a Samsung or the latest iPhone 7.
  • Amazing Air Conditioner – a personal and affordable air conditioner that costs only 3 cents to operate.  It uses less energy than a traditional air conditioners or electric fans.  Frankly you can do this yourself…just use a block of ice, a bucket and fan…and you’ll get a homemade air conditioner.  But this version is more stylish than a DIY version…and again it costs less to operate.
  • Ambi Climate – a small connected device that can take control of any existing infrared remote controlled air conditioner smart.  After installing this technological marvel…you can control it with your smartphone.  This gadget helps you monitor the temperature inside and outside your home. Key Features: 1) it uses your existing A/C …and 2) It’s compatible with any infrared remote-controlled ac unit.
    • Automatic air conditioner control
    • Learns and remembers your thermal comfort preferences.
    • Turns on your AC as you’re heading home
    • Syncs your ac with your iPhone or android device
    • No tools or expertise needed for setup
    • Energy-saving tips and ac maintenance notifications.
    • Saves up to 30% on air conditioning energy usage.
  • Noria – a window air conditioner that’s extremely easy to install and beautifully designed. You can control Noria using your iPhone or android device.

Read & Watch More

Commercial Buildings – 3 Heat Beating Tips

Summer’s here…that means greater required energy consumption to cool the outside air as it enters a building, resulting in higher costs.  The status quo of most commercial buildings is that indoor air is replaced with outside air every one to two hours to prevent high concentrations of indoor pollutants.  Sounds great, but it’s also costly because requires a high volume of outdoor air that must be cooled to maintain comfortable temperatures and humidity inside the building during the summer months.

What about cleaning and recycling the indoor air instead of constantly replacing it with outside air?


Here are some Summer tips for facilities managers to consider when preparing their buildings to beat the heat:

New Technology – Outside the HVAC Box

Using less outside air for building ventilation:

  1. Boosts Energy Efficiency
  2. Save Costs
  3. Maintain Air Quality…keeping occupants comfortable?

Cleaning and recycling the indoor air instead of constantly replacing it with outside air has 4 more benefits:

  1. Complies with the American Society of Heating, Refrigeration and Air-Conditioning Engineers (ASHRAE) Standard 62.1 Indoor Air Quality Procedure (IAQP).
  2. This technology decreases the outside air intake required to ventilate a building by 60 to 80 per cent.
  3. Reduces peak HVAC capacity, resulting in 20 to 30 per cent energy savings and up to 40 per cent lower utility demand charges.
  4. Extends air filter lifespan…reducing water consumption, and will help postpone HVAC equipment replacement. Moreover, with this technology, buildings can invest in lower-capacity and less expensive HVAC systems, and benefit from decreased maintenance costs.

Prioritize Indoor Air Quality

Improved indoor air quality in buildings can help boost cognitive performance by 101 per cent, which translates into $6,500 per year in additional productivity per employee. ~ Harvard T.H. Chan School of Public Health

The productivity and health benefits for building occupants is astounding…

The Internet of Things in Action

This new HVAC technology describe above also permits increased visibility through IoT capabilities that provide 24/7 monitoring and management of a building’s indoor air quality, temperature, and humidity. These real-time insights into air quality and comfort allow for more proactive management of buildings to help reduce energy costs.

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Rooftop HVAC Unit Maintenance 101

Being proactive with regular routine maintenance of rooftop HVAC units is only a smart idea.  Otherwise…dealing with every little performance issue as they arise can not only be costly…with respect to replacement parts and labor, as well as the excess energy costs while the equipment is underperforming.

Routine maintenance on a scheduled basis helps to identify problems BEFORE they occur…so they can be corrected to avoid the cost of major repairs later.  These basic steps are a good guideline to follow when performing scheduled maintenance on rooftop units.

  1. Power Check – After making sure the unit has power…look for any service lights or faults codes as a clue to any potential problems.  Usually powering down (turning off) the main unit, then turning it back on will reset the unit control board…potentially losing any fault codes displayed.  Fault codes may be displayed on the unit itself (viewable through a small sight-glass near the electrical service panel) or on the thermostat.  Adjust the temperature set-point on the thermostat and listen for a clicking noise, indicating that the thermostat relays are engaging.
  2. Visual Check – Look for oily or greasy areas on the unit as potential signals of a refrigerant leak.  Closely inspect the condenser and evaporator coils…seeing if they need to be cleaned. Ice on the evaporator may mean a low-refrigerant charge or “low airflow” due to a dirty or too restrictive air filter.
  3. Electrical Connections Tight? – After a good visual inspection for warning signs of any service problems that need addressed…turn off the power to the unit and begin the maintenance process by tightening all electrical connections. Many failures on units are due to loose wiring. Be careful when tightening the electrical connections on the compressor: if they appear damaged or overheated in any way, the terminal connections may be compromised. If the capacitors appear to be deformed (swelled or leaking) consider replacing them, as they may be nearing the end of their life-cycle.

See the next three (3) steps: Read More

Improving Indoor Air Quality with Window Automation

How indoor air quality (IAQ) impacts human health and everyday comfort has grown considerably in importance in recent years…causing changes in management techniques on ventilation of commercial building environments.

Dangers of mold growth are created daily through normal activities like cooking, consuming food and washing…leading to negative effects on indoor air quality (IAQ) from increased humidity introduction of pungent air particles that foster an environment conducive to mold growth.

Improving Indoor Air Quality with Window Automation

…poor IAQ can cause a broad variety of health impacts which while mild, can still significant diminish the comfort of work efficiency of building occupants. ~ Sophi MacMilan – Environmental Scientist & CEO of the Vinyl Council of Australia

Potential health impacts range from general symptoms such as headaches and fatigue to more serious ailments including respiratory issues and allergic reactions.  Such problems can cause major dilemmas for stakeholders in buildings such as office complexes, given that employers are required by law to provide safe workplace environments to their staff.

The obvious solution to improving IAQ is effective ventilation that provides consistent and unimpeded airflow through a given indoor environment, replacing stale air and flushing out unwanted particulate matter.

MacMilan notes that ventilation during time frames as brief as one to five minutes can be sufficient to completely replace all of the indoor air contained by a room without causing thermal mass walls to lose temperature, meaning that warmth can be retained during the winter months.

While the advantages of effective ventilation are demonstrable, reaping these benefits in many built environments can nonetheless pose a challenge as it can entail the repeated adjustment of multiple windows.

This is particularly the case when windows are situated in hard-to-reach positions, or in large-scale built environments such as office complexes or group residential facilities, which possess a considerable number of windows in multiple rooms that are impossible to manually adjust en masse.

Window automation systems could provide the solution to these difficulties by unburdening occupants of the need to make regular adjustments to windows themselves in response to shifting environmental conditions, as well as facilitating the control of windows in hard-to-reach locations.

Much of buzz surrounding building automation systems (BAS) has focused on their ability to improve the efficiency of built environments via control of HVAC and lighting by adjusting such systems in response to the presence of occupants, time of day and environmental factors.

BAS lends itself more readily to the coordination of HVAC and lighting because they are internal mechanical and electrical systems that are much easier to integrate into a computerized control set-up.

New methods are fast emerging, however, to facilitate the automation of windows as well. They do so via the installation of various forms of mechanical actuators that enable either BAS or homeowners themselves to remotely control their operation.

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Cleanroom HVAC Strategies

[The following abstract of an article on HVAC design for cleanrooms and controlled environments is highly technical and the field…as technology is in general…is dynamic and continuously evolving.  It offers an excerpted overview of several key considerations.  Ultimately, your project’s unique properties…especially those of your process, product, research requirements and your physical plant…will determine best practices.]

Cleanroom HVAC design has two (2) critical concerns that can be considered different perspectives on on the same issue:

  1. Contaminants
  2. Control of the Environment

If the war on these manufacturing enemies are not won in the design process, the result can be millions of lost dollars due to insufficient product yield and compromised product integrity…hitting a company’s bottom line forcefully.


Optimal HVAC design solutions are determined by desired temperature and humidity control, air flow and pressure, and filtration requirements and air change rates…at the very least. These design factors are dictated by the requirements unique to your process, facility, and regulatory requirements.

Whether creating a controlled environment for an electronics manufacturer or a life sciences environment free of pathogens, the HVAC system controls your success and will significantly impact your operating costs.

Three (3) contamination fundamentals must be considered…regardless of the degree of desired air quality and cleanliness:

• Contaminants are never beneficial…begin by preventing their passage from outside into the work environment.
• Those that infiltrate your environment must be eliminated quickly.
• Besides worrying about particulate interlopers from the outside environment, make sure you have your own house in order. This means minimizing contaminants that your manufacturing or research processes—including the equipment integral to your operations—throw off, whether through biological, chemical, or operating processes. And make sure your employees consistently follow protocols developed to minimize contamination.

Cleanrooms demand an estimated 10 to 100 times more energy than standard office spaces…due to strict air cleanliness standards—and the HVAC system can account for more than half of the facility’s energy costs.  Following are a variety of strategies to help reduce energy costs related to your HVAC system:

  1. Minimize Demand. Take a look at your building. Can you increase the efficiency of the shell? When building new, carefully orient and develop the building form. Is there an opportunity to reduce the volume of your cleanroom? Less volume equates to less air re-circulation with resulting HVAC savings.
  2. Accurately scope the level of cleanliness and the square footage required. Going overboard in either category will drive up your costs. Considering reducing positive pressurization where prudent.
  3. Flexibility is key. Design your HVAC system with an eye towards flexibility, not only for sustainability, but for future product line and expansion capabilities as well. Remember to accommodate part load scenarios in HVAC equipment purchase.
  4. Subdivide your facility’s space classifications. Carefully examine the proposed process and product requirements when determining your required cleanroom classification. Don’t shoot an ant with an Uzi. Do you really need the entire space to be stringently controlled?
  5. Mini- and micro-environments are your friends; stick or prefab? Consider the use of micro- or mini-environments (see the May 2013 issue of Controlled Environments) and a mix of stick built and prefabricated areas—determined by process specifications and flexibility needs. Utilize these tools to meet your process requirements instead of upgrading your entire cleanroom.
  6. Invest in high efficiency equipment. Upfront costs are an investment with surprisingly short payback periods.

Read More – Controlled Environments