Tag: HVAC

HVAC Ductwork Design

Posted on by Lindsey Burbee

HVAC Ductwork Design

Have you ever wondered how HVAC ductwork is designed?

There are six methods for designing low, medium, and high-pressure HVAC systems:

 

  • Equal Friction Method
  • Static Regain Method
  • T-Method
  • Extended Plenum Method
  • Velocity Reduction Method
  • Constant Velocity Method

The most commonly used method is the Equal Friction Method. This method is used for low-pressure systems found in commercial buildings. It’s distinguishable by pressure loss per every 100 ft. of duct and is designed to be the same for the entire system. A well-designed system has an average friction rate of about 0.1” of water column per 100 ft. of duct length.

After determining the desired friction rate and CFM (cubic feet per minute) of airflow for a system, an air duct calculator properly sizes the ductwork that can support these requirements. The disadvantage of the Equal Friction Method is the lack of provision for equalizing pressure drops in duct branches. This only works if the duct layout is symmetrical.

 

 

Air Duct calculator for HVAC ductwork design

 

 

Why Is Duct Design Important?

HVAC systems are comparable to cardiovascular systems. Rooftop or air handling units are the heart, and the HVAC ductwork design is the body’s arteries and veins. Continuing this example, if arteries or veins are too big or too small, issues (such as high blood pressure or a stroke) can arise.

Comparatively, if ductwork is incorrectly sized, vital issues to the units can arise. Having ductwork that is too large can lead to a low CFM (Cubic Feet per Minute) of air flow in a given space. This can cause the unit to run longer in attempt to heat or cool a space. Inversely, having too small of ductwork can lead to high velocities and static pressures. This can create a loud environment and put unnecessary stress on the system.

In conclusion, incorrectly sized ductwork negatively impacts a system’s lifespan and energy expenses. Properly sized ductwork leads to lower energy expenses, longer unit lifespans, and more comfortable environments.

 

 

How Does a Melink Technician Verify Ductwork Installation?

While on site performing a Test & Balance, Melink technicians assess if duct systems are installed correctly. They analyze the duct system in the situation where proper airflow is unattainable. Unless unit total speeds are further adjusted to deviate from the design and rectify the imbalance.

As a result, Melink technicians reference mechanical plans, duct design tables, or an air duct calculator to verify proper duct size. Afterwards, they reference this to the given amount of air flow, then compare it with the installed ductwork.

 

 

A close up of a device Description automatically generated
This picture represents how air moves in ducts. Red areas have high static pressure, and green areas show high velocity.

 

Trained technicians inspect and identify dynamic losses areas, portions of ductwork with high friction rates and static pressure.

Dynamic loss examples due to installation errors are incorrect duct take offs, failure to include duct turning vanes, long runs of flex duct, or crimped flex duct. These issues can shorten the unit’s lifespan if not corrected. For instance, these issues can average costs of $1,200 per year extra in energy expenses.

Lastly, duct design discrepancies found during a TAB are reported and photographed for the customer’s reference.

 

 

Contributed by Andy Austin, Jeremy Neff & Anna Rusconi

 

TOP 3 Points to Consider Before Scheduling an HVAC Balance

Posted on by Lindsey Burbee

There are a few important items that you want to take into account before you schedule an HVAC balance. While these 3 points may seem obvious, there are many instances where a technician gets onsite and the job-site isn’t ready or they can’t access areas that they need. These tips can save time and money for everyone!

 

1. HVAC equipment is installed and operational.

This one seems like a no-brainer! However, there are always occurrences when a technician arrives onsite to perform a balance and necessary equipment either hasn’t been installed or isn’t properly operational. Examples include VAV’s or dampers that haven’t been installed, or a RTU that isn’t operational.

Ensuring that all ductwork has been completed, balancing dampers are properly installed, any grilles, registers and diffusers are installed, and the RTUs have clean filters helps make sure a technician can provide a proper air balance, as well as mitigate any potential return service costs. Making sure that all equipment (especially RTUs) has undergone a proper start-up to confirm power should always be completed ahead of Melink’s arrival.

 

2. All HVAC equipment can be easily accessed by a technician.

Another hindrance to any proper test & balance is not being able to access the necessary equipment. This includes equipment installed inside the building, as well as equipment on the roof. When working with a customer located inside a mall or shopping center, security and approved roof access becomes another added component.

Melink typically requires assured access to all applicable HVAC system equipment, including RTUs, VAVs, Exhaust Fans, dampers, etc. Access to fully open dampers, ceiling-height diffusers, and thermostats that may be in an office is necessary to properly complete the balance. Our Account Coordinators will also discuss roof access, security measures, and accessibility to ladders or lifts.

 

3. Allotting adequate time (2-3 weeks) to schedule and complete the balance.

Though some
seasons are busier (or slower) than others, our goal at Melink is to provide
every customer the same level of service excellence no matter the time of year.
This includes communication with the customer, scheduling the site visit with
one of our National Network technicians, performing the balance and working
with the customer on any punch-list items, and finally, providing a certified
test & balance report.

Our team of National Account representatives and technicians work with the customer through each step of the process. Scheduling an HVAC balance with Melink approximately 2-3 weeks out from turnover will help to ensure a proper and complete balance. It also allows enough time to work through any punch-list items or lingering comfort issues for the customer.

HVAC Systems – How to help ensure a good investment

Posted on by Lindsey Burbee

Life of an HVAC System

Heating, ventilation, and air conditioning (HVAC) equipment is similar to your car; it can last 7-20 years! The life expectancy largely depends on the quality of the equipment, and how the equipment is maintained. Without a maintenance log of all your systems, how do you estimate the remaining ‘miles’ your equipment has left? The answer – have an independent HVAC site survey.

Benefits of Site Surveys

Performing an independent HVAC site survey before purchasing new HVAC equipment, helps to ensure you are making the right decisions. During an HVAC site survey, or HVAC audit, independent partners help you determine the current state of your equipment. To do so, your independent partner should tailor a unique scope of work to help you with your specific needs.  HVAC site surveys can be complex with much focus on the fine details, or it can be a more general inspection of all equipment. Explain to your independent HVAC partner your situation and goals, then let them help you create a plan or program that suites your needs.

Self-Performing

“Why are you underlining independent?”, you might ask; because it is vital to ensure the gathered information is unbiased. Your partner should be a true owners advocate, working while looking through the eyes of the end owner. This task may be complicated for your equipment providers, preventative maintenance providers, and internal employees, there may be a conflict of interest in reporting one outcome verses another. One other important question to ask your independent provider is – “Are you self-performing?”.

You might be thinking – “Here we go again with these underlines.”, but self-performing is just as important as independent. Performing an HVAC site survey is a quality control related process. To fully achieve a high-quality result in your HVAC site survey, you should consider using a self-performing company. A self-performing company will use 100% of their own employees to survey your equipment. Therefore, the end product, or HVAC site survey report, is created from the findings of trusted partners or direct employees.

Once the time is right to replace or repair HVAC equipment, be sure to consider having an independent partner help you along the way. We’d appreciate if you’d consider Melink Corporation. We have a national network of self-performing technicians, and have been working with national and regional partners for over 30 years! Let us know how we can help!

Stay Ahead of HVAC Problems this Spring

Posted on by Lindsey Burbee

While many are excited to emerge from a long and cold winter and enjoy the rising temperatures that come with spring, not everyone loves the shift in seasons. Facility managers around the country dread the season change as it always brings lingering HVAC problems to the forefront. Every year during the spring and fall as temperatures are changing, buildings around the country work hard to adjust to the change in seasons as well. The HVAC systems go from cold temps outside and constant heating of the building to cooling instead, or vice versa. This dramatic change takes a toll on the building envelope and interior and can make underlying HVAC problems that went unnoticed during one season, suddenly very noticeable. Employees and paying customers alike are feeling the discomfort of hot and cold spots, condensation dripping, A/C not kicking on correctly, doors blowing open, and other annoyances.

These types of issues not only affect the comfort for your customers in the facility, they can also lead to long term maintenance and higher energy costs should they not be fixed quickly. This is where having an independent 3rd party onsite to inspect the equipment can assist. Hiring an independent company can help in identifying the underlying cause of such problems and repair minor issues that may have gone undetected for years. By having the facility inspected by a truly independent company, facility managers can know that the information they are receiving provides a truly accurate snapshot of their facility and is not biased or swayed based on loyalties. You will get real results with accurate and actionable information.

If you are experiencing any of these issues with the upcoming season change, it is recommended to have these issues investigated immediately. Prices begin to rise just as the temperature does in the summer, as construction demand is at its peak during this time. Seeing some of these issues in your building? Contact us here to talk with our team about ways to get in front of problems before they get worse!

The R-22 Phase-Out: What It Means and How to Best Prepare

Posted on by Lindsey Burbee

What is R-22?

R-22 is an HCFC (Hydrochlorofluorocarbon) refrigerant found in older commercial and residential HVAC equipment, such as RTUs (roof top units), split systems and other equipment.  R-22 and other HCFC refrigerants are known to deplete the Earth’s protective ozone layer and contribute to harmful climate change.

 

The US has slowly been phasing
out the use of R-22 per the following phase-out schedule:

 

  • 1/1/2010:
    The US government banned the use of R-22 in new HVAC equipment.
  • 1/1/2015:
    The US government bans the production and import of all R-22
  • 1/1/2020:
    The US government will ban the use of all R-22 (with a few exceptions).  This will be the end of the road for R-22 use in the US.

NREL (National Renewable Energy
Laboratory) estimates 40 million commercial RTUs (roof top units) were
installed in the US, in the decade prior to 2010.  The US Department of Energy also estimates
that are at least 1.6 million old, low-efficiency RTUs in operation in the
US.  This means there is a huge tidal wave of R-22 equipment in
operation that will need to be replaced in the very near future.

How does the 2020 ban affect me?
R-22 costs have skyrocketed and are already more than 4X the cost/lb. of
R410A. Older R-22 units have much lower EER ratings and are as much as 50% less
efficient than current-day high-efficiency units.  In most cases, older R-22 RTUs cannot be
converted to R410A refrigerant, and the older units will need to be replaced with a new, more energy efficient, more
environmentally friendly RTUs.  It is
already cost prohibitive to repair older R22 units, and the “fix-on-fail”,
emergency replacement philosophy will be MUCH more expensive than a pro-active
roof-sweep or planned equipment replacement program.

How can I best prepare for the phase-out, and where should I start?  I recommend companies start with an HVAC inventory of their older equipment, in addition to a detailed survey of all their facilities to verify the age and condition of all HVAC equipment, including newer and older HVAC equipment.  I also recommend involving a national or regional HVAC installation partner, and an independent, national testing, balancing and commissioning partner such as Melink Corporation to provide the unit data and a complete assessment of the entire mechanical system.  The survey should include duct-work inspections, inspection of the RTUs and exhaust fans.  Additionally, air-flow measurements should be recorded to verify proper building airflows and identify existing air-balance issues.  If the entire HVAC system is not inspected, the building will often continue to have comfort problems and building balance issues, even after the new equipment is installed.  The positive effects of the new, energy efficient HVAC equipment will not be fully realized, resulting in a lower-than-expected ROI.

 

 

  • For
    further information on HVAC surveys and other custom scopes of work, please
    e-mail [email protected]
    or call us at 513.965.7300.

Top 3 Points to Consider Before Scheduling a Balance

Posted on by Lindsey Burbee
  • HVAC equipment is installed and operational.

This one seems like a no-brainer, but there are always occurrences when Melink arrives to perform a balance and necessary equipment either hasn’t been installed or isn’t properly operational. Examples might include VAV’s or dampers that haven’t been installed, or a RTU that isn’t operational.

Ensuring that all ductwork has been completed, balancing dampers are properly installed, any grilles, registers and diffusers are installed, and the RTUs have clean filters helps make sure that Melink can provide a proper air balance, as well as mitigate any potential return service costs. Making sure that all equipment (especially RTUs) has undergone a proper start-up to confirm power should always be completed ahead of Melink’s arrival.

  • All HVAC equipment can be easily accessed.

Another hindrance to any proper test & balance is not being able to access the necessary equipment. This includes equipment installed inside the building, as well as equipment on the roof. When working with a customer located inside a mall or shopping center, security and approved roof access becomes another added component that must be considered.

Melink typically requires assured access to all applicable HVAC system equipment, including RTUs, VAVs, Exhaust Fans, dampers, etc. Access to fully open dampers, ceiling-height diffusers, and thermostats that may be in an office is necessary to properly complete the balance. Our Account Coordinators will also discuss roof access, security measures, and accessibility to ladders or lifts.

  • Allotting adequate time (2-3 weeks) to schedule and complete the balance.

Though some seasons are busier (or slower) than others, our goal at Melink is to provide every customer the same level of service excellence no matter the time of year. This includes communication with the customer, scheduling the site visit with one of our National Network technicians, performing the balance and working with the customer on any punch-list items, and finally, providing a certified test & balance report.

Our team of National Account representatives and technicians work with the customer through each step of the process. Scheduling service with Melink approximately 2-3 weeks out from turnover will help to ensure a proper and complete balance, and enough time to work through any punch-list items or lingering comfort issues for the customer.

Want to learn more? Contact us today!

Considerations for a Successful HVAC Equipment Upgrade Program

Posted on by Lindsey Burbee

Have you ever replaced old HVAC equipment just to find that, after spending a lot of money, the comfort issues you were experiencing previously are still there?  Or you now have new problems that weren’t there before?  Your HVAC operates as a complete system, and the new equipment is only as good as its installation quality and the existing system it is connected with.  Here are some tips to help you get the most out of your HVAC equipment upgrade program.

  1. First, be proactive.  Get ahead of HVAC issues before they get worse or before they occur at all.  The more proactive you are, the lesser the negative impacts to your facilities operating budget, revenue, customer relations, and human resources.  On the flip side, with a fix-on-fail approach, you deal with costly emergency repairs, you have high energy costs from inefficient equipment, your revenue and customer relations suffer as uncomfortable customers take their business elsewhere, and your human resources incur lost productivity and even turnover of employees due to uncomfortable/unhealthy working conditions.  Not to mention the effect on your stress level when you have to deal with HVAC breakdowns!
  2. Start with a site survey.  You need an accurate inventory of your existing HVAC equipment, so you can make decisions on what to do with it.  Be clear about what information you need to have collected from the field, information that will enable you to make a thorough evaluation and meaningful recommendations.  Examples include equipment age, condition, features, operating measures, and so on.  Remember that your HVAC is a system, made up of many components all working together.  The focus can tend to be limited to the heating/cooling equipment, but there are also other pieces of the system that are very important, such as exhaust fans, ductwork, air grilles, and controls, to name a few.  Issues with these other components could limit the effectiveness of any new heating/cooling equipment.  The system is only as good as its weakest member.
  3. Assess the data.  Review the data returned from the site surveys to assess the overall scale and scope of your upgrade program.  Determine your trigger points for repair versus replacement, such as equipment age, condition, and efficiency.  This is the methodology that will help you to objectively decide whether you will continue to invest in a piece of equipment or replace it altogether.  In grading the equipment, this could be a simple, Green – Yellow – Red system of classification.  Green meaning ‘do nothing’, the equipment is good as-is.  Yellow meaning ‘repair’, the equipment has some issues that can be corrected at relatively low cost.  Red meaning ‘replace’, the equipment has completely failed or is no longer worth investing in.
  4. Prepare a scope of work.  Apply the previously prepared methodology to your entire equipment inventory.  This then becomes your scope of work for each site.  Put the scope in writing and be clear about your expectations.  Your equipment suppliers and installation contractors will need this scope in order to provide you with accurate estimates of cost and lead time.  This advanced planning, budgeting, and coordination will help to ensure the subsequent execution of the work goes smoothly.
  5. Consider the timing.  Equipment suppliers and installation contractors tend to be busiest in the summer and early fall months when construction activity peaks.  Avoiding these times helps to ensure you have the support you need, and your costs may be lower.  Plus, upgrading before summer helps to prepare your facilities to handle the hot/humid weather ahead.  Any temporary outages of heating/cooling that may occur while equipment is being repaired or replaced is less impactful on the facility operations during times of milder weather.
  6. Vet your partners.  Working with the right people makes a world of difference.  Partner with suppliers and contractors who are trustworthy and reputable.  Make sure they have experience with your type of facility and HVAC system, and are qualified for the services to be performed.  With the right team, you can accomplish most anything.
  7. Inspect the work.  After the equipment is repaired or replaced, it is imperative that it be inspected, tested, balanced, and commissioned in order to receive the full benefit of your capital investment.  This is your final assurance that you get the quality and performance expected out of your HVAC system.  When issues are uncovered during this process, be sure to have them corrected by the suppliers and contractors while they are still under warranty.  If left unaddressed, those issues will become headaches and costs to your facilities and operations teams later.

Managing an HVAC equipment upgrade program can be a daunting job.  When it is handled in a proactive and organized fashion, and includes the right partners, the results can be extraordinary.

The 3 Most Common HVAC Problems During Winter

Posted on by Lindsey Burbee

To quote a critically acclaimed HBO television series, “winter is coming, and we know what’s coming with it.” While it may not be as bad as the army of the dead, we can expect winter to bring about a variety of HVAC issues that can cost more pennies than shivers. Here are the top three most preventable winter mishaps, and how they can be avoided with a little DIY maintenance.

  1. Frozen Pipes

Besides fire, a building’s biggest enemy is water. Only this time of year, unwelcomed water doesn’t come in the form of humidity or a leaky roof, rather, in the form of solid icy pipes. Many building owners will try to cut costs by not heating their buildings at all times while completely unaware that above ceiling and sub-floor spaces can fall below zero in extreme cold weather. These spaces are home to water pipes that can freeze and burst causing un-flushable toilets, compromised showers, inaccessible tap water, and not mention, outrageous repair costs. The residual heat from the livable spaces above or below these pipes help to keep temperatures above freezing, so setting the thermostat to at least 65 °F throughout the day and night should keep the water flowing. In addition, be particularly aware of areas that are unheated or are constantly exposed to the elements like garages, loading docks, and basement storage rooms. Insulated pipes and walls will help to seal the deal.

  1. Uneven Airflow and Temperatures

Depending on the season, air is circulated throughout a building in different ways. Cold air falls which is why in the summer months, closing floor vents to allow more air to diffuse from ceiling vents is most effective in cooling a space. The opposite is true in the winter months where rising warm air is best circulated from floor diffusers and baseboard radiators. Knowing these trivial properties about air temperature can best optimize how your building is heated or cooled, so let the cool air fall and the warm air rise!

  1. Dirty Furnace Filters

While problems that arise from dirty or clogged filters are not unique to the winter, it’s still one of the most common culprits for defective air conditioning. A unit’s air filter removes particulates from the pre-conditioned air and allows the clean air to be conditioned and distributed. If a filter is clogged, airflow is reduced, and the terminal units will have to run longer to achieve desirable space temperatures. In the colder months, the air becomes dry which can dehydrate a person’s skin as a result. With dead skin cells making up 70 to 80 percent of dust content, it’s no wonder that the winter sees some pretty dirty filters. Changing an air filter is one of the easiest, cheapest, and most effective way to ensure maximum heating outputs which is why new filters should be installed before every season.

These winter mishaps are snow laughing matter, but just like bad puns, they’re easy to spot. Keeping these three common maintenance issues in mind will allow you to brave the cold and keep cozy all winter long.

The Test and Balance Professional

Posted on by Lindsey Burbee

The HVAC industry is vast; there are many products and services that make up the build of any one system. Test and Balance is a very important niche of the large HVAC industry. Many HVAC companies have offered test and balance services throughout the years, but very few of them have employed technicians dedicated specifically to Testing and Balancing. Enter Steve Melink, circa 1987. Steve knew there was a service gap in the HVAC industry and addressed it. Does it really make sense for an owner to allow an installing contractor to verify the HVAC system they installed is correct? Would it not make more sense if an INDEPENDENT, CERTIFIED and SELF PERFORMING entity verified that the mechanical engineer’s design was met? Of course, it would!

Fast forward 31 years and Melink Test & Balance is still going strong thanks to our dedicated team of technicians. These Balancing Professionals are dedicated to Melink Corporation’s core values of Integrity, Innovation, and Service Excellence.

What is a Test & Balance Technician and What Do They Do??

Our National Network consists of more than 30 professionals across 19 states. Our technician tenure’s range from 15 years to less than a month! 100% of Melink balancers are NEBB trained with more than half of the network being NEBB Certified Technicians. Our technician’s experience prior to Melink varies from HVAC service technicians to general contractors to aircraft systems mechanics. Our team currently services more than 50 major accounts and we are adding more every year. As you can imagine, Melink Technicians have seen nearly every type of commercial HVAC unit utilized by the commercial retail market. There is no typical ‘day in the life’ for our T&B technicians. Between the location, business type, and scope of work, every week is a new adventure!

The lifestyle of our techs is unique, but very rewarding and profitable. All techs are road warriors, traveling across the United States each week to different jobs. Melink covers all travel expenses and supplies each tech with a company vehicle. Not only does this allow the team to see the U.S. on the company dollar, but their personal expenses decrease since most of the week they are being covered by the company. Food, gas, and vehicle expenses add up!!

This position is also very independent and needs a disciplined self-starter. With most projects only needing one tech, most of the travel and work is done alone. Even so, the Melink National Network is a family. Each tech knows that a fellow balancer or office support is only a phone call or an email away if they are ever in a tight spot. Even after hours, our technicians constantly interact with one another to help each other grow and support our customers. This is not just a career or a steady job, this is a lifestyle.

On top of it all, our technicians are also partial owners of the company. Melink Corporation is now an ESOP (Employee Stock Ownership Plan), which gives all Melink employees even more incentive to push the envelope with innovation and succeed as a business. Thanks to our National Network Technician team, Melink Corporation has been listed as a Best Place to Work for 3 consecutive years. Melink Corporation encourages input and recommendations for improving the business and improving the lives of the technicians. Melink works hard to address everything to better the position and the experience, for our employees. Striving for the best possible work/life balance is something very important to Melink Corporation.

One can find challenges in any profession they choose. But Melink’s National Network chooses to be challenged on a daily basis and to thrive in it! Their dedication and their commitment to service excellence is the backbone of Melink T&B!

Click here to learn more about Melink T&B.

Committed to You: A Customer-Centered Focus

Posted on by Lindsey Burbee

Customer Service Excellence is not only our responsibility, it is the cornerstone of our values at Melink. Since 1987, we have made a conscious effort to make the customer our sole focus each and every day, working to create the absolute best customer experience possible.

This year, in an effort to provide a greater experience for our Test & Balance customers, we restructured our internal account teams. Our decision to revamp our customer service team’s layout was in response to our ever-growing business, and the continually changing nature of what it means to provide a first-class experience. We choose not to be complacent, but rather question daily whether we are utilizing the most efficient customer service tactics in executing our goals and serving customer’s needs.

The new teams are made up of a dynamic group of skillsets to ensure a well-rounded support system, with the customer as the center focus. There is an Account Manager that acts as the point-person in daily communications; an Account Coordinator or Specialist who works directly with customer site contacts to effectively and efficiently schedule our National Network; and an Account Engineer offering specialized technical support for their team’s customers.

We even restructured our office space and customized our email system to provide a more cohesive and resourceful team environment. By rearranging our internal office space, our team members can better communicate proactively and at the speed of business. By providing account-specific email addresses, our customers have the comfort of knowing they are communicating directly with a dedicated team focused on their needs. By scheduling our National Network more effectively, we increase productivity and meet our customer’s needs in a timely and efficient manner.

To most, our Test & Balance division is known for providing first-class HVAC services. We go beyond what others in the industry do. We offer more than just a balance – a hands-on support system providing a full customer service experience from order to invoice!