HVAC Commissioning--Why You Need it

HVAC commissioning can enhance the lifespan
 of your mechanical equipment. 

What is HVAC Commissioning?  

HVAC commissioning is a thorough and comprehensive testing of a mechanical system's performance.  Many owner's are less than eager to spend more money, when they are already spending money to the contractor or engineer to fix the problem.   What most owner's don't realize is that commissioning can extend the life of equipment, while reducing operating costs and increasing the comfort of occupancy.

While the equipment should be properly installed in theory, there is not always sufficient evidence that the system is operating as optimally as it was design.  Varying operating conditions can certainly affect the equipment's ability to function properly.  It is usefully after the installation that the user discovers problems, and many times will attempt to fix the problem with patch and it makes it impossible to go back to the original intent of system.

Commissioning Process

Typically the commissioning contractor is the original contractor who installed the work, while the commissioning agent is the engineer who designed the project or was involved with the design process. The agent will stimulate a variety of operation conditions and work with the contractor to determine if the system is responding properly.

If discrepancies are noted, they will be diagnosed and resolved during the commissioning process.  Once, this is completed, the equipment is turned back over to the owner in perfect condition and in mechanical systems should be commissioned.

Any project with an automatic control of mechanical systems should be commissioned including:

• air conditioning unit 
• heating or cooling plant upgrades 
• project involving replacement or installation of automatic valves or dampers
• any installation or replacement fans, heating and ventilating units and duct heaters 

Looking for a competent engineering firm to commission your mechanical system?  RGD Consulting Engineers has 35 years of experience and can make sure your facility is operating effectively and efficiently.  

Sick? Your Air Conditioning Could be the Cause

Is your air conditioning making you and your family sick? 

For many, air conditioning is the embodiment of comfort living, particularly in the summer months when the heat index can be unbearable.  But could your air conditioning be causing more harm than good? 

According to the Director of the Common Cold Centre at Cardiff University in Wales, Professor Rob Eccles, exposing the body to extreme temperatures could actually make you sick. 

 Here's Why: 

As warm blooded animals, the human body's optimal temperature is around 98 degrees Fahrenheit. In extreme cold environments the body will fight to maintain this body temperature.

Cold temperatures cause blood vessels
 to  constrict and diminish number 
of white blood cells.

One of the body's defense mechanisms against the cold is the thermal regulator in the brain. As soon as it receives a message from the temperature sensors in the skin, the blood vessels are alerted to constrict. This immediately causes a person's skin to become ashen or mottle, which is quickly followed by shivering in order to generate heat to raise the body temperature. 

As a result, the blood vessels in the nose and throat, both of which are favorite locations for bacteria and viruses to hide, will constrict therefore limiting blood flow. 

As the blood flow diminishes, the white blood cells that typically fight bacteria and viruses do too. This allows these dormant risks to develop in to colds. Low blood flow to the throat means that there isn't enough white blood cells to ward off infection. 

Sweating exacerbates the problem because it keeps the body colder. This makes it more of a challenge for the body to maintain its optimal temperature. 

Going from hot to cold environments could put
you at risk for a cold. 

Professor Eccles emphasizes that a cold will only develop if the bacteria or virus is already present in the body.  

This phenomenon occurs when going from a hot environment to a cold atmosphere not the other way around. Though, Professor Eccles recommends limiting the number of times you go from a cold environment to the hot outside as when your body acclimates to the heat and steps back inside the chilling cycle will begin again. 

This article was derived from the headline "Does Going from Hot to Cold Cause Colds?" which appeared on August 20, 2013, in the U.S. edition of The Wall Street Journal. 

What’s so special about Clubhouses?

Ballen Isle Country Club
West Palm Beach, Florida

The Complexities of Designing HVAC Systems for Clubhouses  

Clubhouses are unique among buildings. They house restaurants, community centers, banquet halls, entertainment complexes, retail spaces, fitness and spa centers and even offices all wrapped up into one facility! 

Dripping Diffusers

The clubhouses' unique nature is one of the major reasons why faulty HVAC systems are common; especially in humid climates such as Florida.

Perhaps, one of the most frequent issues that engineers uncover during a due diligence survey is a facility operating under a severely negative air pressure condition.

Common Symptoms of Negative Air Pressurization  

•  A lack of fresh or clean air, instead a musty smell or other bad odors lingering in the air
• Condensation on the Diffusers
• Visible Mold or Mildew Growth along with Moisture on the Walls 
• Sticky or Damp Furnishings
• Varying Temperatures Throughout the Facility 
• Stagnant, Stale or Heavy Air that causes Humidity or Condensation 
• A Rush of Air or Draft when Opening an Exterior Door 

According to Bob Davenport, RGD Consulting Engineers' Principal Engineer, who has over 35 years of experience designing HVAC systems, "Operating a clubhouse with severely negative pressure can result in serious indoor air quality problems over time." 

Solutions

 If not caught before the start of microbial growth, negatively pressurized facility can be a costly issue to rectify. This is why having the proper HVAC equipment and a good maintenance program is important to preventing issues such as negative air pressure from occurring. 

Ensuring that the clubhouse building is equipped with 100% outside air pre-conditioner, runs continuously and supplies a constant and equal volume of dehumidified outside air to the building is key to maintaining the air pressure. 

There are a variety of methods for achieving this goal, and the most effective HVAC design system can be determined by a professional engineer after completing a thorough survey of the facility's systems. However, even the best designed HVAC systems can fail when they are not maintained. 

Just as important as working closely with an engineer for the design of your facility's HVAC system, is the creation of an aggressive maintenance program.   With these two factors planned well, your facility's HVAC system will stay balanced and healthy for years to come. 

This article is adapted from "Is Your Clubhouse Stuffy" written by Robert Davenport, PE, LEED AP + BC.