There are many parts that compile a buildings HVAC/R system and the coils are one that can have many effects on the buildings conditioned air space. Coils are an integral part of any HVAC/R system and as with any main component; proper care should always be taken. For any system to run at its optimum performance having clean coils and filters is imperative.

Coils need to be clean in order to reach the units full capacity. Clean coils also allow the full efficiency, indoor air quality, and long term system performance goals to be reached. Coils which are dirty and have blocked air flow will lose significant capacity; causing the unit to run harder and longer to reach desired temperature, if at all. This causes loss of efficiency, which in turn raises energy consumption and can drastically raise a buildings energy costs.

Another side effect from a dirty coil is the decrease in unit life. Dirty coils cause the unit to run harder and longer, causing a breakdown in the compressors lubricants, leading to mechanical failure. These conditions can also lead to acid formation, which can cause acid burnout. Coils that have an accumulation of dirt cannot transfer heat, causing the compressor to run harder, this adds more heat and raises head pressures by a significant percentage. Having a higher head pressure also reduces the systems cooling capacity by a considerable amount. These conditions will be noticed most on hot days when the system is required to do the most cooling.

Coils are engineered for maximum heat transfer and are sized to match the buildings Btu cooling load. A major factor in achieving the engineered heat transfer specifications and building cooling load is dependent on the cleanliness of the coil. Coils are constantly having air transferred over them and as a result air particles are moving over them as well. These particles cause the coil to become dirty and do not allow for proper heat transfer when dirty.

The condenser coil or outside coil is commonly known as the “warm” coil because it rejects the heat using a fan to blow outside air over the coil. Outdoor coils are generally unfiltered and become a magnet for any airborne materials that may be around. If the outdoor unit or building is located in a construction area or industrial area the amount of airborne particles increases significantly. Coils which are located near high particle areas should be inspected and or cleaned more often than those which are not in these types of areas. Condenser coils should be thoroughly cleaned by a professional, licensed contractor at least once a year.

The evaporator coil is the indoor coil and is commonly known as the “cold” coil. The evaporator coil is known as the cold coil because it is the coil that provides indoor cooling for the building. This cooling is achieved by the coil absorbing hot air in the building and converting it to cold air, which is then sent throughout the buildings duct system. Indoor coils should have filters in place and filters should be changed on a regular maintenance schedule. Having dirty filters can also lead to loss of efficiency and capacity with the unit. Along with changing the filters on a schedule, filters should be checked for cleanliness and overall integrity; while changing the filters coils should be inspected for any issues. Dirty filters do not allow air to flow through to the coil for and in return negatively affect the heat dispersion.

Additionally the coil and its condensate pan can become fouled up with mold, pollen and many other particles. These conditions can negatively affect the indoor air quality of the building. Having clean filters is only part of the equation for proper system functionality. Evaporator coils are the major factor in the equation, with a clean filter and coil the energy consumption will be significantly lower.  

All coils should be cleaned by a professional contractor no less than once a year. Coils should be checked often for visible decay of the fins, dirt and any other materials that will hinder the coil efficiency. A proper coil cleaning may well result in increased capacity and lower energy consumption, resulting in a lower utility bill while increasing tenant satisfaction. In order to properly clean coils and remove all particles professionals must use particular equipment. This equipment should be used only by professionals because damage could result to coil fins if used improperly. Technicians also have an array of cleaners and agents that are designed to bring out dirt from deep within the coil. If coils are not cleaned by a professional, cleanliness and capacity of that coil may never be reached.

Coils are an extremely important part of the system, having clean coils coupled with filters can lead to lower energy bills and longer unit life. Coils as well as filters should be inspected on a regular basis and coils should be cleaned by a professional on a minimum of an annual basis. Keeping up with a buildings coil cleanings and filter changes will help out in many areas, both short and long run.

• Ensure that unit refrigerant charge is at proper level, service contractor to check and adjust charge properly.
• Keep the house closed tightly during the day, leaving windows and doors open lets unwanted heat into the conditioned air space and causes the unit to work harder.
• When shopping for a new central air conditioning, purchase the highest SEER unit that is financially possible. Higher SEER units are more money in the initial purchase but will pay for themselves through cutting energy bills
• Install a programmable thermostat, installing a programmable thermostat allows you to vary temperature based on time and vacancy, which also lowers the energy consumption.
• Make sure that the condenser is located in a shady spot and has room to dispose of heat from the conditioned space. Don’t crowd the condenser with bushes or shrubs.
• Consider installing reflective window tint to reduce the amount of heat entering the home.
• Turn off lights when not in use, lights produce heat which causes the system to work harder than needed.
• Seal any air leaks that may be present around windows, doors, etc. These leaks cause outside air to enter the conditioned space and make the system work harder.

 These tips coupled with last publications tips and a service plan will help increase unit life; all while lowering energy consumption and saving money!  These tips do not replace the need for a professional maintenance plan, which should be in place for all units. If you have any HVAC/R questions or needs contact us at (305)826-2240

Saving money is always a good thing and in some cases it can be easier than you may think. Here are some tips that may help you save money with your air conditioning system and will cost you little to nothing:

• Set your thermostat to a temperature as high as comfort will allow, each degree set under 78 can increase energy consumption substantially
• Check your filter on a monthly basis and change when need be. Dirty filters can cause considerable efficiency loss in the system
• Ensure that there are no heat creating devices near your thermostat, this can create a false reading and make the unit run harder and longer than needed
• If possible, wait until the evening to participate in heat creating activities such as baking and running the dishwasher, this will help lower the cooling load and desired temperature will be maintained and achieved easier
• Try to shade east and west facing windows, keeping the sun from shining into the area will also help achieve and maintain temperature easier

These are a few tips that can help lower cost and increase your unit’s life when followed. While these tips are great in many aspects, they will not replace the need and effectiveness of a professional maintenance plan. If you liked these steps, check back in the near future for more great HVAC tips!

We are looking for qualified individuals to fill the role of:

Service Technician.

The position is available to start immediately and the job description is below. DebonAir Mechanical is a Drug Free workplace and you will be required to pass a drug test. We are accepting resumes for our East Coast, West Coast, and Keys offices. If you are interested in submitting a resume please email it to paleshire@debonairac.com. Click the blog Title to view the job posting. We look forward to hearing from you!

Title: HVAC Service Technician                 Position Reports to: Service Manager

Salary range: Based on experience or skill level       Status: Full-time

Description: Family-owned and operated air conditioning, refrigeration and heating company seeking HVAC Service Technician for commercial work.  The right candidate will have an opportunity for upward mobility in multiple areas of the industry as well as bonuses and excellent benefits.

Applicants must have exceptional communication skills; able to work with a diversified selection of commercial equipment and technical instruments (see below); have a minimum of 5 years training and field experience; must possess valid driver’s license; can maintain basic job records and manifests indicating job assignments, and time records; needs to be a team-player; must be able to pass drug/background check.

Qualification:

• 5+ years experience
• Inspect, diagnose, and perform emergency and/or preventative maintenance on commercial HVAC systems and equipment.
• Troubleshooting, maintenance and replacement of belts drives, filters, seals, motors, pumps, etc. for commercial equipment
• Maintain necessary equipment and building system logs and records
• Clean, lubricate and service a wide variety of commercial pumps, valves, digital pneumatic controls
• Overhaul and service commercial air conditioning and refrigeration units by repairing, replacing or adjusting worn or broken parts on condensers, compressors, water pumps; tests equipment for refrigerant leaks.

Equipment:

Chillers                                                      Cooling Towers

Air Handlers                                             Package Units

Split Units                                                 Heat Pumps

VAV Boxes                                              Compressors

Motors                                                       Variable Frequency Drives

Duct Work                                                Thermostats

Refrigeration Systems                               Ice Machines

To apply please submit a resume with contact information to paleshire@debonairac.com or fax it in to (305) 826-2966 Attention: Human Resources.

Space is one of these issues. Air cooled chillers can utilize open space, such as a parking lot, roof or ground level area. Water cooled chillers are smaller in size, but require a mechanical room and cooling towers. On the flip side, air cooled chillers can have serious issues with recirculation if there are walls higher than the unit or too many units to close together. If there is a situation where outside walls are required for building code and the unit will not be receiving enough fresh air, then a water cooled application may be the best option.

Sound is another issue than may come into the equation. With any chiller sound is inevitable, air cooled chillers generally have a different decibel because of their fans. There are things that can be done to reduce the sound on chillers, but the best way to negate the sound is to purchase a quieter unit upon decision.

A major part of the equation these days is cost. A detailed cost vs. benefit analysis is advised in any major equipment change. While one chiller may have lower initial costs, it may also have a shorter life span and higher operating costs.

Lifespan is huge in the decision of which unit to choose. Talk to a local contractor, to find out what kind of lifespan they have seen from units similar to those being looked at for the building. There are steps that can be taken to increase lifespan on many units. When speaking with the contractor ask them about these additional steps to ensure the longest life for the unit.

With so many decisions being based on cost and purely cost alone, quality is sometimes thrown out of the equation. Quality is a major factor of the equation and should always be thought of. Quality of the product and the contractor who will be doing the job are both very important.

When it comes time to install a new chiller, these points should help in that field. There are many advantages and disadvantages to both kinds of chillers and some of those are listed below:

  Air Cooled Advantages                                 

• Install cost is generally lower
• Less Maintenance depending on application
• No need for a mechanical room          
• Cooling Tower not needed    
• Condenser pumps not required          

Water Cooled Advantages

• Usually have a longer life
• Higher efficiency 
• Indoor placement
• Larger tonnage capabilities
• Refrigeration containment

Air Cooled Disadvantages

• Generally less efficient
• Life span is not as long
• Usually have more operating noise

Water Cooled Disadvantages

• Additional maintenance costs
• Water treatment costs
• Mechanical room needed

DebonAir Newsletter Apr2010

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A chiller with a 5 year life which has been properly maintained and logged can be 20-25% more efficient than if that same chiller had not been properly maintained. With these numbers in place a chiller whose full-load efficiency was .60 kW per ton would jump to between .72 kW per ton and .75 kW per ton if not properly maintained.

Knowing these numbers it is easy to understand why your building should have a proper maintenance plan in place. While the upfront cost of the maintenance may look expensive, it will save you and your building money in the long run. The lower utility costs and upkeep of the equipment will offset the maintenance cost sooner than many would expect.

Having the proper maintenance in place is vital to getting your machines(s) to run at peak efficiency and this starts with keeping a chiller log. Recording chiller operating parameters regularly can provide vital information and inform you of any changes or hiccups that your machine(s) may have. Catching these changes before they become major problems will save you and your building money and headaches. While the majority of buildings have chiller logs, many of these logs are not reviewed on a regular basis and that is an essential part of the maintenance.

Other important elements in keeping the chiller running at its peak efficiency are inspections; they may be based on a monthly, quarterly or yearly basis. These inspections form the foundation of any chiller maintenance program and should include but not be limited to the following:

-Inspection of condenser water and chilled water pumps operating pressures/ temperatures, amperage, and voltage

-Lubrication of motors, pumps and bearings per manufacturer’s recommendations

-Oil analysis

• Lets you know of metal wear, contaminants, viscosities and inhibitor levels.
• Allows for easy trending of condition of oil

-Annual inspection: cleaning of condenser water tubes for chillers (requires shut down and ideal time to do this is winter), oil changes and dryers, and servicing of purge units

-Vibration analysis

• This test indicates an imbalance, misalignment, bearing defects, open rotor bar conditions, gear wear, harmonics, and excessive shaft run-out.
• It gives you the ability to schedule machine overhauls, helps you save on unnecessary overhauls, predict machine failures and reduce maintenance costs.

- Eddy Current test of vessels

• Eddy currents test the heat exchangers and look at the inside and outside diameter defects
• These test will also let you know the severity of the defect and whether immediate action should be taken

- Infrared test of electrical connections

• Indicates loose connections which create overheating to motor windings and reduced life expectancy of motors/ compressors.
• Helps determine whether the chiller is running as efficiently and reliably as possible.

With all of these maintenance solutions in place your building can use less energy and run more efficiently. DebonAir can customize any maintenance plan to fit you and your buildings needs and get you running more efficiently and more aware than ever before.

DebonAir Mechanical is now hiring!

We are looking for a qualified individual to fill the role of Assistant Service Manager. The position is available to start immediately and the job description is below. If you are interested in submitting a resume please email it to paleshire@debonairac.com. Click the blog Title to view the job posting. We look forward to hearing from you!

Title: Assistant Service Manager

Position Reports to: Service Manager

Start date: ASAP Status: Full-Time

Salary Range: 38K – 42K salary

Hours: M-F  7 AM to 5 PM

DebonAir Mechanical’s Assistant Service Manager must first and foremost possess a complete understanding of the company’s philosophy as partners with our clients, our employees, our communities and the environment. In maintaining the company’s high ideals and standards, the Assistant Service Manager will report to the Service Manager, and perform various duties which assist the Service Manager in ensuring that DebonAir’s Service is prompt, professional, and accurate. The individual selected for this position will be required to operate in a team environment and to function at a high level within this team. The candidate will also need to be capable of operating at a fast pace and still maintain accuracy and attention to the job at hand. Organization is a key component of accomplishing this. Job functions include but are not limited to the following:

Assistant Service Manager Primary Job Functions:

• Assist Service Manager with whatever needs he may have.
• Support dispatcher at various times by receiving service calls from customers and dispatching technicians to pending service calls accordingly.
• Generate estimates for service work which customer needs to have completed.
• Generate service proposals based off of estimate sheet and submit to customer.
• Support technicians in the areas of troubleshooting and job knowledge pertaining to completion of HVAC/R repairs and installations.
• Have a working knowledge of DebonAir’s client base and become familiar with various client contacts and client’s equipment.
• Maintain a schedule of pending jobs and ensure the full completion of those jobs’ life cycles.

Required experience:

• Ability to work well in a fast paced environment with other team members.
• Solid and robust knowledge of HVAC/R and Mechanical systems including various troubleshooting techniques on equipment ranging from chillers to refrigeration.
• Various computer skills:
  • Microsoft Word
  • Microsoft Excel
  • Microsoft Outlook

Ability to learn new software

A newer credit that has been put into the LEED equation is Cooling Tower Water management. There are a total of two possible points available towards the LEED certification in this credit. The intent of this credit is to lower the amount of potable water used for cooling towers through the proper management of the tower and its water.

There are two options to achieving the points, option one is through a Chemical Management plan. The chemical management plan needs to be well developed and implemented. The plan must cover the towers chemical treatment, bleed off, biological control and it must also incorporate staff training as it relates to the towers treatment. Another part of this plan should be to increase the water efficiency by installing automatic controls and conductivity meters. Option number two is through Non Potable Water Use. Option number two can be achieved by using at least 50% of non potable water for the buildings cooling tower system. Some of the ways to reach the non potable requirements are through the use of harvest rainwater, storm water, cooling tower blow down, and recycled treated waste water from toilets and urinals. In order to get the point there must also be a measurement system in place, which is calibrated to manufactures recommend intervals. In order to receive both points the building must achieve both of the requirements under the Cooling Tower Water Management credit.

LEED has incorporated the energy star rating system into their point system in an enormous way. Energy and Atmosphere are major ways to get points on the buildings certification. HVACR systems take up the majority of buildings energy and in turn are a great way to earn points when trying to earn any of the LEED certifications. Points are awarded based on the buildings energy star rating and the points increase accordingly with the buildings increase in energy star rating. The building must have energy meters that measure the building throughout the performance period. The time period for performance measurement must be a full twelve months of consecutive readings.

The energy and atmosphere section of the LEED certification offers multiple options on how to save energy and money for the building and its owners. Another way to earn points and save is the building commissioning credit. The intent of this credit is to have a true understanding of the buildings major energy using systems, have options for maximizing the energy performance on those systems and put together a plan to achieve those energy savings. There are two possible options for this credit and a total of two points available. Option number one is the commissioning process. This option covers developing a ongoing commissioning plan or recommissioning, documenting the breakdown of energy use in the building, listing operating problems and putting together capital improvements that will provide cost effect energy savings. Option number two of this credit is the ASHRAE Level II energy audit. Earning this credit takes and energy audit that meets the requirements of ASHRAE level II, documented breakdown of the energy use in the building, perform a savings and cost analysis, as well as list the capital improvements that will improve cost effective energy savings.

Indoor Environmental Quality provides many options on earning points through the buildings HVACR system as well. IEQ credit 1.2 Outdoor Air Delivery Monitoring is one of those options. The intent behind this credit is to help sustain occupant comfort and well being through ventilation system monitoring. Studies have shown that monitoring Indoor Air Quality leads to more productive work and generally happier building occupants. The requirements of this credit are to install permanent, continuous monitoring systems to ensure that minimum outdoor airflow rates are constantly being met. Another possible point earned is the IEQ credit 1.3 Increased Ventilation. The intent of this credit is to provide further outdoor air delivery to improved indoor air quality and the well being of the buildings occupants.

There are many options for lowering the buildings energy costs and at the same time increasing the well being of the buildings occupants. This article only covers a few of those options, but gives an idea of how important a buildings HVACR system are in the LEED process. For further information on how to achieve possible points and lower your energy, contact DebonAir Mechanical.

Cooling Towers are a main part of the HVAC system in many buildings and just like any other mechanical piece; towers should be properly maintained to assure optimum performance and efficiency. A major part of ensuring you get the proper life and operation out of your towers is to keep up with the water treatment in the tower. Here are a few reasons why keeping up with the tower’s water conditioning can increase the life of your tower:

Corrosion:

Corrosion is an inevitable part of having a cooling tower and it cannot be completely eliminated. Corrosion needs to be controlled to the proper pH levels to help pacify the waters natural corrosives. South Florida waters require that the conductivity be maintained above 1500 to 2000 parts per million, elevating the pH to above 8.6 in order to properly control the corrosion in the system.  Unnecessary corrosion can cause higher costs, due to premature failure and it will also lower your towers efficiency.

Determining Acceptable Corrosion Rates:

Corrosion rates should be balanced in conjunction with the projected life of the equipment to determine if they are acceptable. Corrosion rates should be monitored to verify the corrosion control in the system. Mild steel corrosion rates should be maintained at less than 1.5 mils per year. Copper corrosion rates should be maintained at less than .2 mils per year.

Conductivity:

Conductivity is the measurement of total dissolved solids. Tower water is cycled to reduce water usage in the tower. The cooling tower removes the heat from the water, through evaporation. Minerals and solids increase and cycle up over time as the tower continues to evaporate water. There are two variations of conductivity and they are low and high conductivity.

High conductivity (above 2200 parts per million) could cause scale deposits to form in the condenser tubes, tower and condenser piping system. High conductivity will be a sign of excessive scale in the tower, which will transfer through the piping into the strainers; this will decrease the water flow into the condenser and will cause a loss of heat transfer in the heat exchangers. Immediate action must be taken to lower the conductivity below 2200 parts per million.

Low conductivity is quite different than high conductivity, low conductivity occurs when water is lost from the cooling tower. There are two main reasons for low conductivity in the tower and they are: the tower overflowing due to excessive water and improper make-up float operation. The solenoid bleed line should also be checked in order to ensure that excessive water loss does not occur. Loss of water in the tower will cause the system to pump more city water in than necessary, which will in turn raise your water costs and lower your efficiency.

Biological Fouling:

Biological fouling is the accumulation of microorganisms, plants and algae on submerged structures. The cooling tower fans draw these contaminants into the tower with the air and they are introduced to the water. Sunlight increases the development of algae and other biological matter, increasing the growth rate of these contaminants. Algaecides are used to control these growths and to ensure that they do not reach unacceptable levels. To keep the biological fouling at proper levels, dual algaecide systems should be used. The system should consist of a liquid algaecide and an oxidizing algaecide. If algae and slime already exist in the tower, the tower should be shocked and pressure cleaned to remove the biological fouling.  Algae and slime in the system can be hazardous to the occupant’s health. It can also plug the hot basin distributors, this would cause the hot water overflow basin to overflow and this would reduce the GPM and decrease your efficiency. Scale and algae in the system will also decrease the cubic feet per minute, which will cause the fan to run harder, causing unnecessary stress on the system and decreasing efficiency.

Keeping your cooling towers water at an optimal balance can save your building money in the long and short run, by running the system as efficiently as possible. It can also save you money by decreasing your operating and maintenance costs.