EXPERIENCE SPEAKS: HVAC
Retail Facility Business asked several experts about HVAC issues pertaining to retailers and shopping centers, specifically about readying their stores for summer and the impending 2010 phase-out of R-22 refrigerant. Our experts are: Mark Barraclough, president of New Britain, Pennsylvania-based Alpine Mechanical Services; Dennis Burke, president of Covington, Louisiana-based Responsive Service & Maintenance Company; Don Langston, vice president and general manager of Southern California-based Aire Rite Air Conditioning & Refrigeration Inc.; and Ron Prager, executive vice president of Freeport, New York-based Brinco Mechanical Services, Inc.
RFB: What do retailers and property managers need to do to get their facilities’ HVAC units ready for summer?
Mark Barraclough: The most important thing to do to keep equipment running efficiently is to have HVAC units cleaned and overall operations tested. Routine preventive maintenance includes replacing air filters in order to promote adequate air flow. The refrigerant circuits should also be checked to confirm the refrigerant charge is within safe operating levels and to confirm the superheat and subcooling levels are within the acceptable standards. If any variation is detected, refrigerant levels should be adjusted. Additionally, evaporator and condenser coils should be cleaned if needed so they can absorb and reject heat properly. Another important step in preventive maintenance is to confirm that all units with economizers are operating properly and bringing in outside air to cool the store when applicable. Spring is the ideal time to have HVAC units serviced before the heat of the summer puts additional strain on equipment; however, preventive maintenance should be performed at least four times per year to keep equipment operating efficiently year-round.
Dennis Burke: Tune up the system(s) by cleaning coils, verifying proper operation and operating pressures.
Don Langston: A thorough inspection of each air conditioning unit should be done a minimum of 60 days prior to the start of the summer season. This inspection would include the washing of the condenser and evaporator coils, replacing belts and air filters, checking the overall operating efficiency of the unit, the refrigeration cycle, electrical components and air distribution.
Ron Prager: All HVAC units — with the exception of VAV boxes that do not use air filters — require a full preventive maintenance inspection prior to the start of the cooling season. At a minimum, the scope of the maintenance inspection should include the following:
• Replacement of all air filters with dated filters.
• Replacement of drive belts (minimum once annually).
• Full operational check of all stages of cooling and economizer.
• Visual inspection of contactor contact points, coils, disconnect switches, cabinets, etc.
• Confirmation of cleanliness of coils and correct refrigerant charge. Brushing down coils as required.
• Inspection and cleaning of condensate drainage components.
• Measurement of water and air temperatures in and out on water cooled and chilled water systems.
• Measurement of return air and discharge air temperatures.
• Lubrication of bearings that require lubrication.
• Measurement of current draw on all motors.
• Check programming of thermostat.
RFB: What are the most common maintenance calls you get regarding HVAC issues in the summertime?
Barraclough: If the unit has not been properly maintained, there are a number of issues that will arise. In most cases, equipment that is not maintained will have dirty filters, loose or cracked fan belts, dirty coils or an incorrect refrigerant charge. Any one of these issues can lead to unit failure and extensive repairs. This will also translate into loss of sales because customers will not want to shop in a hot store. The idea is to keep equipment working efficiently through preventive maintenance — this ensures customers will be comfortable and able to shop.
Burke: The most common maintenance calls we get are: “The store is hot”; “The A/C is leaking water”; and “How quickly can the repairs be performed?”
Langston: Restricted condensate drain lines and lack of cooling are the most common complaints.
Prager: Insufficient cooling, condensate leaks, and uneven temperatures throughout the store.
RFB: Everyone is trying to save money these days. How can retailers run their stores’ air conditioning more cost-effectively?
Barraclough: It is important to understand that the HVAC maintenance budget and the energy budget are interdependent. By investing in preventive maintenance, you will actually reduce your HVAC service, repair and energy costs because a well-maintained system requires fewer repairs and uses less energy. The converse is also true — if you reduce or eliminate preventive maintenance, you will see an increase in these costs as well as costs associated with equipment downtime. Many people don’t realize that preventive maintenance can help reduce costs because it seems counterintuitive; however, it is actually one of the most effective ways to reduce costs.
Burke: Make sure the coils are clean, make sure the system is tuned to optimum operating conditions, and make sure the building is properly sealed and insulated.
Langston: Have them serviced every 60 to 90 days. Make sure programmable thermostats are installed for each A/C unit. Make sure the proper building occupied and unoccupied times and temperatures are programmed for each day of the week. There is no value having a programmable thermostat set to 72 degrees 24 hours a day! I would recommend a temperature offset of 12 to 16 degrees between the occupied and unoccupied periods each day. It is also important to stagger the start times of each A/C unit by 10 to 15 minutes in the morning to minimize kW demand charges from your local utility company. Making this simple change can save a few hundred dollars a month.
Prager: Preventive maintenance is a must and will pay for itself.
If a retailer can reduce equipment run time, he will reduce both energy cost and the cost of repairs. This can be accomplished by maintaining equipment at top efficiency, raising cooling set points and lowering heating set points, replacing old inefficient equipment, and by the application of energy management systems.
Retailers need to mine their repair history to determine where they are spending the bulk of their HVAC dollars and then determine how to chip away at the issues that are of greatest cost. Tracking age of equipment against repair costs is a great way to start. Tracking cost of repairs per square foot and energy cost per square foot for same types of systems is another good starting point.
Some repairs can be deferred and others can’t. Retailers will need to partner with their vendors in order to decide what issues can wait.
Knowing the terms of the leases and the liabilities involved is a must for proper HVAC cost management. A retailer may save the cost of preventive maintenance for a year, only to learn that the landlord is holding the company responsible for replacement of the equipment because the retailer was in default because he didn’t live up to the terms of the lease with respect to HVAC equipment maintenance. Conversely, a lease may provide for landlord participation if equipment is replaced during the last 2 years of a lease.
RFB: HVAC is a huge user of energy. What is being done in the industry to make HVAC more energy-efficient and environmentally friendly?
Barraclough: Through the use of technology, contractors today are able to dramatically increase the efficiency of HVAC equipment by ensuring the system is running at peak performance. A few HVAC service providers are utilizing a handheld diagnostic tool, called the HVAC Service Assistant, to promote energy efficiency and optimize unit performance. The technology has the ability to confirm unit performance by acquiring key operating data and calculating the correct superheat and subcooling levels. The HVAC Service Assistant identifies and diagnoses any existing faults in the unit that is causing equipment to consume more energy than necessary. In one case study, the HVAC Service Assistant was used in a mall to help increase energy efficiency and resulted in 59,756 kWh annual savings and 31.6 reduction in peak demand.
Burke: (1) Use of larger (high efficiency) condensing coils; (2) installation of central station energy management temperature control sytems; and (3) installation of energy saving thermostats which start the HVAC equipment based upon outdoor conditions (temperature and humidity) as well as coordinate the HVAC equipment run time to the hours of building occupancy.
Langston: The EPA has mandated higher efficiency equipment. The new R-410A equipment is an incremental improvement in efficiency. New variable speed compressor and motor improvements are also driving incremental improvements. New service tools that provide data on operating efficiency, similar to the dynamometer for automobiles, are becoming more commonplace in tuning A/C units to operate to peak efficiency. Improvements to light building automation control systems are bringing down the costs and making networking and managing of single and multiple sites easier.
Prager: As everyone in the facilities industry knows, manufacturers are no longer going to be allowed to build equipment that utilizes R-22. All new equipment will use R-410A, which has a reduced impact on the ozone layer.
The trend over the past years has been for manufacturers to provide a choice of equipment efficiencies for commercial rooftop equipment. Most manufacturers can provide a standard efficiency unit or a high efficiency unit in all capacities. There has been competition between manufacturers to build the equipment with the highest efficiency, and therefore with the lowest operating cost.
We have recently seen manufacturers producing what I will call a “poor man’s EMS system.” These systems consist of communicating thermostats and digital control modules that can be used to control lighting, that interface with a server that allows display and human interface via Web pages. I believe that these systems will become extremely popular within the retail industry as the technology matures. The cost of installing, owning and operating an EMS system is dropping and utility rates will only rise in the future. Reduced payback periods will be the result.
RFB: What are the latest questions and concerns retailers may have regarding the government mandated phase-out of R-22 refrigerants? Is the retail industry ready?
Barraclough: In the short term, the R-22 phase-out will not have much of an impact on retailers with existing equipment that utilizes R-22. After 2010, chemical manufacturers may still produce R-22 to service existing equipment, but the production will be reduced by 65%. In addition, 2010 marks the date manufacturers are no longer allowed to make HVAC equipment using R-22. By 2015, production of R-22 will continue but be reduced to 90% of the 2010 production volume. Use of existing refrigerant, including refrigerant that has been recovered and recycled, will be allowed beyond 2020 to service existing systems, but chemical manufacturers will no longer be able to produce R-22 to service existing air conditioners and heat pumps. The retail industry should not be impacted as long as they select an air conditioning contractor that is certified in the use of the new refrigerant and that follows EPA guidelines to properly service equipment with R-22 refrigerant. It is important, however, that retailers start thinking about their long term replacement plan and replacing inventory with EPA-approved units.
Burke: (1) “When does this take effect?”; (2) “Do I have to change out my existing equipment?”; and (3) “How much is this going to cost our company?”
Langston: The HVAC manufacturers have to stop making equipment with R-22 by December 31, 2009. They can still sell R-22 equipment already manufactured after January 1, 2010. I would recommend reviewing capital requests for new equipment and replace what you can this year. The replacement of 5- to 25-ton equipment in the first half of 2010 with both R-22 and R-410A will be limited and could result in extended lead times. We have enough inventoried supply of R-22 until 2012. Beyond that, point prices could begin to rise steeply. However, several manufacturers have developed both intern and long term replacements for R-22 that should keep existing equipment operating for the next decade without disruption.
Prager: Retailers are concerned about the cost of repairs that require R-22 to be replaced or added to a system.
They are questioning the availability of sufficient quantities of R-22 to meet industry demands as limits are placed on how much new R-22 can be manufactured.
They are concerned about availability and cost of replacement parts, such as compressors for the hundreds of thousands of R-22 systems they currently own.
They are concerned about the increased costs involved in servicing new R-410A systems. These systems use components that are rated for higher pressures and are therefore more costly to manufacture.
With respect to readiness, the mandated phase-out of R-22 will mean increased cost of ownership to retailers. At this moment, I don’t believe there are many retailers ready to accept increased costs. It is more a question of the HVAC industry being ready to provide enough recycled R-22 to meet the service requirements of existing units for the next 15 to 20 years, and being willing and able to provide a sufficient quantity of replacement parts for R-22 units. |
