Staying One Step Away from HVAC Trouble

Part 1: HVAC Maintenance and Energy Savings

Part 2: HVAC Maintenance and Reliability and Longevity

HVAC Maintenance and Energy Savings

By James Piper, P.E.
March 2009

In spite of years of studies, demonstration programs, and published stories to the contrary, most facility organizations today still operate in a reactive mode. Though facility executives know that is far better to schedule maintenance activities using planned and predictive maintenance tools, most continue to spend the bulk of their resources operating reactively. The most common reasons cited for this is the lack of sufficient resources.

This approach to maintenance with respect to HVAC systems is particularly troubling given the role that HVAC systems play in today’s facilities. HVAC systems in typical commercial buildings are responsible for more than 40 percent of total energy use. Keeping HVAC systems running properly and at peak efficiency is the first step in managing facility energy use.

The importance of good HVAC system maintenance goes beyond just controlling energy use. Buildings today depend on properly operating systems for more than just people comfort. For example, most telecommunications systems have requirements for specific environmental conditions to operate properly. Temperatures and humidity levels that fall outside of this range can lead to interruption in services and even costly system failures. Sometimes the difference between keeping a business running and having to shut down is nothing more than proper HVAC system maintenance.

What Goes Wrong

In spite of all the supporting data and facility executives’ efforts, most organizations underfund maintenance. Reactive maintenance remains the norm, not the exception. Maintenance is deferred. Planned and predictive maintenance remain the exception. The most commonly cited reason for not performing routine and preventive maintenance on HVAC equipment is lack of resources. The C-suite rarely has facility experience and does not fully understand the need for maintenance. To many who establish and control budgets, maintenance is an overhead cost. Like other overhead costs, steps should be taken to reduce it. Reducing overhead costs increases profit margins. And like other overhead costs, the only impact of this reduction is reduced costs. Proper maintenance of HVAC systems requires careful planning and forward thinking, both of which become lost when maintenance is considered nothing more than an overhead expense.

Contributing to this belief is the unfortunate fact that HVAC systems are not the most noticeable components in a facility. Unlike highly visible items, such as carpet or lighting systems, most HVAC systems are out of sight and out of mind, until something goes wrong. And when something does go wrong, it is too late for maintenance to be performed efficiently. Maintenance at that point becomes reactive.

Reactive maintenance is the most costly way to maintain building HVAC systems. Organizations that have implemented comprehensive planned and predictive maintenance programs show dramatic decreases in maintenance costs. And when factors are included, such as extended equipment life, reduced energy use, less frequent system downtime, and decreased interruptions to building operations, organizations that have implemented comprehensive maintenance programs find that their total costs can be as much as 50 percent lower than the costs for those organizations that continue maintain equipment reactively.

While it is easy to blame those who control the budget, facility executives themselves are at least partially to blame. If facility executives are to receive the budgetary support necessary to carry out their mission, they must present their case in the terms that are best understood by budget managers. Simply saying that money is needed to overhaul or replace a chiller, particularly when the chiller is still running, is not enough. Facility executives should be able to demonstrate the consequences of ignoring HVAC system maintenance while identifying the real cost savings associated with comprehensive maintenance. Demonstrate that dollars spent on the maintenance of these systems will result in an improvement in the bottom line.

Location, location, location. The phrase is a real estate cliché. In maintenance budgeting, the key is documentation, documentation, documentation. Funds in organizations, particularly during economic downturns, are limited. Competition for those funds is intense. Other departments have pet projects that they are promoting. They are the competition. If facility executives want to level the playing field, they should make the case that investing money in HVAC maintenance will provide the organization a rate of return that is equal to or even greater than what others are promoting. And that requires documentation.

Properly maintaining HVAC systems provides a number of benefits that facility executives readily understand. Proper documentation of these benefits will help budget managers develop the same level of understanding.

Energy Savings

One of the easiest benefits to document is how HVAC maintenance affects energy efficiency. Facilities in which proper HVAC maintenance is completed will use at least 15 to 20 percent less energy than those where systems are allowed to deteriorate.

For example, consider the operation of a central building chiller. Building chillers typically are the single largest user of electricity in a facility. To keep them operating as efficiently as possible, maintenance tasks must be performed on a daily, weekly, monthly and annual basis. Let them lapse, and efficiency will decrease, increasing energy use.

Start with the chiller operating log. Work with the chiller manufacturer or a service company to translate the log data into an operating efficiency curve for the chiller. Develop a similar curve for what the efficiency of the chiller would be if all maintenance were performed at the recommended intervals. The difference between the two operating efficiencies can be translated into energy and cost savings. Due to the high energy use of the equipment, even small increases in efficiency will result in large savings.

While the energy savings estimates for chillers, boilers, and many other HVAC systems is straightforward, others savings estimates may not be. Consider outside air dampers. Air dampers require regular maintenance to respond properly to the temperature control system’s demand for ventilation air. If the damper linkage is out of adjustment, or if it sticks open, more ventilation air will be introduced than necessary, requiring the system to use more heating or cooling energy to condition that air.

Regular inspection, testing and maintenance of the damper will keep it operating properly, minimizing energy use. Document what needs to be done, how much it will cost, and what the cost would be for a stuck damper. Show how much a stuck open damper would cost in terms of energy use.

Comments

John Cockerill wrote re: HVAC Maintenance and Energy Savings
on 7/10/2009 12:04:55 PM

When it comes to adjustments, the avalability of accurate actionable data is the key. It also difficult to adjust everytrhing all at once over a 24 hour day 7 days a week without great expense and athletic ability. You have to consider the interruptions, flooded toiletrs and light bulb replacements that are needed now. So you can save a lot of time and wasted energy by truly automating as many features as possible and spending time checking periodically as you say. The answer is a combination of employing the reliable technology now, with a disciplined followup to make sure of everything.

BobVahey wrote re: HVAC Maintenance and Energy Savings
on 7/10/2009 11:54:07 AM

Wonderful! Yet another example of how common sense and time spent thinking about and understanding the dynamics of mechanical system operations and maintenance can be parlayed into a system of checks and routines. As a consequence. better performance and decreased costs are manifest. Nice!!!

Bernie Daily wrote re: HVAC Maintenance and Energy Savings
on 4/15/2009 7:02:43 AM

I loved the article. My little heart is pounding.
Here is the way I have been optimizing buildings since around 1984. I offer implementation either stand alone and hand written or through a partner web-based facilities management program.

Daily Operations Building Optimization Plan

Overview

Getting your arms around building energy consumption and the performance of equipment can be a simple and achievable process. The traditional power plant, as far back as the 1800’s, routinely logged the operation of each piece of equipment on a regular basis. Small problems in such an operation are found early and addressed before performance and reliability are compromised. Bringing this method to building operation has dramatic results. In some cases energy consumption and demand have been reduced by 40%. Frequent “off hour” trouble calls can quickly become the exception.
The Daily Operations Building Optimization Plan modernizes the permanently drafted log sheet of the past and makes it fully adaptable to the dynamics of your building.

Step 1: The Library

A library of various equipment types has been assembled on an Excel Spreadsheet. Each parameter of checking the equipment is listed to be copy/pasted to a log sheet. A block of data to check an Air Handling Unit with a heating and cooling coil will allow for the temperature entering and leaving as well as pressures. Particulars such as, the motor running, damper position, bearing noise, and even if local lighting is on, are included. All parameters can be edited and additional library entries can be created.

Step 2: The Route

A logical route through the building mechanical rooms and equipment spaces is established. The Route should be direct and not take more than 1 hour to 1 ½ hours to tour. Larger buildings may require a number of routes. A 500,000 square foot factory will generally require three routes. Each piece of equipment is listed in the order of its sequence in the route. Include small items as well as large. A single meter reading along the Route can provide great insight.

Step 3: Creating the Log

With the route established, a Log is created by copy/pasting the Library parameters for each piece of equipment in its sequence along the Route. The Log can be printed and inserted in a binder. Carrying three previous logs with the current one in the binder will help show an immediate history or trend. In some buildings local reading may be absent and available on a building management system. An insert allowing for later gathering of that data will make referencing easy. The Log is a worksheet, so encourage additional notes.

Step 4: Walking the Route

The frequency of walking the Route will depend on your budget and staffing availability. By keeping the Route at less than 1 ½ hours it may not encroach on other routines. The ideal in an active building is to walk the route Monday, Wednesday, and Friday. Monday will assure that any failure over the weekend will be found. Imagine a condensate leak in outside air stream that has built a block of ice that weighs 1,000 pounds. And no one knows when it started. The Friday walk through will find a potential weekend problem that could result into an “off hour” call in or unnoticed event leading to an emergency.
The Wednesday is a comfort and familiarity walk as well as inspection. The operator gets to know the operational sounds, smells, and basic rhythm. A change in sound can immediately alert the operator who is familiar with the normal conditions. A steam meter reading can alert the operator to an increase of 4,000 #/hour that may be as remote as a stuck back draft damper on an exhaust fan.
Your operator will have his thumb on the pulse of your building in about two weeks.

Step 5: A Second Pair of Eyes

During regular working hours the Log books will be available to a group leader or supervisor for review. Different people place priorities on operational aspects that may not have been obvious to another. Questions and discussion of the readings and operation of the equipment should be encouraged. Cross training can be aided by real examples. Routes can be traded or rotated. Many times an operator will take ownership of his Route area. Friendly competition may begin to demonstrate who has the best uptime or greatest energy reduction. Your building will be the ultimate winner.

Step 6: The Work List

Generate a work list from the Logs on a weekly basis. Initially the Logs will show lacking or inoperable gauges and thermometers as well as other items that will not allow a reading. All these will make the work list. A simple list of one line job descriptions on a clip board works well when the operators prioritize their own jobs. Building Maintenance Work Orders can be generated when appropriate. A list of about thirty jobs is very workable. Expect the easier ones to be picked up and completed first. It is not unusual to find four or five larger unpleasant jobs lingering. Those are good jobs for the supervisor to assign to two or more mechanics.

Step 7: Evolution

An Evolution of the building operation will begin with the initial steps. Those tasks of sensing device replacement will lead to a deeper questioning of the equipment operation. Replacing temperature sensors can show a low temperature differential of a unit or a system. A chilled water system may be circulating at only a small capacity of its design. You send out cold water and expect warmer water to return. This condition can exist for years. Imagine a company sending out product and expecting money in return. Red flags would wave if none or too little returned. The money spent on an inefficient building system cuts deeper into the budget as energy costs rise. The awareness of your building operation using the Daily Operations Building Optimization Plan will point out waste as quickly as a lack of cash flow at the accounting department. After six months of use most facilities will achieve dramatic success. Energy and demand costs will drop. Reliability will be high and repair costs will begin to drop. Trouble calls and emergencies will be greatly reduced.
Reduce energy consumption and reduce your carbon foot print. These steps are simple and achievable. A lot of technology is being developed as sustainable methods. The Daily Operations Building Optimization Plan is something you can do today. It is a sustainability effort with a payback.

If you have comments or questions you can email DailyOps@frontiernet.net.

Thank you, Bernie

kyleadamo wrote re: HVAC Maintenance and Energy Savings
on 4/14/2009 9:50:11 PM

Great article. I'm currently working on putting together a compelling ROI for top notch PM planning based on actual maintenance data from our cmms users. This has been most useful.

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