Stop me if you’ve heard this one before:
Based on a heat complaint from a store manager, a truck is rolled, but no problems are found with the HVAC units. Just a hot store manager.
Or this one:
There is a problem. But the technician checks out 2 units that are functioning fine before discovering, an hour later, that something appears to be wrong with the 3rd unit. It then takes another 30 minutes to diagnose and fix the problem.
There has to be a better way and, good news: there is. Many companies have deployed systems to help them avoid these situations – by moving to Intelligent Dispatch. With the cooling season underway, this is the perfect time to begin investigating options for achieving such a process.
What is Intelligent Dispatch?
Intelligent Dispatch involves leveraging sufficient data intelligence before dispatching a technician to know whether there is a problem, where that problem lies, and the most likely cause (or causes) of the problem.
Getting to Intelligent Dispatch requires the ability to “see” equipment remotely. (Let’s stick with HVAC equipment, although the concept applies to a broader range of equipment as well.) At the simplest level, having Internet-connected thermostats allows an organization to know exactly what the temperature is in a facility when a hot/cold complaint is received. Unless there is a policy to automatically dispatch a technician, this can avoid that truck roll when the temperature is, in fact, in the acceptable comfort range.
If there appears to be a problem, this type of system may help pinpoint it, since the temperature readings will provide an indication of which HVAC unit is experiencing a problem. If the system is able to report both the set point and the actual temperature reached by each unit, you have even more data with which to isolate the problem. Of course, where multiple units are heating and cooling the same space and only 1 is failing, it is possible that more than one of them will have difficulty hitting their set points, making it harder to know a priori which HVAC unit is experiencing the problem.
Systems that also monitor the energy usage of each HVAC unit provide significantly more information to assist with Intelligent Dispatch. Specifically, the energy use pattern will identify if a unit is working at all, and whether it is operating as expected. This allows the dispatch call to direct the tech to the specific unit s/he should work on.
Can Problems be Diagnosed Remotely?
Asset and energy management systems are getting smarter all the time about helping facility teams diagnose problems in advance – even performing automated diagnoses. This provides specific direction to the technician dispatched to address the problem, further reducing the time of the service call.
Here are a couple of examples:
In the first example, the system-generated graph shows 2 issues; a low “Delta T” (the difference between the Supply and Return temperatures) of only 5°F, and an unusual “shark tooth” usage pattern.
The Delta T was well below the expected 15° – 25° range, while the shark tooth pattern was indicative of a problem. The system flagged this as the probable sign of a condenser fan failure. The tech was dispatched with this information, which turned out to indeed be the cause, resulting in a much faster than average RTU repair call.
The second example shows a different pattern – “short cycling” – and a different way in which this type of data can be extremely helpful. In this case, the unit is turning on and off rapidly, often never actually reaching its set point. Short cycling can be caused by a variety of factors, including a low refrigerant level (or a high level for that matter), a dirty condenser, and high condenser pressure. A unit can be short cycling and still hit its set point – at least for some period of time – so there may never have been a hot-cold call. In this case, the benefit may come from warding off a problem downstream by having identified that the unit is not operating properly, and arming the technician with the knowledge of what to look for.
How else can Intelligent Dispatch help?
In the first example, had this problem not been caught, the unit would likely have continued to operate, but very inefficiently. The company estimated that this repair saved them about $750 in energy costs for the summer months.
When a unit short cycles, it uses more energy than it needs to. Moreover, if unchecked for a considerable period of time, this behavior will shorten equipment life.
These impacts are not limited to these examples; they are very common across a wide range of equipment problems. A system that identifies equipment problems enables proactive service calls as opposed to the more costly reactive calls – another benefit of Intelligent Dispatch.
According to PRSM, reactive service calls after equipment breaks are, on average, three times as expensive as proactive calls – costing around $400 more per call on average. Therefore, having the data to schedule service before a unit fails can drive down repair and maintenance costs in the long term. Moreover, system failures can have impacts on customers and staff that go well beyond the cost of the service call itself, so being able to make Intelligent Dispatch decisions can have far reaching effects.
Delivering the Benefits of Intelligent Dispatch
Being able to achieve Intelligent Dispatch requires an energy management system that can both capture and analyze data about equipment performance, and make intelligent assessments about what the data is saying. The good news is that cost-effective systems that can accomplish this are becoming more widely available – and the systems continue to get more intelligent.
One word of caution; these systems will, at times, deliver false positives, or alerts to problems that are not really problems. If this happens to any large extent and the alerts are used to generate work orders, the savings associated with Intelligent Dispatch could be outweighed by the costs of unnecessary truck rolls. It is important to work closely with the system vendor to minimize the number of false positives, and make sure the system is well calibrated before it is used to automatically trigger work orders. Some vendors are working on enhanced algorithms to minimize false positives. If the system can maintain a robust overall “batting average”, it should be able to deliver significant benefits from Intelligent Dispatch.
In the end, Intelligent Dispatch can be considered a key step on the road to what is sometimes described as the “holy grail” of facility management: condition-based maintenance. Condition-based maintenance (CBM) is a strategy that involves monitoring the actual condition of an asset to decide what maintenance needs to be done. CBM dictates that maintenance should only be performed when certain indicators show signs of decreasing performance or upcoming failure. While most facilities organizations are reluctant to move away from scheduled maintenance, a positive experience with Intelligent Dispatch over a period of time may be what is needed to move to a CBM-based approach to equipment maintenance.