September 2010

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Control issues
Controls and building management systems have for too long been relegated to the final stages of building commissioning. And they have remained largely misunderstood by most building stakeholders, to the detriment of building performance and overall energy efficiency. But the industry is set to take control, as Sean McGowan reports.

 

This article originally appeared in the August 2010 issue of Ecolibrium, the official journal of AIRAH, and is reprinted with permission.

 

Last month, following the receipt of funding from the AusIndustry Green Building Fund, AIRAH announced its intention to produce two manuals seen as critical to the efficient operation of Australia’s existing building stock.

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Both manuals, the Australian Best Practice Guideline for Controls (DA28) and the Australian Best Practice Guideline for Commissioning and Retro-commissioning (DA27) will be the first of their kind in Australia.

“It is widely recognised that one of the major areas of improvements to be made in the commercial built environment contributing to a reduction of energy, water and greenhouse emissions is through commissioning and retro-commissioning initiatives, and through good-practice design, installation, calibration, programming and operation of controls systems,” says AIRAH CEO Phil Wilkinson, M.AIRAH.

“By producing new guidelines for controls, and commissioning and retro-commissioning, the Institute will be addressing subject matter for which there is a pressing need,” he says, adding that AIRAH, recognising the importance of addressing these issues, will match the Green Building Fund contribution dollar for dollar.

In light of this announcement, Ecolibrium put together its own small panel of industry representatives to look at the issues the Controls Subject Matter Expert Working Group will be considering between now and the Guidelines’ targeted completion date of May next year.

Included in the discussion was group chair Jon Clarke, M.AIRAH. Clarke is associate, controls and integration, for Norman Disney & Young’s Sydney operation.

Also part of our panel were Mark Mitchell, general manager (projects) for A.G. Coombs, and Nirosha Munasinghe, product development manager for Open General.

Ecolibrium: Why is the Australian Best Practice Guideline for Controls needed?

Mitchell: Building controls are now more important than ever. It comes down to the difference between am HVAC system that simply works and a system that works while using the minimum amount of energy, and controls are at the heart of that difference. An Australian best practice guideline will help achieve best practice through the establishment of technical, functional and commissioning standards for performance outcomes.

Clarke: The building management system (BMS) controls industry covers a broad section of disciplines, so understanding the fundamentals of mechanical, electrical and information technology is paramount to getting the best performance out of a building in terms of sustainability and comfort.

This guide will hopefully help bridge the gap between consultants, controls engineers and building operators.

Munasinghe: It is needed to address the inconsistencies of building control strategies from building to building. Also, it needs to address the lack of governance in controls from the specification provided by the consultants to the end results after the building is commissioned.

Ecolibrium: It seems then that the controls sector has suffered from segmentation. Your thoughts?

Mitchell: The controls sector has typically been organised around a small number of proprietary vendors, and had only limited opportunity to benefit from knowledge sharing and continuous improvement towards industry best practice. Industry has previously sought to address this through facility or project-specific design specifications, which are often too aspirational, or paradoxically often outdated.

Ecolibrium: Jonathon, you also believe the skills shortage is having an impact?

Clarke: There are good product engineers that understand how to write the controls code inside out. There are also good mechanical engineers who understand the requirements of a building to maintain conditions, but getting an engineer who understands both intimately is a rare occurrence. Generally, specifications fall short of the detail required to accurately write the controls code. In a very competitive industry, the controls suppliers only provide the bare minimum to meet the intent of the specification. On more than one occasion I have seen controls code barely resemble the specification at all.

Munasinghe: I’ve seen many personnel who are involved in programming BMS systems that do not have the knowledge or the expertise to complete the tasks. Programs are being copied from old projects which do not suit the current project.

Control Solutions, Inc Ecolibrium: Are controls still considered something of a “black art” then?

Clarke: The short answer to that is yes, unfortunately they are. This is mainly due to a combination of lack of understanding from the building operator’s point of view, and that most systems hide the control code from the operator and have poor functional descriptions.

I have often had building operators tell me that the controls guy has attended the site to fix a problem, but no one knows what he has done or understands the report, if there is one.

Mitchell: Controls are perceived to be less tangible and transparent than other HVAC elements within a building; from a client perspective this often leads to incomplete understanding. In recent years this has been compounded with the increased reliance on network (ITC) knowledge and the integration with security system packages.

Munasinghe: The good news is that controls software is moving towards a web environment, and integrating with IT networks that are accessible to a wide audience. Therefore, more and more people are starting to be aware of the BMS and starting to interact with it, especially with energy management data. However, there does need to be continuous improvement in BMS software to report different levels of data to different audiences.

Mitchell: There’s nothing wrong with controls being a “black” box – this is essential for technology vendors’ profitability and subsequent development of new technologies. However, they shouldn’t and can’t continue to be a black art. We do need to demystify controls and make the black box more translucent. Everybody around the black box, from consultants, designers and builders, to contractors, property managers, maintainers and owners, all need to understand how it works, what it does and what its attributes, issues and limitations are.

Ecolibrium: How linked in is the commissioning process?

Clarke: BMS commissioning will continue to be a bone of contention until the construction industry recognises that it’s not just about blowing air!

Time is always compressed, and the BMS is the last to get finished as it is dependent upon the building services being complete. These days BMS systems are high-tech and closely aligned with IT systems, but are still being procured by mechanical contractors.

Mitchell: It is one of the single biggest issues facing our industry at present. Forces such as reduced construction programs, limited commissioning durations and a lack of expert personnel are collectively leading to poorly commissioned systems.

This, however, is the new project delivery status quo, so as an industry we need to better adapt.

Munasinghe: From a project point of view, lack of proper commissioning and a mismatch in the end results and specification is a major issue. As long as the air conditioning is working fine there are no complaints from the tenant, therefore other issues of building management are not addressed.

There are many cases that I have seen where after the end of the commissioning phase, the BMS does not exactly function to the original specification. The controls company is usually the last to access a building, and due to the time pressure, the controls normally do the minimum requirements. The typical optimising strategies, alarming and logging is left out for another time and in most cases these are incomplete.

Ecolibrium: What are some of the solutions to this issue?

Mitchell: Earlier installation completion, factory software application testing and a focus on all aspects of commissioning, including better commissioning management and coordination, improved integration of controls commissioning, with building systems commissioning to achieve performance outcomes, and specific things like field wiring pre-commissioning, functionality testing, front-end-to-field-device testing and seasonality testing.

Clarke: When commissioning time is running out flooding the floor with labour is not the answer. The commissioning process should be considered during the design, and engaging the controls supplier as early as possible helps to mitigate some of the issues. Commissioning and final tuning should also carry on during building occupancy in conjunction with operator training. “Soft landings” is the correct approach.

Ecolibrium: Traditionally, building owners haven’t employed anyone to check that the building is operating correctly from a controls/BMS point of view. Is this changing?

Clarke: Building owners are becoming more involved with their asset performance, especially with a focus on energy, and the KPIs of the building operators. This is a good thing, as it raises the awareness of how important the BMS is.

Mitchell: Our considerable experience has proved the benefit of a client-representative “superintendent” role to provide surety of the controls commissioning outcome. However, the controls sector should not be reliant on such externals watchdogs, and take a position of increased ownership of the intended client outcome. Further, this should be better integrated with the transition to operation and longer term tuning and maintenance of the system.

Munasinghe: It needs to be a proactive process. BMSs are starting to gather a lot of data and needs to use this data as intelligence to start predicting events. It also needs to give more information back to the tenant for them to be more involved with the BMS systems.

For example, most systems have fancy energy dashboards reporting energy usage, which are generally seen only by the facility management. They should be extended to be more educational, and be displayed at foyers and receptions for the tenant to see the critical data of the building. The more data tenants see, it will encourage them to be part of the building management process and be more involved in reducing energy.

Reliable Controls Ecolibrium: Nirosha, being closely involved with hardware and software, what are some of the issues there?

Munasinghe: From a market point of view there are less and less small/medium-type controls hardware and software companies due to mergers and acquisitions. Larger players dominate the market, and most of them are heading towards having limited distribution channels, with the preference of completing projects by the controls company itself. This is leaving many integrators without the controls product to process for the end client, and larger controls manufacturers charging premium prices from the client.

Also from a products point of view, most controls manufacturers are transforming their product range to open systems, with BACnet, LonWorks and web technologies. To do this in rapid time, they are adding a layer into their current proprietary systems to open up the systems. But this adds extra hardware such as gateways and extra software layers, introducing many applications to complete the tasks.

This is starting to confuse the end user about what is open and what isn’t, and also the workflow in the software to complete the task. This needs to be addressed with better education of both the system integrators and end users.

Ecolibrium: And what are some of the latest innovations?

Munasinghe: As mentioned earlier, software is moving away from a desktop environment to web-based systems that have access to a wider audience. Also, there is improvement in user graphics, in particular with energy reporting. There are more dynamic data displayed in 3D graphics for more realistic views of the building to the user.

The input/output of the physical hardware has not changed immensely over the decade but the devices are smarter. The devices are integrating more with other devices due to open system protocols.

Ecolibrium: Does the battle between BACnet and LonWorks still exist, or has one protocol taken over?

Munasinghe: Both exist in the market but generally they have found their own markets without large competition. In Australia, BACnet is the preferred protocol in most new building and retrofit specifications, but in Europe there are many LonWorks devices, in particularly in the area of street light control using power line communications. In North America both protocols are present but my feeling is that BACnet is starting to become the preferred protocol.

Mitchell: We have recently seen an increased prevalence of BACnet systems in the market. However, we see both technologies comparable in terms of practice performance. From a client perspective, the bigger issue here is that while technically possible, true, open, multi-vendor control systems do not in reality exist, despite the intentions of such interoperability standards.

Clarke: The trouble is there is still a misconception of what these protocols can provide. Having a BACnet or LonWorks system still requires a level of service from the system manufacturer. I have had a number of discussions with clients who were under the impression that if they chose an open system, they could go to any provider for service and maintenance, but this is simply not the case.

Ecolibrium: Are controls and BMS still the most obvious low-hanging fruit in existing, poor-performing buildings?

Clarke: The BMS is the first place to look for building performance information. It will certainly provide information that can indicate where problems would be. Low-hanging fruit usually points to incorrect time schedules and set-points.

Mitchell: We are regularly asked by facility owners and operators to review their control systems for improved performance outcomes. Usually controls haven’t been set up as a tuning tool, so the first challenge is to get headend interfaces to the point where they can be used to optimise the building’s systems.

We are actively involved in the optimisation of energy systems in a wide range of buildings around Australia, and this usually results in energy efficiency improvements of between half and one and half stars, with some exceptional outcomes in excess of that. These relatively low-cost enhancements often also result in tangible improvements to occupant comfort.

Jon Clarke
Associate, Controls and Integration
Norman Disney & Young (Sydney)

Mark Mitchell
General Manager
A.G. Coombs Pty Ltd (Projects)

Nirosha Munasinghe
Product Development Manager
Open General

Ecolibrium: Further to that, what are some of the easy things that can be done with controls to have building systems perform better?

Clarke: Getting them to operate as they were intended would be a good start! Time schedules, optimum start and economy cycles operating correctly will have direct impact on building performance. VAV systems with fixed static pressure set-points are generally wasteful of energy.

Mitchell: Other examples include the selection and implementation of the correct control strategies for the application, comprehensive system commissioning by skilled technical resources, the improved configuration of control systems as a true diagnostic and optimisation tool, and correct seasonal building tuning, for 12 months and beyond.

Munasinghe: Keep it simple. There are many specifications with many optimising control algorithms that do not behave in reality as in theory, or the engineer programming the system lacks the knowledge to program the system, which is preventing simple control strategies from performing. Also, if optimising algorithms are implemented, it has to be carefully tested and retuned throughout the lifecycle of the building.

Ecolibrium: Is it as simple as bad controls, bad building?

Clarke: Optimum building performance is a fine balance between maintaining conditions and minimum energy draw. The control system has the tools to create this balance, and is therefore instrumental to the performance.

Mitchell: Just as well-configured controls can be used to extract significant energy efficiency improvements out of building systems, poorly configured and commissioned control systems can be severely detrimental to building performance, including in the areas of occupant comfort, environmental outcomes and operator confidence.

The concept of “bad controls” is a slight misnomer, as most systems offer similar fundamental technological performance. So it tends to be the extent to which these systems are correctly configured and commissioned that should be regarded as “good” or “bad”, which is ultimately correctable.

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