Energy Management Systems: Maximizing Energy Savings (Text Version)
Courtney: Hello everyone and welcome to the Department of Energy's Technical Assistance Program webinar series. Today's webinar is Energy Management Systems Maximizing Energy Savings, and our presenter today is Sara Lisauskas from ICS International. So before we jump in today's presentation I'd like to take a few moments to describe the DOE Technical Assistance Program, or TAP. And TAP is managed by a team in DOE's Weatherization and Intergovernmental Program, the Office of Energy Efficiency and Renewable Energy.
The Department of Energy's Technical Assistance Program provides state, local, and tribal officials the tools and resources needed to implement successful and sustainable clean energy programs. This effort is aimed at accelerating the implementation of Recovery Act projects and programs, improving their performance, increasing their return on sustainability and Recovery Act investments, and building protracted clean energy capacity at the state, local, and tribal levels.
From one on one assistance to an extensive online resource library to facilitation of peer exchange of best practices and lessons learned, TAP offers a wide range of resources to serve the needs of state, local, and tribal officials and their staff. These Technical Assistance Providers can provide short term, unbiased expertise in energy efficiency and renewable energy technologies, program design and implementation, financing, performance contracting, state and local capacity building, and in addition to providing one on one assistance, we're available to work with grantees at no cost to facilitate peer to peer matching workshops and training.
We also encourage you to utilize the TAP blog, a platform that allows states, cities, counties, and tribes to connect with technical and program experts and share best practices. The blog is frequently updated with energy efficiency or renewable energy related posts. We encourage you to utilize the blog to ask questions of our topical experts, share your success stories, best practices, or lessons learned and interact with your peers.
Finally, we encourage you to make a request for direct technical assistance. And you can do this online on the Technical Assistance Center. Once a request has been submitted, it will be evaluated to determine the level and type of assistance TAP will provide. And with that we'll go to today's webinar, so Sara you're up.
Sara Lisauskas: Thank you. Before I get started I also wanted to note that all attendees are muted for the conference call, and if you have questions you can submit them in the "Questions" window and we'll answer them all at the end of the presentation. So as Courtney mentioned, my name's Sara Lisauskas. I work for ICS International on a number of projects focused on energy efficiency in commercial and institutional buildings. Energy management systems have always been a particular interest of mine, so I'm excited to talk to you all today about this topic.
Before joining ICS I worked as the Energy Manager for BJ's Wholesale Club. And if any of you are not familiar with BJ's, it's a warehouse club like a Costco or Sam's, and operates over 100 locations in the Eastern United States. While I was there I was involved in implementing more aggressive settings for lighting schedules, HVAC set points, and refrigeration controls. That resulted in significant savings for the company.
Since I've been with ICS, I've conducted energy audits for a large number of commercial and institutional facilities, and when I do I'm always particularly interested in finding the low cost savings opportunities that are available through optimizing energy management systems. I also invited one of my colleagues at ICS to join us for this presentation. Richard Kline just joined ICS in the last couple months, but has over 25 years of experience in the energy field as a consultant. His area of expertise focuses on advising government, commercial, and industrial clients on enhanced operations and maintenance modifications to improve operating efficiency of their buildings. So after I go through the presentation today, we can draw on our combined experience to hopefully answer any questions you may have.
The first slide describes the goals for today's webinar. The intent of this webinar series, as described in the introduction today, is to provide assistance to EECBG and SEP grantees to use funding quickly and effectively. So with that in mind there are three main audiences for this presentation: those of you that are installing a new energy management system with grant funding and want to do the best job you can with the installation. Those of you that are pursuing other energy efficiency retrofits like HVAC lighting, and should pay attention to how the new systems and draft an existing management system. And those of you that have some extra money potentially left over after you've pursued projects. You can use that money to improve upon an existing energy management system.
The agenda for today is presented on this slide. As a framework for the presentation, we'll start off with some of my basic principles for energy savings. Then I'll provide an overview of what an energy management system is and what its capabilities are. The majority of the presentation will review what I'm calling the Top Ten Control Strategies for Government Buildings. We'll spend some time discussing how to optimize an existing energy management system. And finally we'll share some resources that can be very helpful as you try to install or optimize an energy management system in your facility.
So this slide presents my basic rules for energy savings. The on the slide are not particularly complicated, but I think they can be very helpful. Based on the registration list for this webinar, it seems like there are a mix of technical and non-technical people participating in the call today. If you're not technical, these rules can help you ask the right questions of your facility staff. And if you are more of a technical person, these rules can help put a framework around how you think about your responsibilities with respect to energy efficiency.
I use these rules every time I do an energy audit; for each piece of equipment in a facility I think about each of the three rules. So the first rule is to use equipment only when you need it. Lights and HVAC equipment can often be on when they don't need to be; when no one's in the building, or no one is in a particular area of a building. So the easiest way to save energy is to turn equipment off when you don't need it.
The second rule is to use only as much as you need. It's not uncommon to see light levels that are unnecessarily high, base temperatures that are too warm in the winter or too cool in the summer or more fresh air provided to a space than is necessary. So you can choose set points that just the right amount of light or space conditioning that's provided to the building.
Then the third rule's about doing the necessary job as efficiently as possible. Which means installing lighting that delivers the most luminance to watts, or heating and cooling systems with the highest rate of efficiency. I think the third rule is important, and many of you are probably spending money on upgrading equipment to improve efficiency right now; however I think sometimes people place a little too much emphasis on installing efficient equipment and not enough emphasis on operating equipment in an efficient way.
So the first rule as above can often deliver greater energy savings at a lower cost. And if you plan to improve the operations of your facilities following rules 1 and 2, it's possible to do so using manual controls; however, the best way to optimize savings is by using energy management systems. So the focus of our presentation today is about maximizing savings using the 1 and 2 using energy management systems.
This slide provides some basics on energy management systems. A simple definition of an EMS is a system to control and monitor energy consuming devices, which may include heating and cooling equipment, fans, pumps, dampers, and lighting. Energy management systems can also be used to control refrigeration equipment, industrial processes, or other systems. But we'll focus on HVAC and lighting in the presentation today since they are the most relevant for government facilities.
Generally an EMS consists of three necessary elements: sensors will measure things like temperature, pressure, and light levels which are used to initiate responses by the system. Controllers will compare a signal received from a censor to a desired set point, and set out a signal to a control device for action. And then controlled devices are the equipment that receives the signals from the controllers, such as a fan, a pump, a damper, light switch, etc. In larger buildings and more complicated systems there's usually also a computer that provides a user interface that pulls all the information together for the building operator. And energy management systems can also be known as building management systems, or building automation systems, or energy management control systems. So there's several names out there.
Energy management systems have evolved in complexity over time. The most basic form of energy management consists of a simple time clock and thermostat. And in fact these systems are still the best choice of control in certain buildings today. Early centralized systems used pneumatic controls, and some of the systems can still be found in older buildings. And new energy management systems use direct digital control or DDC. DDC systems can use proprietary software, or they can utilize open protocol standards that allows components from different systems to work together.
The building operators can use an energy management system for different purposes. The main purpose is generally to ensure occupant comfort. Beyond that, systems can be used to operate equipment properly, insure proper maintenance, maintain safety, and of course to generate energy savings. Additionally, energy management systems can be used for non-energy related tasks such as security and fire systems as well.
This slide outlines the basic capabilities associated with energy management systems. The first two are the most important for energy savings. Energy management systems can manage the length of time that equipment uses energy, usually with very flexible scheduling options. Users can often configure multiple start and stop times for each piece of equipment for each day of the week. And exceptions can be programmed for holidays or other changes to technical operations.
Energy management systems can also manage the demand or the need for energy using set points for various sensors in the system, including space temperatures, pressure, humidity, flow rate, light levels, carbon dioxide, etc. Monitoring and trending can also be used to generate energy savings, but a little bit more indirectly. Energy management systems have the ability to track the space condition as monitored by the sensors, or the status of the equipment operation. This information can then be used to understand how the equipment is operating, and then come up with strategies to improve that operation.
Alarms are another feature that can be used to identify energy savings opportunities, but are generally focused or associated more with maintenance and safety. The alarm function will report critical information to building operators such as equipment failures, or values for sensors that are out of range such as base temperatures that are too high or too low. When using alarms it's important to set them carefully so you only receive alarms when really necessary. If there's too many alarms coming in, then it gets easier for operators to consider them a nuisance and ignore them.
Safety's finally are related to alarms in that they occur when equipment is not operating as it should be; however safety's go a step further and automatically initiate a control sequence to protect the equipment or the occupants in the building. In the real estate industry you always hear this phrase, "Location, location, location." I think for energy management systems the key is "Execution, execution, execution." You need to make sure you're doing things right. Energy management systems can have extremely sophisticated functionality, but they're rarely used to their full potential.
There are a number of reasons for this including poor planning, untrained operators, and lack of maintenance. This slide includes a few recommendations to make sure that you get the most out of your investment and that energy management system. First a good idea is to establish a team to either determine plans for installing a new EMS or identify upgrades to control strategies for an existing system. It's important to have representatives from your maintenance staff, your building occupants, and your senior management to have all perspectives represented.
Next it's important to have documentation available on how the energy management system is supposed to operate. It's very surprising how often this documentation does not exist. It can include user manuals on how to operate the software, drawings showing control hardware, points lists showing all the sensors and the control points in the system, and proper sequences of operation for the energy using equipment. Without this it's really impossible for building managers to understand and maintain equipment as it was intended to operate.
It's also important to have a standard operating procedure for the EMS, including who's responsible for maintaining set points and schedules, and responding to alarms. If there are multiple people involved in using the system it's especially important to make sure everybody's on the same page. Any staff involved with operating the EMS should be well trained on the EMS hardware and software, as well as the proper control sequencing for the building. And any staff involved in operating the EMS should also make sure to communicate any changes that are made to the set points or schedules and incorporate them in the documentation.
When installing a new EMS, commissioning is recommended to make sure that the system is functioning properly following installation. Then over time it's common for set points and schedules to change, so a service contract is recommended to regularly check on the EMS operation. And the contract should include maintenance of the equipment, as well as review of the sequences of operation to ensure that your desired energy savings persist.
And finally I would recommend don't making the system too complicated. Some building managers can handle very complex control strategies and will use them to their full potential. But others often end up paying for additional equipment and programming that never gets used because no one understands it. So know what your building and your facility managers can handle and then plan accordingly.
So now I'm going to go through what I'm calling my Top Ten Control Strategies for Government Buildings. Every building does have different equipment and considerations, so how you employ these strategies in your facilities may vary, and to what you'll generate savings may vary. But the general concepts should be appropriate in most facilities. And I didn't rank them the top ten in terms of the savings they would generate; but instead followed a sequence based on the rules for energy savings that I discussed earlier. I'll start with HVAC systems and then to get to lighting; and then for each piece of equipment, we'll think about when it's appropriate to use it only when you need it or turn it off. And when it's appropriate to use only as much as you need or turn it down.
And in some cases these strategies might be new to you; in other cases you may be utilizing these strategies in your buildings already. But even if you're already using the strategies, think about whether you're using them to their full potential or if you could be squeezing some more energy savings out by tweaking your schedules or set points. Also you may be able to use some variation of the suggested strategies to come up with your own top ten opportunities for your buildings.
The first control strategy is night set up or set back. With this strategy, the HAVC equipment is used only when it's needed. Equipment is turned off at night as much as possible, using set points for the heating systems that are reduced at night in the winter; and set points for the cooling systems that are increased at night in the summer. Set points are chosen such that the equipment can essentially be turned off except when extreme temperatures are reached. The EMS can control not just the heating and cooling equipment, but also the fans for ventilation.
And equipment can be controlled based on a simple time schedule or you could also use a more complex control strategy called Optimum Start/Stop. In this case the EMS determines the right time to start up and shut down a system based on an algorithm involving the outdoor temperature and the indoor temperature. I've seen some buildings that weren't scheduling equipment off at all at night and were able to achieve huge savings from night set back. Another case of buildings were using night set back, but were able to generate additional savings by shutting down equipment a little bit earlier or turning it on a little bit later in the morning.
_________ scheduling is another opportunity to use HVAC equipment only when you need it. It allows equipment to stay off when a particular area of the building's not in use. For example, if only one portion of a building's occupied, such as the gym in a school, on weekends or a meeting room in City Hall in the evenings, only the equipment in that area needs to be on, and the rest of the building can be shut down. This is accomplished by using different schedules to control different zones in the building if there are long hours or certain ____ are unoccupied. But the ability to utilize this strategy will depend on the configuration of your HVAC system.
Yet another opportunity to use HVAC equipment only when you need it is to have controls in place to prevent simultaneous heating and cooling. This strategy reduces the heating and cooling of the same air, which is the worst kind of energy waste. There are a couple different ways to accomplish this. First it's important to maintain a wide bed band, which is the separation between your heating temperature set point and your cooling temperature set point. The way the bed band affects your heating and cooling controls will be different depending on your HVAC configuration.
In an office building for example, with the variable air volume system with electric re-heat, simultaneous heating and cooling can occur if you're frequently running the chiller to satisfy the needs of some occupants while using re-heat to satisfy other occupants. If the bed band between your heating and your cooling set points is wider, then this is less likely to occur. Another strategy is to use - is to lock out heating and cooling systems at appropriate air temperatures. In particular it's important to pay attention to re-heat and electric baseboard heat. There should be an outdoor air temperature at which you know that it's warm enough outside that you don't need your electric re-heat or your electric baseboard heat any longer. If it's locked out, you employ the possibility that the internal base temperatures might inadvertently trigger the heat on in summer months.
These aren't the only strategies to limit simultaneous heating and cooling, but they are two of the more common ones. I would recommend doing some investigation to determine whether there's simultaneous heating and cooling occurring your building, and determine the best way to keep it from happening.
The example at the bottom of the slide shows some potential savings for just five kilowatts of electric heat, which could be from a small baseboard heater or a heater in a VAV system. It can cost an extra thousand dollars to operate that heat all year long. If it's possible to keep multiple heaters off by reducing the cooling supply to the building, significant savings are possible.
With this next strategy we're moving on to the next category of opportunities. So instead of trying to turn the HVAC system off, we're trying to use only as much HVAC energy as we need. In this case we're talking about cooling. Economizers, which are also known as free cooling, reduce the need for mechanical cooling. So when cooling is required in a building but the outside air temperatures are low, the dampers are opened and outside air is brought directly in to the safe to satisfy cooling needs.
In conditions where you're calling for cooling when outside temperatures are low are most likely to occur in buildings with high internal loads. So generally office buildings with high internal loads represent the best application for economizers. They can be controlled based on temperature, or more effectively based on control.
Resets are another strategy to use only as much heating and cooling energy as you need. Reset strategies will adjust the temperature or the volume of air or water that is supplied to a building based on the demand. Resets can be used in a number of different applications; one example of a reset strategy is for a hot water heating system. When the heating load is low if the weather is relatively mild, it's not necessary to distribute hot water throughout the building as the maximum supply temperature. Reset control will reduce the hot water temperature under these conditions with an algorithm that may be based on the outdoor air temperature, or even more accurately on the difference between the supply and return water temperate gets lower.
A few other opportunities to use reset are included at the bottom of the slide. Reset chiller supply water. Or supply air temperature in a VAV system can operate similarly to the hot water supply reset example, except it's based on a low cooling load instead of a low heating load. You can also reset the van pressure in a VAV system based on load, or the entering water temperature to increase chiller efficiency.
With all resets it's important to pay attention to interactions with other energy savings control strategies by adjusting the distribution temperature for a heating and cooling system so it's less extreme. It might result in a call for more supply water or more supply air, which increases the need for pump energy or fan energy. So proper programming of your energy management system can insure that the right combination of control strategies are being used to minimize your total energy consumption. When used successfully, reset strategies can save 5-15 percent on heating and cooling energy.
Similar to the previous example of staging the operation of boilers and chillers of the strategy use only as much heating and cooling energy as is needed. Using multiple boilers or chillers to meet a buildings heating and cooling can be more efficient than using a single piece of equipment, as long as the equipment is controlled in a way that maximizes energy efficiency.
For boilers, mingle to minimize partial loading since boilers operate more efficiently when they're fully loaded. So the system will only turn on as many boilers as is needed. If there's different types of boilers in the same plant, a control sequence can also give preference to the most efficient boiler.
Chiller optimization is a little more complex. Chillers can operate efficiently a part load, so the maximum efficiency can be achieved by comparing the part load efficiencies and the capacities of all the chillers in a plant, and determining the most efficient mix of equipment to operate. In both of these cases the optimization strategies can also take in to account the reset strategies for the output parameters which we just discussed in the previous slide.
Demand controlled ventilation is another strategy to use only as much as you need. In this case the goal is to provide only as much fresh air as you need. By minimizing the amount of unconditioned outside air provided to the HVAC system, the energy required to heat or cool that outside air is reduced.
Similar to they're generally based on 62.1, which requires a certain amount of fresh air usually expressed in CFM, cubic feet per minute per square foot. Or CFM per person, or some combination of the two. The requirements are based on a default occupant density for each space type, and traditionally fresh air intake was set at a constant rate to meet the required ventilation amount.
However there are some areas in a building that are not occupied on a regular basis and don't need the maximum ventilation rate at all times. In these cases, allows ventilation rates to be set based on actual occupant density as determined based on measurements in the space, either of carbon dioxide or using occupancy sensors.
In the case of a carbon dioxide , which is usually the most common type of demand controlled ventilation, or DCV. The outdoor air dampers will stay at a minimum value until the carbon dioxide meets a pre-determined threshold, at which point they'll open further to increase the fresh air provided to the space. Savings from DCV can vary significantly depending on the application. A technology alert published by the Federal Energy Management Program quoted savings of $.05 - $1.00 per square foot, so a pretty wide range. For government buildings one of the best applications for DCV are auditoriums and cafeterias in school buildings, and large meeting rooms in city buildings which all have very variable occupancy.
Strategy number eight moves on to lighting controls. We'll start with opportunities to use lighting only when it's needed. For interior spaces there's a field control options to turn off lights when they're not needed. First it's possible to turn lights on and off according to a set schedule. I mentioned earlier that I used to be the Energy Manager at BJ's Wholesale Club. On/off strategies were perfect for retail. There were a large number of overhead lights and display case lights that were scheduled to go off five minutes after the store closed.
For government buildings, the opportunities for scheduling are a little bit less straightforward, but it may be possible to turn off some rooms or corridors according to a set occupancy schedule. Possibly late at night I'm sure that lights are off overnight. Lighting sweeps are used more frequently in office buildings. When the building is unoccupied at night lights are sweeped off according to a set schedule, possibly once an hour. Occupants might still have some local controls to turn the lights back on if they need them.
And lastly, occupancy sensors can be used to turn off lights when a space is unoccupied. Occupancy sensors are likely to be the best option for controlling lighting in government buildings. And in most circumstances it may not be necessary to tie the occupancy base controls to an EMS system; however, whether or not tied through EMS, I still think occupancy based controls deserve a place in the Top Ten Control Strategies for Government Buildings â€˜cuz there are some good savings opportunities there.
An example of potential cost savings is included at the bottom of the slide. For a 50,000 square foot building, if lighting run times can be reduced by 1 hour per day through any of the strategies described above, savings of $2,000.00 per year could be achieved. So if run times can be reduced by more than one hour savings would increase proportionally.
This next strategy is also focused on using lighting only when it's needed. For exterior lights in parking lots or other applications, lights can be most effectively controlled by a combination of scheduling and monitoring of exterior light levels. So first a photo cell is used to insure that lights only come on when it's dark outside and not when it's light. But then on top of that, a time schedule can be used to limit the potential time the lights can be on. The schedule could start around 4:00 p.m., which is usually early enough during the darkest time of the year. And then the schedule can end when occupants will no longer be leaving the building or the parking lots.
If the lights were controlled only by a photo cell they could stay on all night, which is usually not necessary. And the schedules also allow the opportunity to turn lights off at a different time for different days of the week if activity schedules vary for a building.
The last of the Top Ten Control Strategies is also a lighting control strategy, but this one is focused on using only as much lighting as you need. With day lighting strategies, lights can be turned off or turned down when there's enough daylight to light a space. And day lighting can be utilized and space as either windows or sky lights. For different options for control you can turn off a portion of the lights, possibly every other fixture, or just those fixtures that are near the window or the skylights. Or it's possible to dim all the lights in a space, using fixtures .
Similar to occupancy sensors, day lighting can be accomplished without a connection to an EMS system, but the EMS may allow for more flexibility in adjusting light levels and controlling fixtures; so it can be beneficial. And if you can't make the case for day lighting based on energy savings, you can also consider the non-energy benefits. Studies have shown that day lighting in school buildings can increase students test performances.
So that completes my Top Ten Control Strategies for Government Buildings. I'm sure I haven't covered all the savings opportunities that will work for your building; a lot depends on your given systems. But you can think about the principles we discussed and determine what works for your particular situation. I do want to touch briefly on some more advanced control strategies if you have the ability to pursue these strategies which are a little more complex than what we've discussed so far, they can generate additional savings.
Trending is a modern equipment operation to identify opportunities for savings. I did discuss that earlier as one of the features of energy management system. And in addition to monitoring equipment operation, energy management systems also have the ability to track energy consumption, which again you can use to identify opportunities for savings.
Alarms can be used to report censor failures which can insure a persistence of energy savings. Load shutting is a process where you monitor the hold overload, and then find ways to limit the load at peak times to reduce peak demand charges. That's a little bit more of a cost savings strategy than a consumption savings strategy.
Similarly, sequential start up is the process of staging when equipment turns on in the morning. Also to reduce peak demand charges. And demand response is reducing loads during times when the grid is strained. Some utilities will offer incentives for customers that participate in the demand response programs.
If you have an existing EMS, and are using any of the strategies that we discussed so far, it's a good idea to invest some time to optimize the operation of your system. This slide details some recommended steps to insure the proper operation of your equipment.
First you should check all set points and schedules to make sure they're programmed according to the intended sequence of operation. Next you should calibrate sensors to insure that they're providing accurate readings; many of them can drift over time. You can check damper conditions for roof top units and terminal units to make sure the conditions are consistent with the intention of the EMS control strategies.
And once all this is done you can conduct functional testing of your system, which is a process of verifying operation of your equipment. You can force the sensors to have particular readings and insure that the system responds the way it's supposed to. And if you don't have the time or the ability to go through all the above steps on your own you can consider hiring a vendor to do a Rector Commissioning Study for your buildings, which I'll talk about more in the next slide.
Rector commissioning is a systematic process for improving building energy performance with the focus being on operational improvements. The best opportunity for rector commissioning is in medium to large buildings that have had an energy management system in place for several years. Any real savings are likely to be found in buildings that have a high energy intensity in terms of per square foot.
It's difficult to predict the cost in savings from a Rector Commissioning Study since it depends on the opportunities that are uncovered. However, a payback of two years or less is common; savings may vary from 5-25 percent, and cost can vary from $.10 - $1.00 per square foot depending on the building size and the building type. So if you have extra funding left over from some of your capital upgrade budgets, rector commissioning can be a good option to maximize the energy savings achieved in your building.
On this last slide I'm sharing a few resources that will be helpful as you consider installing a new energy management system, or optimizing the use of an existing system. The Energy Management Systems Guide is an excellent resource. It's part of The Operations and Maintenance Best Practice series by Portland Energy Conservation, which was funded by EPA and DOE. The whole series is very good, and this particular guide includes a lot of great information on energy management systems.
The ONM Best Practices Guide developed for the Federal Energy Management Program is also very useful. It has a broader scope, covering a lot of different operations and maintenance issues but there is one section devoted in particular to energy management systems. And then the Energy Start Building Upgrade Manual is also a helpful reference. In particular there is one chapter dedicated to rector commissioning.
So that concludes my presentation. We can now take a look at the questions window to see what kind of questions we received. I think I only see one so far which says "How hard is it to install building sensors in an existing building and its' building systems?" That's kind of a broad question and it probably depends what time of sensor you're talking about. I think most of them are certainly doable. Rich, do you want to field this one; I know you have a little bit more experience in the field than I do.
Richard Kline: Sure. No really it is gonna be dependent on what time of system you're trying to control and how much control you want to add in to the system. The industry's really made some progress in the past couple years in allowing you to retrofit sensors that provide you a lot of information, or allow you to gather information through your building automation system.
They have things like split core CTs that can be retrofit in to some of the more open protocol building automation systems that will allow you to gather demand data and energy data on the equipment that you're monitoring. And then you can make controlled decisions off of that because really the sensor is, for the most part, providing the input that then allows you to develop the output in order to control the system. So the more data that you need in order for the system to make a decision on what it wants to do, the more difficult it's going to be to install the sensor.
Now they actually have come up more with these wireless sensors where you don't need to run fiber optic or other types of 24 volt cable around your building. And that certainly has made it much easier to install the sensors and a lot of applications, especially in a multi-story building if you want to put sensors up very high and your control systems are very low. So there are gonna be some variables.
Sara Lisauskas: With a sort of related question that just came in, is there a certain building size threshold under which EMS doesn't really make sense and would be better served by not integrated controls? And maybe a sort of separate question is also are EMS typically standard practice - all right I lost the question there. Typically standard practice for large new construction?
I'm have to share a couple points and I'll see if Rich wants to add anything. I think yes there's probably a building size under which a full EMS doesn't really make sense. What that size is I don't know, maybe 50,000 square feet; I'm kind of guessing off the top of my head. Maybe even lower than though â€˜cuz some smaller schools I think would make sense to still use EMS. I know there's a lot of small retail facilities for example that there's a kind of specially designed control systems that might not have the capabilities of a full EMS system, but can do some really basic lighting and set points scheduling. So I think there are solutions for all size ranges.
Richard Kline: Yeah that's a good way to explain it Sara. You know it's really not necessarily size dependent as much as it is equipment dependent. If in a building all you have is a roof top unit, it's not gonna make a lot of sense to have a full scale building automation system because you don't really have anything to control. On the other hand, if in a small building you've got a variable air volume system with re-heat boxes, then it may make sense to have a more robust building automation system.
So it's more point driven how many points you wanna control versus do you just have - need a thermostat? That's really a good criteria to go by, points versus size.
Sara Lisauskas: Yeah that's a good point. One of the questions is "Do you have any experience with EMS in lab buildings?" I don't personally; I think that it would still make sense definitely to have an EMS. I imagine, depending on the type of lab you're talking about, there would be some more challenging control strategies associated with making sure you have enough fresh air in the lab, that kind of thing. And I don't know if any of the process equipment might be involved too, again depending on what kind of lab.
Richard Kline: Yeah there is a lot you can do really with labs. And the main thing in a lab that uses a lot of energy is that you are exhausting a lot of air with a fume hood. And a lot of these fume hoods, because of code requirements; need to run 24/7. And with a building control system and some variable speed drives, you can control the amount of air flow that's going out of the building.
Because you really are wasting a lot of energy when you're exhausting air, especially in like a clean room type lab where you're bringing in 100 percent outdoor air and you're having to condition that air. If it's a one - depending on the number of air changes required while there is a process going on in the lab, it can be very energy intensive. So you would benefit a lot - there can be a lot of savings from being able to control those fume hoods when there's not a need to be exhausting as much air through them. No that's a very good application for building automation system.
Sara Lisauskas: All right we have another question here, it's sort of long; let me wade through this one. "We have $8,600.00 in remaining AECBG funds that we would like to use in high efficiency interior lighting upgrades for a city facility. Do you recommend LED lights over T8s? We are finding some difficulty finding LEDs which we need that are made in America. We're also having trouble finding motion sensors that are made in America. Is there any guide that may assist us or do you have a recommendation?"
Maybe the first question is the - it's a little bit outside of energy management systems, but still a good question, "Do you recommend LED lights over T8s?" I still seem to think that T8s are the most cost effective, and possibly the most energy efficient option. There are definitely LED lights that are getting better in terms of both their performance and cost effectiveness. But I think in city facilities, I'm not sure there's a benefit there. I think that if you're changing out incandescent lights and a certain application of LED is a better choice. But I'd still have most city facilities lean towards your basic T8s.
Rich do you have anything to add on that one? Rich are you still there? We seem to have lost him. And I don't know of any guide that would assist in American made sensors, but I can look in to that and see if we can get back to you on that one. Okay I think I have a new question, "Can you comment on the possible benefits of having access to 15 minute electric usage profiles?" Even smaller buildings with or without EMS can now get this data in almost real time from some electric utilities. I'm a big fan of having access to 15 minute electric usage profiles; I think you can learn a lot from them.
But it does depend on whether you have a person available to look at them. So data by itself isn't particularly useful, but if you use that data it can be very useful. So if you have someone who knows what they're doing with it and can take a look at it person or an engineer you hire I think it is extremely beneficial. You can definitely spot what's happening, particularly at night, in your facilities. If lights are being left on or other equipment's being left on, if you don't see that energy use dip down to almost nothing at night, then there's usually some opportunities for savings you can find.
Scanning through I think we've covered most of the questions. Does anyone have anything else? I'll give it another minute or so just to see if any more come in. In the meantime, Courtney did you want to touch on the upcoming webinars?
Courtney: Sure. So we have a few upcoming webinars. This is the first webinar - or this is one of the few webinars in a series of webinars. So this is our up to date schedule for October, and we will have more scheduled in November and December as well. So you can check back on the DOE Solutions Center to register for these. And we hope you will join us again for the next webinar.
Sara Lisauskas: Take one quick look just to see if anything else came in.
Richard Kline: Yeah I just called back in; I'm not sure what happened.
Sara Lisauskas: Oh okay. Well I think you called back in right at the time where we were winding up â€˜cuz I think we've seen our last questions so -
Richard Kline: Okay did I get cut off in the middle of an answer or something?
Sara Lisauskas: I think we're all set. Courtney do you have any closing remarks?
Courtney: Okay so if we have no more questions, then I want to thank everyone for attending. And Sara and Richard, I'd like to thank you for presenting today. And we look forward to having everyone in attendance in our future webinars.
Sara Lisauskas: Great thanks.
Richard Kline: Okay thanks.