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To help keep kids safe in our classrooms, the Center for Disease Control (CDC) recommends increasing the amount of outside air (OA) brought into a heating & cooling system. But is there a hidden cost to this?

The percentage of OA air brought into a building is a standard code requirement and varies depending on the type of building. The code standard for a school building is very different than for a manufacturing plant that uses toxic chemicals in their manufacturing process.

As you would expect, the temperature of the air outside is different than the temperature of the air inside the building. This means that when OA is brought into a building, it must be heated, or cooled, to match the temperature of the indoor space and keep people in that space comfortable.

Increasing the OA to an amount greater than what was intended in the system design will result in a heating and cooling system that is undersized, which may result in uncomfortable space conditions. This can also be harmful to the building because it may cause mold to grow since not all humidity is removed from the air prior to it entering spaces.

But there is a way to increase ventilation and still mitigate the impact on your utility bills. A demand control ventilation (DCV) sequence would vary OA amount depending on the total people in the space instead of bringing in a constant flow of OA at all occupied times.

The table below helps illustrate how a DCV sequence can help save money. Using a typical classroom as an example, this table shows the difference in cost between a code-minimum amount of OA (“Design OA No DCV”), OA brought in using a DCV sequence (“Design OA with DCV”) and bringing in 100% OA all the time (“100%”).

Note: This table is only considering bringing OA to a neutral temperature and excludes all other space loads required to keep the room at a comfortable temperature and humidity level. The red color denotes heating and the blue color denotes cooling.

As you can see, it would cost $292/year more to increase the OA to 100% from a code-minimum level. That might not seem like much until you consider how many classrooms a typical school building has and how many school buildings are in a school district.

This can end up costing a school district thousands of dollars more to heat and cool their school buildings each year.
This table also shows that the same school district could save a significant amount of money by implementing an DCV sequence. There is an extra cost to adding a DCV sequence to a system, but that cost will be recouped with the utility cost savings achieved.

If you aren’t sure if your building systems are bringing in the proper amount of OA, or if you don’t know if your system can bring in more OA, then you should consult a building systems engineer.

Making changes to the system without understanding the long-term effects can end up costing money instead of saving money and may be harmful to the system and spaces.

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About the author – Luke Lindesmith is a business development manager with Navitas. His background as a mechanical engineer and experience in the energy industry help him bring a practical approach to developing strategies for public sector clients who want guidance in how to initiate an energy conservation program in their facilities. He can be reached at llindesmith@navitas.us.com.

Originally posted December 11, 2019

The average age of school building in the United States is more than 50 years old. This means they were built before 1972. Older facilities require more effort to properly maintain them so that they can continue to serve the next generation of students.

Older buildings are also notoriously harder to heat and cool because of leaky windows, poor insulation, and aging and inefficient building systems. As such it is very common for K-12 facilities to waste millions of dollars in excess energy consumption without knowing it.

But the good news is that by actively working to cut utility costs, school districts can easily reap savings. These savings can then be used to help fund needed facility improvements.

One of the ways a school district can take advantage of this is through an Energy Savings Performance Contracting (ESPC). An ESPC is a budget-neutral approach to make building improvements that reduce energy and water use and increase operational efficiency.

By partnering with an energy service company (ESCO), school districts can use a guaranteed energy savings performance contract to pay for today’s facility upgrades with tomorrow’s energy savings; without tapping into capital budgets. Through the guaranteed savings program, the dollars that are paid out to utility companies can be reduced and the corresponding savings can help fund needed facility improvements.

The basic process for schools to move forward with an ESPC are:

1. The school district decides to utilize the ESPC process and competitively selects an ESCO.
2. The school district enters into a contract to the ESCO, who will conduct an energy audit of their facilities and develop an implementation proposal, which identifies potential energy conservation measures (ECMs). A wide variety of measures can be included in an ESPC project. Typical ECMs include upgrades to lighting, water control systems, HVAC units, windows, roofs and building automation systems. The ESCO will identify each potential measure and estimate the itemized cost and saving, but the bottom line is what determines which bundle of measures can be included in the ESPC project. Some measures with short payback periods (e.g., lighting) can offset those with longer payback period (e.g. boiler and chiller replacements or renewable energy systems) if they are bundled under one contract.
3. The school District works with their municipal financial advisors or lending institutions to arrange for upfront financing. One of the most common financing for a government ESPC project is a municipal tax-exempt lease-purchase agreement where the school district will issue a certificate of participation (COP) with a lending authority. Districts should also consider internal financing or general obligation bonds and compare rates and benefits. Typically, approval is only required by the Board of Education and financing institution.
4. The ESCO implements agreed-upon ECMs, then monitors energy savings success through measurement and verification.

ESPC projects can include one school facility, or all the facilities within the school district. The size and scope of project is governed by the savings opportunities in the facilities, the types of funding sources that can be applied, the minimum size project an ESCO is willing to manage, and the financing capability. Schools facilities are generally good candidates for ESPC projects, because with long-term ownership of the facilities, most state legislation allow for 15 to 20-year financing terms.

For additional information, check out the US Department of Energy, Office of Energy Efficiency and Renewable Energy

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About the author – Paul Harrell is a business development manager with Navitas. His background as a Certified Public Accountant and 33 years of experience in the education sector help him bring a practical approach to developing strategies for school districts wanting guidance in how to manage their overall budget and utility costs. He can be reached at pharrell@navitas.us.com or 913-344-0049

Your mobile phone buzzes at your desk and you glance away from your emails to see the notification holds great news, “Your order has shipped!” A big relief -with that special-ordered part on its way, there is still a chance the unit will be repaired in time for Open House.

Back to the emails.

Now it’s time to head over to the new convention center for the ribbon cutting. Final walk-throughs and inspections consumed most of yesterday, but you’re still banking on this afternoon for a chance to catch up on some of your planned-facility reviews. Budgets will be due soon, and you want to make sure everything is operating efficiently to keep costs manageable.

In the lives of facility owners and operators: schedules are tight, demands are great, and resources are limited. Finding a way to “accomplish it all” is the objective. Each facility contains thousands of working parts that are necessary to maintain the desired environment. Add different space needs to heating/cooling season changes; then, multiply by the number of facilities in your portfolio. The pressure for optimal building performance and the resources to accomplish this feat, is immense.

Budget time rolls around. While you’re happy with some of the gains made in different areas, you’re perplexed as to why one of your newest facilities is the most expensive to operate. You recall a former colleague worked in the energy-efficiency industry before retiring. Your friend stumps you with a question: “What does your weekend energy consumption look like?” Seems like a strange question given that staff and production occur during weekday hours only. Nonetheless, a weekend audit is the next logical step. Your walk-through reveals some opportunities for savings such as a few fans and lights that were left on, but nothing as substantial as you were hoping.

On the drive home, it hits you: “We need to be measuring and tracking at a granular level. We need building metering!”

Sure enough, just days after installing the metering, it’s evident that a large energy draw is occurring each evening. Knowing the magnitude and types of equipment in the building, you are quickly able to determine that spike in consumption is tied to the central chiller that provides cooling throughout the building. The best part is that it’s only an issue with the schedule and can therefore be resolved quickly.

At the end of the next month, the energy bill has reduced significantly.

Installing interval metering on electricity provides you the ability to quickly determine which facilities are deviating from expected consumption before the bill arrives at the end of the month. When paired with an analytics platform, a large portfolio of facilities and equipment can efficiently be reviewed. Facility walk-throughs are helpful, but first identifying a targeted set of buildings/equipment to investigate, cuts down on time and effort. Additionally, the issues leading to energy waste are generally occurring at inconvenient times of the day when your facility is vacant.

When it comes to the dilemma of, “Schedules are tight, demands are great, and resources are limited,” accomplish it all by leveraging the power of data to make the most of your time and resources. It’s impossible to know what all equipment is doing at all hours of the day without technologies such as metering and facility analytics.

While in a meeting the next month, that question that used to cause you great anxiety comes into your mind: “Is that chiller running again, and driving my budgets out of balance?” Now, in just a few clicks of the mouse, you access your metering and facility analytics to answer that question before moving on to the next task at hand.

Objective met.

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About the author – Zack Flageolle is Navitas’ Director of Optimization Services. His experience in planning, design, and construction has allowed him to gain a greater understanding of what makes a successful project. He provides leadership of our Optimization Services activities for our clients and is instrumental in ensuring the program is successful. He can be reached at zflageolle@navitas.us.com.