An easy controls change to reduce daily peak electrical demand (and other CCx Feb. 2019 highlights!)
Hello, my name is Adriane Cooper and I am with Cooper Commissioning (CCx). So far, I have been working on the administrative side of CCx; I am excited to now be learning more about the technical side of the business and I am excited to be able to brag about the great work our agents do.
Towards those ends, it is my goal to post here roughly monthly with some tips for building Owners/Operators as well as brag about some of the headaches our agents have been solving for our clients.
Skip ahead to here to get right to the info about an easy change to your controls to cut your daily peak electricity demand. Otherwise here’s some more info about what we do in general and other fixes our agents brought to our clients this past month.
Nearly every building is a one-off build with uniquely designed systems, so it isn’t surprising that issues with the mechanical systems arise. We know it can be a nightmare when your building isn’t working, especially if you feel like you are fighting the same problem over and over without ever getting any real resolution. Please keep us in mind if you run into issues, we would love to help!
While it is true that in order to get the best running building possible, commissioning should be brought on during the design phase, every building can benefit from the systematic examination and coordination that commissioning offers no matter when commissioning is implemented.
To sum up what we do: our agents make sure buildings work. I would love to go on and on about how we do that: why commissioning is critical to today’s buildings, the details of how our technical approach works. etc…… but a better way for you to get an idea of what we do might be for me to highlight some of the problems our Commissioning (Cx) Agents have helped our clients resolve in the past month.
Here are examples from just two projects we worked on in the past month. (And each of these examples are ONE of dozens and dozens of issues addressed by our team on each project – just this month!)
Today I happen to be sharing examples from existing buildings that are being retro-commissioned by our team.
Our agents completed a design review for a building Owner that will be spending $60,000 to purchase new humidifiers. Our agents raised the following issues that otherwise would not have been caught until installation was underway or complete. To fix each of these once installation has started would have been either expensive or impossible. Changes on paper are easy, but much less so once the project is underway.
Owner could save $10k/year - every year - in operational costs if they used natural gas instead of the electrical humidifiers the Design Team called for.
The humidifier manufacturer’s installation material indicated that the minimum clearance below the unit should be 7 ft and to have 2 ft above the unit for filter access and airflow clearances. The design did not meet these minimum requirements, nor was there space below the ceilings to even achieve this. The steam discharge would have been directed right into the face of a passersby!
Spec from engineers called for humidifiers to talk to BAS. However, the cost for installing components that would have physically connected the humidifiers to the BAS, nor the integration of the humidifiers with the BAS was NOT included as part of the original design.
Owner would have been sold equipment that could ‘integrate seamlessly into current BAS.’ But for the equipment to actually be controlled by the BAS would’ve required services not originally called for in the spec: installation and integration. The Owner would not have been aware of this until the humidifiers were already installed, leaving no choice to the Owner but to pay whatever the supplier/contractor required for this service.
To find this level of detail in a spec takes experience: the language used is subtle and would not be caught without a detailed reading of specs. This sort of simple oversight is often the result of no one on the team: designers, vendors, or Owners having the experience to take all components of the mechanical system into account. If caught early and on paper these are super easy fixes; if caught later (or not at all!) these simple oversights can add up to large cost overruns for the Owner.
Undersized (by 100%) humidifier
One of the proposed humidifiers which was to serve two floors only took one of two floors into account when calculating capacity. So the humidifier called for in the specs had literally half the capacity required.
This would have been a $10-15K expense to fix if it had not been caught in our design review.
Our agents have just started on a project evaluating an existing building for functionality, energy usage, etc. One issue they found – and it was easy to find because they find it in basically every building they see – was the fact that the BAS called for three air handlers coming online all at exactly the same time every morning.
This creates a huge ‘Peak Demand’ for the day. (The startup of large equipment consumes large amounts of power – as much as 20 times as much as just running the equipment does.)
Pumps, air handlers, electric heaters: the start up energy use for each of these is high. Controls should be set so that their programmed start time are NOT all at exactly the same time. However, often the ‘default’ seems to be that many of these are set to start at the same time.
As this is an issue in almost every building we see – chances are it is an easy place for you to find some savings on your utility bill. Here are a few things to look at:
Have your Controls Contractor or Maintenance Staff look into the daily start up sequence of your major equipment.
Change the startup times so equipment comes on in stages – even by just 1-2 min.
Just by staggering start up times – even by 1 or 2 minutes! - for major pieces of equipment you can significantly cut your electricity bill because part of your charges is based on PEAK DEMAND: which is a really easy thing to lower by tweaking the times equipment is scheduled to start up.
Look into your utility plan: what you are paying for Demand vs. Usage?
Demand is the highest amount of power you require at ONE TIME in any given day.
Even with low usage, if this number is high, your bill will also be high.
Usage is how much power you actually use.
We highly encourage you to investigate your utility bill to see how much ‘peak demand’ – NOT usage! – is costing you, it can be as much as half of your electrical bill. But utility companies don’t necessarily make it obvious on your invoice. See an example here and more about that here.
It is my understanding that your utility company would prefer for your peak demand to be lower because then they have a less variable demand they need to account for.
A couple of BONUS tips to reduce your electrical bill now (Tip 1) or with purchase of new equipment (Tip 2):
Bonus Tip 1: if you don’t yet have variable frequency drives (VFD) on your larger (5HP+) motors, they are an investment that will pay you back in less than a year.
Bonus Tip 2: If you EVER see ‘’soft start” on a spec instead of a variable frequency drive. FULL STOP. Variable frequency drives have come down in size and price and NEVER AGAIN should you install a soft start to gradually bring equipment online. VFDs will provide the same function but with a higher degree of control.
I hope some of these examples and tips can give you some insight into all the minutiae that affect how your building runs. Unless you have commissioning on board (or have commissioning duties specifically assigned to your senior maintenance staff) I guarantee your building is running sub-optimally and you are very likely spending significantly more for energy than you need to.
Please feel free to give us a call if you are experiencing frustration with your building, if you would like to spend less on utilities, or have any plans in the works for renovations, additions, or new construction. The number of headaches we can prevent and the amount of savings you can reap by having commissioning on board is astounding.
And don’t forget to call your controls contractor or check with your maintenance staff on how your daily start-up sequences look. If everything is coming online at once, stagger those times just a little – minutes are often enough - for significant savings on your electrical bill.
All these tips are brought to you by our outstanding commissioning agents who are meticulous, conscientious, and tenacious in getting building systems to work. The fact that among them they have decades and decades of experience running and commissioning large facilities allows your headaches to be their interesting (and they would even say fun) puzzles to solve.