“The 6-to-6 Curse”

By Emily Breeden of Rocky Mountain Trane

Is your Building Automation System helping or hurting your energy bills?

A majority of the buildings the Trane Intelligent Services team looks at has schedules that don't match their occupancy. This means that the building systems are running (lights, HVAC, etc.) when people aren't actually there. Often, building owners don't even realize this is happening.

Why does this matter?

  1. When your building automation system is in “Occupied” mode when the building isn’t truly occupied, the systems work much harder than they need to. For example, if your building’s morning warm-up routine is scheduled say, four hours earlier than when people start coming in for work, your heating system will think your building is occupied and will over-work just to get the temperatures to an acceptable set-point. If the building heats up, and people (a.k.a. mini-heaters) aren't there to bring in some BTU’s, the heating system will have to work that much harder to keep it warm until it is actually occupied. This is a huge waste of energy, which translates to unnecessarily high utility bills.
  2. Longer run hours for equipment and systems means shorter equipment lives. When you invest in heating and cooling equipment, you expect it to last 10, 20, even 30 years, right? Well, think of it as a car. If you were to drive your car around all the time, for no reason (simply just to drive it), then the car’s “life expectancy” would obviously decrease. You’d have to constantly stop to pay for gas, spend money on maintenance, and it would degrade in a much shorter amount of time than if you only used it when you truly needed it. By optimizing your schedule for when you drive it, and by driving it smoothly (i.e. not slamming on the gas and breaks all the time), it will last a much longer time. And as we all know, time is money.
  3. Optimizing your schedule means taking control of your building. Having more control means your occupants stay comfortable. Keeping your occupants comfortable translates to money. The cost of having an uncomfortable environment — which results in sick days, employee dissatisfaction, turnover — can translate to thousands, and thousands of dollars.

How does this typically happen? 

Schedules can get out of whack a few different ways. One common issue is that with new construction projects, most building automation schedules are defaulted from 6am to 6pm, seven days a week. That’s where “The 6-to-6 Curse” title comes from. While a 6-6 schedule is fine during the construction period, what happens when the building becomes occupied? A lot of times, the schedule is never updated. That means building systems are running 12 x 7 = 84 hours a week, regardless of when people are actually in there.  Even worse, sometimes certain equipment/area schedules are defaulted (or overridden, which could be a whole other article!) to 24/7. Depending on how long it goes before someone catches it, you could be wasting a lot of energy and money.

Moral of the story… review your BAS schedules!

You can save 10-15% in energy just by optimizing the start and stop times in your building.  Maximize your off-time while also maximizing comfort, and watch your energy bills decrease!