Wednesday, June 1, 2016

Energy Audits of Small Government Buildings

A walk through audit is just that--walking through a building, looking for quick and easy ways to save energy.  You're not looking to see if the occupancy sensor in a room needs to be relocated, but rather finding obvious energy-saving measures.  And when performed after benchmarking your building(s), you can save time and money by only auditing buildings that have a really high energy foot print for the type of building it is.  Here at SJVCEO we benchmark A LOT of small government buildings, so we have a pretty good sense of how much energy a City Hall of a certain size consumes here in the San Joaquin Valley.  Or a fire station, or even a police station.  And the more similar facilities we benchmark, the stronger our case is when we say “This building needs an audit. Here’s where it falls on the spectrum of similar facilities in the San Joaquin Valley.”  Wouldn't you like to know if you should be keeping up with the Joneses?  Or, what if you are the Joneses?
The first part of performing a walk through audit is to gather up all the information and equipment you may need before you walk in.  That includes:
  • An energy consumption chart of the past 12 month of energy consumption.  It may help you identify and/or confirms problems in the building.
  • Satellite imagery.  How large is the building?  Does it have an attached parking lot?  How many rooftop units might you encounter?  Google Streetview can help you here too.
  • The building's floor plan.  If you're marking potential energy-saving measures, you'll want to note where they are.  Also, so you don't get lost!
  • A camera phone.  An iPhone takes really pictures, has a built-in flash, and is thin enough to fit around tight corners.  And sometimes, the zoom is pretty decent too.
  • A light meter.  How much light hits the surfaces that are to be illuminated?  Is it enough, too much or not enough?  Ensuring there's the right amount of light hitting surfaces can reduce your energy consumption and/or increase office productivity.
  • A fluorescent ballast checker.  A T-8 lamp may look energy efficient, but it could be running on a magnetic ballast, known to consume more energy than necessary.  Using one of these lets you find out if they are without opening up the fixture.
  • A clipboard and paper.  You may not have a surface available to write on, and you'll definitely be taking notes along the way.
  • Typical energy consumption breakdown for the building's use.  You can go to the California End Use Survey (CEUS) website, which will show you on average how much each end use (lighting, cooling, heating) consumes for a type of building. The charts it produces help you focus your efforts by identifying where the largest amount of energy goes.
    Lighting, office equipment, and air conditioning
    are the largest consumers of energy
    in San Joaquin Valley small offices. Source: CEUS
Once you're in the building, you'll want to talk to individuals how may know the most about how the building operates.  When does the lights come on?  Who turns off and on the thermostat?  Speaking of thermostats...

Be sure to record the schedule and temperature settings of the thermostats.  Workers don't like to be uncomfortable, so the settings they plug into it might indicate a lot.  If they have the cooling temperature set really low, that might indicate a failing compressor or vents located in the wrong places.  You may not be able to point out a fix, but the building operators should definitely know to consider looking more into it.

Also, the schedule might be off!  Maybe it comes on 2 hours before work starts, or stays on longer than it needs to.  A lot of City Halls also hold City Council meetings at night, but typically not weekends, and especially not every night.  Those changes are quick and painless, and result in instant and often impressive savings.

Look in the cubicles.  Are there smart power strips?  Often overlooked, but employees aren’t at their desk all the time. If there’s nothing to turn off auxiliary devices when their space is vacant, there’s some additional savings.  While you're there, ask if the computers go to sleep or into hibernation automatically.  If they don't, there's even more savings there too!

Look for occupancy sensors in areas that aren't occupied often, like bathrooms and conference rooms, and especially Council chambers.  Lights in those areas are often left on longer than they need to be, and can be easily retrofitted for quick savings.

Take a look outside, too.  Some building-attached lighting can be really inefficient, and even more so if they are on an indoor switch.  Changing them to a photo sensor or time clock can save a lot of money without a lot of headache.  Even more can be saved by switching to LED.  The same goes for parking lot lights.  Their long run hours make for a quick payback, even if the building is on a time-of-use rate.

Once you're finished tallying up all the measures, you'll want to calculate how much each will save. Some will be easier (like lighting) than others.  Energy rates can be found on their respective utility company's website, or you can use a general Annual Consumption divided by Annual Cost for an average Cost per kWh.  Don't bother getting too bogged down in calculating exactly how much each measure will save, as this is just a walk through audit.  Prices for materials are easy to find, but labor can be a different story.  Find the prevailing wage rate for the type of work (for electrical, its typically Inside Wireman) and make an assumption for how much time the work might take, or ask your City Engineer for an estimate.  Take that cost, and divide it by annual cost savings, and you have yourself the Simple Payback.  You can even take the inverse of that number (1/X) and get the Return on Investment percentage too.  Do this for every measure, total it up, and do it again.  Some measures might have a long payback, but combined with faster payback measures, you can get a lot of savings very quickly!

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