Hello Campus Climateers!

Every campus has them – they are the worst energy offenders, the buildings and systems that gobble up energy.  I called them “energy pigs” in my headline to get your attention but – truth be told – I have nothing against pigs and I apologize to them for any unintended offense.

 

Every campus has its own list of worst offenders.  Here are some which many campuses have in common:        

 

Lab Buildings

For safety purposes, these buildings tend to have lots of outside air ventilation.  All that air needs to be heated up (in winter) or cooled off (in summer).  As fans pull outside air into the building, conditioned inside air is dumped from building outside air dampers.  During the heating season, this arrangement is worse than trying to heat your house with the windows open.  Moreover, the fan systems in older lab buildings were built to operate constantly (24/7, year round) at full volume.  We all want safety but this design was nuts.

 

What can be done about this problem?  Here are a few recommendations. 

 

In teaching labs it may be possible to actually turn off this ventilation when classes are not in session.  Since classes are mostly not in session (given evening and weekend hours), lots of savings are possible with this simple strategy.  In buildings that have more fume hoods than they need, unused hoods can be decommissioned or removed.  Don’t forget to cap the ductwork and then slow down the supply and exhaust fans – otherwise there will be no savings.  By the way, you might think that just lowering the hood sash will save energy.  But in older constant volume lab buildings with “by-pass” hoods, lowering the sash has no effect on how much air is pulled out of the room through the fume hood.

 

A whole-building approach to reducing ventilation air in lab buildings (without compromising safety) involves installing heat recovery coils in exhaust and supply fans or retrofitting the entire HVAC system for variable air volume (VAV) or two speed operation. VAV systems get complicated.  They need lots of pressure sensors, air valves and variable speed drives to reduce air flow but significant savings are possible.  Two speed systems setback fan air volume at night to a slower speed, thus reducing air flow, energy use, and, ultimately greenhouse gas emissions.  Reducing air flow through whatever means saves energy in two ways: fan horsepower and heating/cooling all that air.

 

Labs also have lots of energy consuming equipment.  For water purification, avoid distilling units (which boil water to clean it) and instead use reverse osmosis purification systems with decentralized “polishing” units where needed to further super-purify water when research requires it.

 

Electrically Heated Buildings

Many campuses have electrically heated buildings mostly as a result of bad decisions made years ago when it was mistakenly believed that we would have nuclear power plants everywhere and electricity “would be too cheap to meter.”  Also, way back then some campus decision-makers probably thought electrically heated buildings were a good investment because they were cheaper to build.  Oh my!  As we know now, these buildings are also very much more expensive to operate . . . for years and years and years.

 

Electrically heated buildings can be retrofitted to a hot water heating system fueled by natural gas or perhaps by a biomass-fuel boiler.  These conversions can be difficult, however.  You will need to find a place for the boiler.  And while it is not too expensive to replace electric heating coils with hot water coils in central fan system, it’s an entirely different story (and set of economics) to pick up the perimeter heating load by installing radiators everywhere. 

 

Another possibility is ground source heat pumps.  These can be powered by PV panels or wind turbines for a complete zero-carbon solution but they are expensive.

 

These alternatives can be expensive and challenging.  Many campuses will defer action on retrofits for years because they are concerned about payback – and then realize that if they had done the retrofit when they first thought of it, it would have paid back a long time ago.

 

Fan Systems that Push Too Much Air

Building fan systems are designed to meet peak occupancy and load, conditions which rarely exist.  If fans are running at a constant volume, it is possible to achieve very large savings by installing variable speed drives and appropriate sensors (e.g. CO2 sensors to measure occupancy) to reduce air flow during the 99% of the time when occupancy is reduced.  Since the energy consumed by a fan is a function of the cube of its speed, slowing down fans even a small amount produces very large savings.

 

At many colleges and universities faculty are away during much or most of the summer yet their offices are fully ventilated and air conditioned.  How to fix that?  Occupancy sensors could be installed in faculty offices and be wired to close off variable air boxes when the rooms are unoccupied.  This would be a big project -- with potentially big savings – if implemented across the entire campus.  The alternative is less attractive, i.e. wasting energy conditioning unoccupied rooms.

 

Old Heating Plants

Old heating plants are tough.  They are hard to keep running and hard to run efficiently.  One option to improve efficiency is retrofitting stack heat recovery.  Of course, a lot more energy can be saved at the plant if campus buildings were more efficient and demanded a lot less heat.

 

When retrofitting or replacing heating plants, it is importantly to not only consider cleaner burning natural gas (if you are now burning coal or oil) but also renewable alternatives like biomass.  Middlebury College in Middlebury VT has just installed a biomass plant.  In fact, their new power plant (a thing of beauty with glass walls so students can see it in action) is fueled as much by biomass as a strongly held conviction that Middlebury’s greenhouse gas emissions should eventually be net zero.  While we can’t all heat our campuses (and generate electricity) using biomass, according to a recent article in the New York Times other colleges are making this switch including Green Mountain College, Bennington College, University of Minnesota - Morris, University of South Carolina, and the University of Montana Western Campus.  And as I mentioned in an earlier article, Ball State University is shedding it old coal plant and planning to heat and cool its campus with an extensive geothermal heat pump system. 

 

Supercomputers

I have a small confession make.  Sometimes when I see all the energy being consumed by research equipment, I have momentary skepticism about science.  It’s just the energy guy in me.  I can’t help it.  Case in point is UB’s supercomputer.  When I first saw it, I hope the operators were telling the truth when they said all that computing power was being used at all times.  I felt faint watching thousands of lights blink on those racks and racks of spinning hard drives.

 

Google and others are coming up with more efficient designs for server farms and supercomputers so be sure to select the most efficient design if you ever install one on your campus.  All supercomputer applications can and should be equipped with heat recovery so the waste heat rejected by those spinning drives can be used to heat water or buildings elsewhere on campus. 

 

Windows and Light Bulbs

A quick fix for single glazed windows in cold climates is low-e reflective window film.  It will add effective R-value to the window to reduce winter heat loss while also reducing the cooling load by blocking unwanted direct gain in the summer. When you consider replacing windows, go as high tech and super-performing as you can afford. 

 

What is there to say about incandescent bulbs?   Try banning them.  They are really little electric heaters and shouldn’t have a place on campuses striving for serious reductions in energy use and a shrinking carbon footprint.

 

Next week’s subject is: getting the most out of an energy performance contract -- a great topic.  These projects have great potential as well as pitfalls. 

 

‘till then climateers!

 

Walter Simpson

enconser@buffalo.edu

 

Walter Simpson, CEM, LEED AP, retired 26 year University at Buffalo Energy Officer and director of UB Green, is working with AASHE and the American College & University President’s Commitment to develop a climate action plan wiki which is expected to be initially posted in March 2009.