Some Energy Savings Information for the Architect
Architects can increase energy-efficiency without huge, expensive
projects. Many energy-savings measures are free or low-cost, if
incorporated into the design and construction of new buildings or
renovation projects. They often have with little or no aesthetic
downside, and are usually easy to sell to the prospective owner.
Obvious examples include reducing the number of windows on the west
side of a building, landscaping the west side for shade, using
light-colored roofing materials, reducing the cement around a
building, and locating cooling towers away from heat sources. A
sharp architect can use the projected utility cost-savings as a
marketing tool.
A building comes together as the result of several engineering
disciplines and building trades. In all of these, you can design out
energy waste and provide permanent savings with low-cost options.
Just to whet your appetite, in a moment we'll take a quick look at
the electrical aspects. Going beyond electrical, you can also
address such things as (and this is only a partial list):
- Building envelope.
- HVAC.
- Mechanicals other than HVAC.
- Plant systems (plant air, plant steam, chillers and cooling
water, etc).
- Process systems.
With just the HVAC, for example, you can dig energy savings from
a thorough examination of:
- Central chilled water plant.
- Evaporative cooling units.
- Heat pumps.
- Package and unitary systems.
- Rooftop vs. grade condensers.
- Variable speed/volume units.
Don't forget maintainability issues, comfort, security, and
landscaping concerns when making changes. Failure considering these
issues can result in behavior that costs more energy than you save.
For example, you may remove a vent to reduce energy loss. But then
operators will prop a door open.
Electrical aspects it's good for an architect to learn about
The two most common electric bill reduction techniques barely
scratch the surface of what's inexpensively doable. These are the
installation of energy-efficient lights, and installing power factor
correction capacitors at the service entrance for a utility rate
reduction. Actually, not putting these capacitors at the service
entrance is smart. Instead, perform PF correction on each large load
individually. So instead of getting just a utility rate reduction,
you also get an actual reduction in power consumption. Just don't do
PF correction on motors with electronic drives. Instead, replace the
old drive with a newer, PF-corrected and harmonics-corrected drive.
Service entrance
Let's look at that service entrance, since we've now removed those
capacitors and done PF correction where it should be done. For new
construction, the location of your service entrance can make a huge
difference. So really do a thorough analysis. For existing
installations, it's usually too expensive to relocate.
Once you have a short list of potential locations that apply with
the applicable clearance requirements, maintenance access, security
requirements, and other issues that might rule out a particular
location, examine each candidate lcoation such that you can locate
the service entrance:
- Away from large heat-radiating surfaces (e.g., parking
lots), hot processes, and overly moist processes (e.g., cooling
towers).
- Near natural ventilation, but away from problems like
cottonwood trees.
- Where later expansion with reasonable access is possible.
If you have an existing installation, you may be able to
ameliorate less than optimum conditions through landscaping or
equipment relocation.
Grounding vs. bonding
Architects typically don't get involved in electrical
specifications, but may provide text for the general contractor as
part of project duties. In such a case, the architect must avoid
using the term "grounding" unless referring specifically to the
lightning protection system. In fact, the best approach is to say
"Ground or bond per the NEC, Article 250" in any place where you
need to mention any sort of grounding. And here's why....
Facilities that have "noise problems," high harmonics, and other
power anomalies nearly always have a situation where equipment is
grounded rather than bonded. Consult IEEE-142, the NEC Article 100
to understand what grounding is. It means connecting to the earth.
Grounding does not establish an equipotential plane. It's vital to
lightning protection. But on the load side of your service, you
should not have any grounding connections. Such connections create
ground loops. With ground loops, you get energy waste and
potentially lethal touch voltages. For your lightning protection
system, consult NFPA 780 and LPI0175.
For your load side, you want bonding. For bonding requirements, see
NEC Article 250, Part V and IEEE-142. Bonding deficiencies create
hazards to people and equipment. They also create various conditions
that decrease energy efficiency.
Internal power distribution
Architects generally don't get involved in the internal power
distribution, but may run into a situation in which they specify
service entrances, transformer pads, and other major infrastructure.
Since you're not an electrical expert, you may want to know a few
things about this. If you were the electrical engineer, we'd tell
you the following. Use it as the basis for understanding those
infrastructure issues.
It's far more efficient to distribute at 480V than to distribute at
120V. To optimize efficiency and minimize energy loss, run the 480V
distribution as close to the 120V loads as is practical. Today's CAD
programs allow you to experiment and see what works best. So, do
that. Try various locations for the various 208/120V panels to see
how you can get the shortest runs. It may be worth breaking up
things into smaller transformer and panel arrangements fed by longer
480V runs than to use one large central 208/120V panel in a building
or large room. Yes, you'll incur higher engineering costs, but you
may easily earn those back through construction cost savings.
Smaller switchboards, breakers, conductors, and raceway cost less
and are typically easier to install.
You might be using 277V for HVAC reheat boxes or lighting. If
possible, change these out to 480V. Else, use small 480-480/277V
transformers to derive 277V as close to these loads as is practical.
Follow a similar strategy with 120V loads.
Generally in a commercial building, 480/277V feeds the
infrastructure, and 208/120V feeds everything else. Generally in a
factory, 480/277V feeds the the infrastructure (including plant air)
and production equipment, while 208/120V feeds controls and offices.
If you have 120V lighting, start thinking about upgrade projects.
Now at this point, there is more we could discuss about feeder
circuits. And we haven't even started on branch circuits.
So, there you have an introduction to electrically-related energy
savings that result from good design choices prior to construction.
The typical electrical contractor doesn't know about these things,
though some do. If the client is highly interested in gaining
permanent energy savings, we do offer consulting services along
these lines. Write to Mark at sales@mindconnection.com if you would
like to provide such benefits to the building owner.
Check these Engineering Books, a fantastic resource!
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