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Dr Paul's Guide to Saving Energy Around the Office
Here are some simple strategies which will save you some energy and
money. They are general principles only. All buildings perform differently
depending on their location, design and age. To get specific advice
for your building, you need to get us to have a proper look for
you. Given that an average office building can save up to 30% of
its energy use without trying too hard, it's definitely worth the
effort!
One of the wonders of the modern day office is that it is almost
impossible to tell, as an occupant, whether it's super efficient
or an energy hungry monster. Given that reality, why should you
care? Does it affect you, as a mere building occupant? The answer
is, resoundingly, yes. Some reasons:
- Research suggests that there is a link between poor building
maintenance, poor energy efficiency and poor indoor environment.
Your dry eyes and gasps for fresh air may be a symptom of an inefficient
building.
- Energy is typically up to 5% of the total costs of running an
office-based organisation. Sounds like peanuts? Well, think again:
if your organisation has more than 20 staff, that 5% represents
somebody's entire salary. Your building could be threatening your
livelihood.
- Energy in offices represents approximately 9% of total energy
use in Australia and New Zealand, and more in larger industrialised
countries. Controlling the energy use of your office helps reduce
energy use, which helps reduce pollution, including smog and
greenhouse gas emissions.
The very first step in understanding how energy efficient your
office is to find out how much energy it uses. Thus may not be as
simple as it sounds. If you are lucky, there will only be one energy
bill, covering everything. More normally, however, there will be
one bill for the lights and equipment power on your floor(s), and
a share of one or more communal power bills, covering lifts and
the air-conditioning. Don't forget the gas, oil or coal bills, if
relevant. Unless your company has already done something about energy
efficiency, there may be quite a hunt to find all this information.
To make things worse, you will really need to gather the energy
bills for all the other tenants in the building to understand how
much the whole building uses.
Once you've got all the information together, work out the total
energy used in the last year in kWh. Be aware that you will need to
convert non-electrical fuels from a wide range of units to kWh.
Ring up the suppliers of your non-electrical energy - they should
be able to provide you with the necessary conversion factors. Now
divide the total kWh by the net lettable floor area in m2.
You can get gross floor area from plans by measuring the floor area
of the building (excluding carparks, plant rooms and external balconies).
You are now finally equipped to find out how good - or bad - your
building is in terms of energy use. If you are in Australia, log
onto the Australian Building Greenhouse Rating scheme website at
www.abgr.com.au and do a rating of your building. I can thoroughly
recommend this because I was and still am the lead technical developer
for it, but also because it has achieved a really high level of
support from the industry. Alternatively, check your building against
the ratings below, which are based on total energy use (air conditioning,
lighting and equipment):
It's a miracle!
Less than 100 kWh/m2. Hey, wow, either you are in an amazingly
energy efficient building, or you forgot to add in some of the bills.
Check again before breaking out the champagne! However, there may
still be good energy savings opportunities. Often small buildings with relatively
rudimentary services can perform at this level without a great deal
of difficulty. As a result they can still have good savings available. Reason to be cheerful
100-200 kWh/m2. Buildings in this range are performing well. There
will almost certainly be good energy savings opportunities, but
you have a basically functional building, particularly if energy
use is below 150 kWh/m2. The unhappy median
200-300 kWh/m2. The average energy use of office buildings in both
Australia and New Zealand is approximately 250 kWh/m2. But don't
think that this means that your building is OK. Buildings in this
region often have quite serious energy waste problems. It's just
that serious energy efficiency performance problems are normal practice
in the industry! Intensive care required
300-400 kWh/m2. Buildings in this region have real problems. Bear
in mind that by this stage, your building is using three to four
times the amount of energy that a perfectly operating building should.
Get help now! It's a dinosaur
400kWh/m2 and over. If your building is using this much energy,
then it probably has a serious problem - or a some large piece of
equipment like a major city telephone exchange or three floors of
shops. In the absence of such obvious explanations, I would expect
to find major problems with the control of heating and ventilation,
and quite possibly a terrible lighting system. The scope for energy
savings could be huge: you may be using twice the national average
and three times what a really good building would. act now!
The above classifications are based on a standard office building
working five days a week, and won't work if you have two floors
of mainframe computers and a telephone exchange downstairs or if
your office works seven days a week. The Australian Building Greenhouse
Rating provides a much better scale and process for dealing with
those problems, so use that if you can. And if you are working seven
days a week, delegate energy efficiency issues to someone else and
focus on getting a life!
There are a million office buildings out there that have had professional
energy efficiency experts survey them and identify great savings.
Unfortunately something like 90% of these reports end up as shelf
fillers and are never acted upon. This is generally because company
structures just aren't conducive to anything being done. Consider
this: Management commissions an energy audit. The building manager
is given the task of handling the report, which finds some savings.
Now, what can he/she do? Present a report that says that he/she
has cost the company money through not seeing the energy savings
opportunities? Without support to get over this hurdle, many excellent
energy savings opportunities go to waste. Find out whether your
office has had an audit done. Was anything done about it? How long
ago? If it was more than five years ago, it's time to repeat the
whole thing again. Many of the most cost effective energy efficiency
measures are maintenance related, so time tends to produce new opportunities.
If you want to save your company some money, get management support
to set up an energy action group, set yourselves some real goals
and go for it. It's an ideal opportunity to do something for the
environment, improve your company's profits, and impress your boss!
Computers and other office equipment
Many people still believe that it is important to leave a computer
running constantly to prolong its life. While this may have been
true back in the bad old days of amber screens and 1MB hard drives,
it's certainly not true now. Consider this: you are in your office
for a mere 25% of the hours in a week. A modern computer may only
use 100-120W but, added up over the dozens of computers in your
office, not to mention the millions of computers nationwide, that's
a lot of energy. What's more, overseas research has shown that turning
your computer off actually lengthens its life. After all you don't
leave your TV on all night for fear that turning it off will damage
it! So some simple rules:
- Turn your PC off at night unless it needs to be accessed remotely
in your absence.
- Turn your monitor off if you are going to be away from your
computer for more than 15 minutes. Screen savers may be pretty
but they don't save energy.
- Enable the energy saving features of your computer. You may
have noticed (on newer computers) that when you turn it on it
shows an "Energy Star" symbol in one corner. This means
your computer has settings that close it down partially after
long period of non-use. Unfortunately this doesn't mean that these
features are enabled, so check this out or get your local computer
whiz to do it for you.
- Don't turn your PC on until you need it! In some research I
did a few years ago, we found that in a typical office building,
70% of the computers are operating but only 30% of those are actually
in use. Would you turn on your car and leave it running just in
case you wanted to use it later on?
- Don't EVER turn off a PC that may be operating controls, operating
as a network server, running an old or unfamiliar operating system,
or is otherwise outside your domain of understanding. An error
in this respect could make your life very uncomfortable.
- Similar rules can be applied to office equipment such as printers
and photocopiers but be careful - you could make lifelong enemies
by turning off equipment that is needed by other people when you
don't expect it. Rather than becoming an office equipment vigilante,
form an energy conservation team and get your company to set a
policy on turning off equipment. This will save more money than
anything you can do individually.
The key sins of inefficient lighting are lights on in empty rooms,
too much light, and badly planned light switching layouts. You can
improve on some of these problems quite easily. However, before
you touch anything, check your local regulations and/or your local
occupational safety and health representative first as to whether
you have to be an electrician to work with light fittings, and always
use an electrician if you don't know what you are doing. Energy
savings aren't worth being fried for.
Turning lights off
Incandescent bulbs are inefficient and should be turned off immediately
they are no longer needed. Fluorescent lights are affected by being
turned on and off too often. If these are not going to be needed
for 15 minutes or longer, turn them off.
Delamping.
If there's too much light around it's OK to take tubes out of fluorescent
fittings. You can disable a tube easily by removing the starter,
(which is the little cylindrical thing visible in most fittings).
Selective relamping.
If you have older style tubes (called cool white or colour 33)
you can often replace these with newer triphosphor (colour 84) tubes
which give out 50% more light at the end of the tube life (which
is what your lighting will be designed for. This means that you
can often leave a lot of tubes out, saving lots of energy.
Daylight.
The sun's light - particularly the diffuse light out of the direct
beam of the sun's rays - is great to work in and is much cheaper
than electricity. But it only saves you money if you turn your lights
off when there's enough light around from the windows!
The above tips help deal with energy use on any lighting system,
good or bad. However, how can you tell whether your lighting system
is an energy monster or a sight for sore eyes?
There a million reasons for a lighting system to be poorly designed.
The first is that half of them were never really designed in the
first place, they just sort of grew. I encountered one such system
where the original building had been fitted out by a speculative
developer - and then tenant had added in a few extra fittings. In
this case, they had nearly doubled the lighting energy, for no good
reason.
When assessing your office's lighting system, there's two basic
questions you have to consider.
How much light do you need?
For an office this is typically 320 lux (this is the minimum requirement
under the current Australian Standard), which you can measure using
a light meter. Your local occupational safety and health people
may have taken some measurements of this to make sure you are not
struggling with too little light.
From an energy perspective, however, the problem is that more than
this is a waste of energy and may even detract from your visual
comfort. This is particularly the case is you are glued to the computer
all day. For heavy computer work, you are better off with 240 lux
general lighting and a desk lamp shining on any written material.
How efficient is the lighting system?
Assuming you are getting a reasonable level of light, it's possible
to do a quick check on your lights. The procedure I'm about to describe
isn't one for the purists, but it does provide a real quick sanity
check on your lights. Take a typical floor of your building. What
you need to do is count how many fluorescent tubes there are, in
total, on your floor. Note that any given light fitting (also known
as a luminare) may have anything from one to four tubes in it.
Tubes come in a variety of sizes but the main types are either
1200 mm long, or 1500 mm. For each 1200 mm tube, count 45 watts,
and for each 1500 mm tube, count 67 watts. These figures allow for
medium technology tubes and control gear, combined. There are lots
of other tube types around, and if yours don't fit those categories,
then you are out of luck because I'm not going to go through all
the possibilities. However, those two types will probably cover
90% of what's around. Add up all the watts of all the tubes and
divide by the lit floor area, to get a figure in watts per metre
squared (W/m2).
A good lighting system will be 10 W/m2 or less; best practice for
open plan offices is around 7W/m and average practice seems to be
around 15W/m2. In practice, one can generally bring an existing
lighting system down to 12W/m2 without spending an exorbitant amount
of money on it ö typically one can obtain a payback of less
than 2 years on this sort of exercise. If your current lighting
power density is greater than 20 W/m2 a total replacement may
be in order!
Poorly performing lighting systems require professional help from
an energy efficiency expert with a good background in lighting. We
can provide this sort of help.
You may have encountered a few other lighting nasties while you
were looking around. These include:
Dirty light fittings
A dirty light fitting doesn't use more energy, but it does deprive
you of light. Make sure your lights are cleaned once every six months.
Incandescent bulbs
An incandescent bulb is the same sort of bulb that you would probably use
at home, and in general, that's where they should stay! Any light
that operates for more than 3 hours a day can be profitably replaced
with a compact fluorescent, as long as it's not on a dimmer circuit
or in a closed fitting. Closed fittings seem to shorten the lifespan
of compact fluorescent fittings.
Flickering tubes
How anyone can work under a flickering fluorescent tube as it shuffles
off its mortal coil is beyond me. However, they are a sign of something
more sinister: if your tubes get to this state, it means that they
are being allowed to run too long. As they get older, they get dimmer,
and by the end of 15,000 hours operation you may only be getting
half - or less - of the intended light output. Timely replacement
will improve the level of service you get from your lights, which
is a form of efficiency even though no energy is saved. Furthermore,
if tubes are replaced in batches rather than individually, it saves
labour costs.
Spot lights
It has become very trendy to put little spotlights in buildings.
You know the sort of thing - little Christmas tree like lamps with
reflectors, known variously as low voltage lights, halogen spotlights
or dichroics. I don't like these much, because they are inefficient
and, one worse, cause big glare problems. Try to look at a ceiling
full of them for a minute and you will see what I mean.
38 mm tubes
Fluorescent tubes come in two basic diameters, 38 mm and 26 mm.
You can spot 38 mm tubes either by measurement or by looking at
the wattage ratings, which are written on the tubes: 1200 mm fittings
are 40W and 1500 mm are 65W. By contrast, 26 mm tubes are 36W and
58W respectively, a 10% saving. Before you ask, yes, they do put
out the same amount of light and yes, they do last as long. What's
more, they cost less. In any modern fitting these tubes are fully
interchangeable so it's possible to make a 10% efficiency improvement
over time just by changing the tubes you by as replacements! Some
very old fittings don't work with 26 mm tubes, but if you still
have such fittings you should be getting them replaced because they
will be inefficient and may well contain PCBs - chemical nasties
that you do not want in your building.
As you can see, there are plenty of things you can do with your
lights. A number of them cost nothing and save lots. Some of them
cost a fair bit but save bucket loads of money. In many cases, a
big lighting upgrade will give you a more pleasant working environment,
too. So you've go no excuse - do something about your lights today!
For the night-owls whose work days extend into the evenings and
weekends, it's not necessary to turn on the heating and ventilation
for the whole floor or building just for you. If winter time cold
is the problem, it's much more economic for your office to buy a
few little electric heaters and hold them as a pool for people to
borrow out of hours.
On one of our sites we use a heater design that has a one hour
push button and a decent thermostat on it, and even on quite busy
weekends, the energy consumption is much less than it would be if
whole floors were being heated. If you need a heater like that,
call us, because we designed the control! For offices where cooling
is the big issue, you may have to turn on the air conditioning to
bring the temperature down when you arrive.
However, once you've got the right conditions, turn the air-conditioning
off again. Air-conditioning systems can spend a lot of energy doing
very little at low loads, so the best way to reduce after hours
air-conditioning costs is to keep running times as short as possible.
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