Cooling down in the office – too hot at work 2 – create a draft

June 30, 2008

Create a Draft

When people are too hot in the office, a regular action is to open the window, but the effect can be increased greatly by encouraging a draft. I mean if you think about it, you open a window, trying to let air in, well where is the hot air already in the office going to go (simple fluid dynamics???)? You need a flow of air so the hot air has somewhere to go, and the cold air from outside is sucked into the office space.

So here is the theory bit. Hot air rises. That’s the key point. If you were to take a good thermometer, and take measures on the floor, and near the ceiling of your office, you’d probably see about a 2C difference.

So, if you have an open window, and assuming there isn’t a breeze outside, the first thing that will happen will be hot air will try to escape. What you need, is a second window open, at a lower level to allow cooler air to come in. The ideal office space looks like this.

If not, even having them at the same level is good.

Plastic Bags – I never realised how funny they can be

June 27, 2008

Tips to reduce your TVs Energy Consumptions

June 25, 2008

Turn the TV off when it’s not in use

All too often people leave their TVs going in the background.

Off! Not standby

If you consider just how many hours your TV is likely to spend on standby, the energy really does add up. Older TVs are particularly bad for consuming large amounts of energy while on standby.

Turn off the Quick Start option
Many newer TV have an option called Quick Start or something similar, which keeps the set “warmed up” and so makes the it turn on more quickly when you press the power button. It consumes far more power during standby mode however.

Turn down the brightness

Most TVs will allow you to control the brightness of the screen. If the room is less bright, then the TV does not need to be as bright to give the same appearance. So… there can be a double saving here. Most TVs also give better image rendering at lower brightness levels

Control room lighting
If your room is less bright, you can turn down the TV brightness.

Does your TV have a power-saver mode?
Have you tried it?

Watch TV together
Be a bit sociable for gods sake!

Watch less TV
Well obviously!

Cooling down in the office – too hot at work 2 – night cooling

June 23, 2008

Night Cooling

In almost every part of the world the night time temperature is cool enough to have the effect of cooling down the office. So simply put night cooling refers to the idea of recognising that you will be in need of cooling the next day, and so maximise the cooling that is achieved at night. That can be achieved by

  1. Making sure no heating is switching on during the night
  2. Switching as much electrical equipment off as you can at night, so it is not playing a part in heating up the office (this works for daytime too)
  3. If it is safe to leave windows open – NOTE – Make sure you’ve switch off the heating/cooling if your going to do this, as the heat/cool will just escape
  4. If its not safe to leave the window open, consider precooling the space by setting the timer to come on earlier and have the space “precooled”. In every country I can think of “offpeak” electricity is more environmentally friendly, and in some cases its cheaper.


Why cycling is good – get on your bicycle

June 21, 2008
  • No Petrol/gasoline means reduced emissions from your car
  • Petrol/gasoline costs money, there is a big saving
  • It’s good for your health
  • Reduces congestion
  • In cities, is regularly faster
  • The trip time is very reliable
  • You can park right where you want to go
  • Maintenance costs of a bike a far lower

Why not get a bike, and cycle for 1 trip in 10.

A Guide to Biofuels

June 20, 2008

I think there are lots of posts to come on Biofuels, but this is a simple one to kick off to outline the differences between the options.


Replacement for – Petrol (Gasoline)

Made from – fermenting and distilling high sugar/starch crops. Examples of high sugar/starch crops are sugar beet, sugar cane or corn.

Availability – Bioethanol is available in a large number of service (gas) stations. Also different countries are allowing different blends, though the car manufacturers have a big say. The idea is that service stations can sell blended Bioethanol (say 5% bioethanol, 95% petrol) without branding it as such. This would allow a bioethanol manufacturing industry to get established. The problem is to what blend will car manufacturers will maintain their guarantees too.

Pros – Petrol is the norm in this world of ours – It is easy to convert petrol engines to bioethanol

Cons – Expense – Starchy crops are really expensive, fermentation and distillation plants are really expensive. Also very large factories are needed to effectively produce the fuel


Replacement for – Diesel

Made from – Rapeseed, palm, algae. The oil from these crops is “esterified” and mixed with regular diesel

Availability – Same as bioethanol really

Pros –Easier to make than bioethanol, diesel vehicles are generally larger, and so more economic to modify.

Cons –Rapeseed is not a standard crop.

Pure Plant Oil

Pure plant oil (PPO) is the oil that can be extracted from suitable vegetable matter, such as rapeseed or palm. When you hear about people using cooking oil from restaurants, this is what they’re talking about. The problem is that it is solid, or at least very thick, at room temperature, so it needs to be heated before it can be used. This means fitting a modification to a regular engine to heat the oil in the fuel tank.


Energy Wasting Day

June 18, 2008

Solar Thermal Panels – Flat bed or Evacuated Tubes

June 16, 2008

Solar Thermal Panels or Solar Water Heaters come in two main types… Flat bed panels and evacuated tubes. So which are better?

Well first of all, the theory behind the two systems is much the same. See this post for more. Solar collectors (which are essentially just thin pieces of metal) absorb energy from the sun, and transform this energy into heat. This heat is then transferred to the houses hot water cylinder where it provides useful hot water.

The main difference between two technologies refers to the way the metal collectors are configured.

Flat Bed Panels are a simpler technology. A thin panel of metal, usually painted black, is positioned just below a pane of glass. The reason for the glass is to prevent heat escaping into the air, and so maximise the amount of heat transferred into the hot water cylinder.

The benefits of the system

Flat bed plates are relatively cheap

When the sun is shining directly at the panels, they have the maximum plate surface area exposed to the sun, and so achieve the maximum possible

They look very inoffensive

The drawbacks of the system

At times when they are not receiving direct sun, they’re not as effective evacuated tubes

If the panel is damaged, it will have a very significant effect on efficiency of the system

Evacuated Tubes are a more complicated technology. Thin strips of twisted metal are positioned in the centre of a vacuum filled tube. The vacuum tube means conduction losses are reduced, while the glass acts to reduce convection losses. The idea behind the twist on the metal is that it means part of the panel is at the correct angle to receive the maximum energy from the sun, and therefore providing energy to the cylinder at lower sunlight times of the year.

The benefits of the system

Provide a significant amount of energy to the cylinder at all times of year

If one of the tubes is damaged, it will have little effect on efficiency of the others. Also it is easy to change one tube if necessary

The drawbacks of the system

More expensive than flat bed systems

They are less effective during times of direct sunlight. Does it matter?

They are more remarkable looking than flatbed panels. A bad thing?

Energy Saving Driving Tips 3 – Aggressive Driving

June 15, 2008

Truth is, if the accelerator was called the fuel consumption accelerator, it would be more accurate. Also, when you brake, you are basically just wasting energy you’ve paid to put into the car. A less aggressive, energy conscious driving style could reduce your fuel consumption by 10%.

Cooling down in the office – too hot at work 1 – Blinds/Shades

June 11, 2008

Which blinds do you use?

At this time of the year, the amount of heat being generated in your house by sunlight is far more troublesome than the benefits from lighting it gives. This means that you would actually be more energy efficient during the summer if you had no windows. As this isn’t a possibility, the solution is blinds/shades. Lots of people think blinds are just there to cut our glare on computer screens, but no… they also can have a significant role on keeping heat out. Different blinds have very different effectiveness at this though.

There are two main types of blinds that people use. The first type are simply a sheet of fabric rolled up above the window which can be lowered as required to stop the light as required. The second use a series of parallel shades (louvers) which can be rotated to an angle suitable to reflect light out of the room, or onto the ceiling of the office, as required.

Well from the point of view of cooling your office down, the idea is this… reflect light back out of the office. If you allow it to be absorbed in the office, the majority of it will be transformed into heat, which is the problem.

So… The principles are

Dark blinds are bad, as dark things absorb more light, and so convert it to heat, that bright ones do

Shiny/reflective things are better as they are better at reflecting the light. Mirror would be best

So with these ideas in mind

Parallel shades are better as they are more reflective.

Dark, or perforated shades are a bad idea.

The wider the parallel shade the better, as it has more chance of reflecting out the sunlight