One thing that I found interesting about it was that it was compressed on the roll, and after laying out, it expanded up to a thickness of about 2″ (50mm). At the time, this was quite normal, and with this additional layer, we had increased the insulation to 4″ (100mm).

Nowadays, the Energy Saving Trust recommends a minimum loft insulation thickness of 10.6″ (270mm) – more than 2.5 times what we had in our house.

As [Read more...]]]> I recall helping my father fit additional loft insulation to our house when I was a child. The material we used was an orange, fibreglass matting on a roll. It was really nasty stuff to handle. If you got any of it on your skin, it would be very irritating so we wore overalls, long sleeves and gloves. We also took care to wear masks so that we didn’t breathe the fibres.

One thing that I found interesting about it was that it was compressed on the roll, and after laying out, it expanded up to a thickness of about 2″ (50mm). At the time, this was quite normal, and with this additional layer, we had increased the insulation to 4″ (100mm).

Nowadays, the Energy Saving Trust recommends a minimum loft insulation thickness of 10.6″ (270mm) – more than 2.5 times what we had in our house.

As much as 25% of the heat in your house can be lost through the roof. Warm air rises, so it stands to reason that the top of the house is going to be where the warm air is going to be lost. Insulating your loft space to the recommended amount will reduce the amount of heat loss considerably.

The amount of money you save as a result of insulating your home depends on a lot of factors, but you should be able to see a payback time of about 3 years if you upgrade to the recommended thickness of insulation. For home improvement (not new builds) you can get subsidies on loft insulation. For example, Wickes, my local supplier, is currently selling 3 for the price of 2, subsidised by EDF the energy company.

Insulating Blankets

Insulating Blankets are a fibrous blanket on a roll, similar to the fibreglass material I used as a child. Today, it is often made from a spun mineral material which is nowhere near as irritating as the fibre-glass. It is available in various thicknesses and can be used for new insulation or to top-up whatever insulation you have already.

Fitting the blanket is simplicity itself as the rolls split down into narrow strips that fit in the space between the joists in your roof space. Place one end of the roll at the wall in the space between the joists and unroll it. If the roll is not long enough, simply place the beginning of the next roll where the first one ends and continue. If the piece is too long, it can be cut with a sharp knife.

Start at one end of the roof space and progress from one joist to the next until the entire space has been insulated.

Take care!
Take care to step only on the joists when working in the roof space. If you stand on the spaces between the joists, you are likely to end up going through the ceiling of the room below.

I invested in a few packs of loft boards which leave loose up in the loft. I can move them around, placing them across the joists wherever I am working. This allows me to walk around safely without having to balance on the joists themselves.

Something else you might also want to think about is light. Most lofts don’t have a light fitted, so you will need a powerful torch or an inspection lamp on a long lead. Don’t try to work in the dark.

Insulating Slabs
If you want to use the loft space – perhaps you are converting the loft to a room – putting insulation between the joists will keep the rest of your house warm, but will make the loft space colder in winter. Therefore, you will neet to fit insulation between the rafters instead. (rafters are the wooden beams that form the sloping roof and support the tiles – joists are horizontal)

Insulating slabs are made of a similar material to the blanket rolls, but they are compressed into solid slabs. These can be cut to size with a sharp knife and pushed into the spaces between the rafters. Cut them to be a tight fit within the space and they will hold themselves in place.

Also available for the same purpose are expanded polystyrene foam blocks that are made in such a way that they can be squeezed into the space between rafters and they expand once in place to hold themselves in.

On my Victorian house, I found that the spaces between the joists and the spaces between the rafters were not consistent and don’t fit the width of modern materials, but it was possible to squeeze them in or cut them to size.

Warning
Insulating your loft will save you money as you waste less heat. However, by stopping heat-loss into your loft, you will make that space colder in the winter. If you have any water pipes or a cold-water tank in your loft, please consider the fact that a colder loft will increase the risk of damage by freezing. So you should lag your pipes and the tank appropriately.

But consider what happens when you take a shower. The incoming water might be 10 degrees Celsius (50 F). The temperature is then raised to say, 43 degrees Celsius (110 F). The water cascades over your body and then goes down the drain.

It is estimated that about 95% of the energy used to heat the water to a comfortable temperature is simply going down the plughole.

If you have an electric shower unit, you could actually recover some of that energy. An electric shower connects directly to the cold water supply. A very powerful heating element (typically 8 or 9 kW) then rapidly heats the [Read more...]]]> You often hear statistics about showers being more efficient than baths. A bath usually uses a lot more water than a shower, so you’re not only using a lot more fresh water, you’re using a lot more energy to heat that extra water.

But consider what happens when you take a shower. The incoming water might be 10 degrees Celsius (50 F). The temperature is then raised to say, 43 degrees Celsius (110 F). The water cascades over your body and then goes down the drain.

It is estimated that about 95% of the energy used to heat the water to a comfortable temperature is simply going down the plughole.

If you have an electric shower unit, you could actually recover some of that energy.
An electric shower connects directly to the cold water supply. A very powerful heating element (typically 8 or 9 kW) then rapidly heats the water to produce an almost instant supply of hot water.
In the winter time, incoming water may be colder than in the summer time, so you need to use more energy to heat the water to the required temperature.

So how can we recover the wasted energy?
The answer is a simple heat exchanger, which transfers the heat from the waste water to the incoming water supply.

Basically what happens is this: the cold water supply runs through a pipe that either coils around the waste pipe, or runs through the inside of the waste pipe.
As the shower starts to flow and hot water goes down the waste pipe, it starts to heat up the cold water inlet pipe. Heat has been transferred from the waste to the cold supply.
The supply water is now several degrees warmer than it was before, so the shower unit needs to use less electricity to heat the water up.

Heat exchangers of this type are commercially available, but it wouldn’t be beyond the capabililties of a competent DIY enthusiast to make one for himself.

You would need to ensure that the cold water supply had a check-valve to stop warmed water going back to the cold supply.

Your shower unit would also need to be thermostatically controlled. A standard shower unit would simply apply the same amount of energy to the warmer water, resulting in scaldingly hot water output. You might end up having to adjust the temperature manually several times during a shower to compensate for the changes in temperature.

Personally, I didn’t know it was Energy Saving Day until I read about it on the BBC News website at lunchtime – half-way into the day. I asked my colleagues if they knew if it was Energy Saving Day, and they didn’t know either.

We weren’t alone in our ignorance – comments on the BBC’s website indicated that other people didn’t know about it either.

Looks like the publicity department of the organisation that thought up this idea took the concept to heart and consumed no energy whatsoever in telling people about it.

In the home, saving energy means saving money, and one of the quickest and easiest ways to save is in lighting.

Most homes use incandescent bulbs for their lighting.  These are the standard bulb with a coiled filament that glows when you apply electricity to it.

But did you know that these have an energy efficiency of only about 2%?  That means for all the energy you feed into it, only one fiftieth of that energy is converted to light energy.  The rest is mainly heat.  That’s why light bulbs get so hot.

The new Compact Fluorescent Lamps (CFLs) on the other hand have an energy efficiency of between 7% and 10%.  That still doesn’t sound very good, but what it does mean is that to get the same amount of light out of it, you only need to supply it with between one quarter [Read more...]]]> Everyone is talking about saving energy, and quite rightly too.

In the home, saving energy means saving money, and one of the quickest and easiest ways to save is in lighting.

Most homes use incandescent bulbs for their lighting.  These are the standard bulb with a coiled filament that glows when you apply electricity to it.

But did you know that these have an energy efficiency of only about 2%?  That means for all the energy you feed into it, only one fiftieth of that energy is converted to light energy.  The rest is mainly heat.  That’s why light bulbs get so hot.

The new Compact Fluorescent Lamps (CFLs) on the other hand have an energy efficiency of between 7% and 10%.  That still doesn’t sound very good, but what it does mean is that to get the same amount of light out of it, you only need to supply it with between one quarter and one fifth of the energy.

Now that we’ve established that they use a lot less energy, what about the cost?

The prices of CFLs has come down rapidly in the last year or so, and they are now about 3 times the price of conventional incandescent bulbs.  Furthermore, they last about 10 times longer, so you don’t need to replace them quite as often.  So in real terms, they actually cost about one third of the price of conventional bulbs.

Consider that in the winter, you might leave a light on from 4pm to 11pm (7 hours).  Let’s say that it costs 1 penny (UK) to run a 100 Watt incandescent bulb for 1 hour.

In 1 month, it will have cost about £2.97 to run that light bulb.  For the four months November to February, that would come to £11.88.

A CFL of the same light output uses just 22 Watts.  Over the same period, that would cost £2.62, a saving of £9.26.  That’s enough to buy 3 CFLs.

Now that’s for just one lightbulb.  How many more do you use in your house?  You could easily save up to £100 a year by switching.

Don’t wait until your incandescent bulbs have blown before replacing them with CFLs - it’s cheaper to throw away your incandescent bulbs now!

In the UK, incandescent bulbs will be withdrawn from sale in 2012.  You don’t need to wait until then to switch over.  Do it now and save some money.