Marian Finucane Saturday 23 February 2013
Duncan Stewart - energy efficient homes
Duncan joins us in studio to tell us how you can make your home more energy-efficient.
HOW TO MAKE YOUR HOME MORE ENERGY EFFICIENT
Let’s start from the top of your house and make your way down to the bottom.
ATTICS - Insulate your attic. It will cost between E200 to E300 and make a huge change. It could shave 20% off your heating bill and move your BER rating up the scale.
Make sure masks and gloves are used when laying fibreglass.
It’s very important to lay an airtight membrane (polythene) under the insulation. It prevents vapours from rising from the room below and driving up and hitting the cold air which can cause dampness. If you have not already put down an airtight membrane you still can.
The trap door should also be draft sealed and insulated on top of it.
Keep all electric wires above the insulation – lag all pipes and cold water storage.
You have to invest in the short term in insulation and draft proofing/ sealing in order to benefit in the long term. Over the winter look at how energy is used in the home and the cost of it. Try and make projections for the next 10 years.
CONSERVE ENERGY WHERE YOU CAN
Keep temperatures within controllable levels which you can afford. Thermostats on radiators are extremely efficient when it comes to this.
It’s much better to have heat on (even at a low level) in all rooms even in rooms you are not using. If you are only heating downstairs but not upstairs – the rooms upstairs will get very cold. If the temperatures then fall below the dew point you’ll get condensation and dampness. (The dew point is a water-to-air saturation temperature. The dew point is associated with relative humidity. A high relative humidity indicates that the dew point is closer to the current air temperature).
DRAFT PROOFING AND SEALING YOUR HOME
You can do this in lots of way from external insulation of the walls to installing triple glazed windows. Whichever way you go make sure you still have ventilation in all rooms. This will keep humidity levels down and therefore avoid mould growth which can cause respiratory issues. It will also keep radon and carbon monoxide levels down. At night keep internal doors open and the windows in the room open a little bit where people are sleeping.
If you are going to have an airtight house you need heat recovery ventilation. Fresh air is drawn in through a pipe in the vent that heats the air in the heat exchange unit. So the cold air coming in gets pre-heated by the exhaust air going out which means there is less energy wasted.
While no one likes drafts, you have to keep a balance between draft proofing and ventilating a room. In cold weather people tend to close of vents, which causes big health issues.
Sealing and Draft-Proofing your floors
About 10% of heat loss from an average home is through the ground floor. You could cut your energy bills by insulating your floor (sealing the gaps between floors and skirting boards to reduce draughts).
There are different ways to draft proof. It all depends on the type of flooring you have.
Stripped Floorboards - Cold air naturally circulates below ground floor floorboards, and the small gaps between boards in an average-sized room add up to the equivalent of a small window. A simple rug can also block draughts.
Carpet – add an insulating layer using a fibreboard underlay or polyfoam board.
Gaps and draughts around skirting boards and floors are simple to fix yourself with a tube of sealant bought from any DIY store. Floorboards will rot without adequate ventilation, though, so don't block under-floor airbricks in your outside walls.
Older homes are more likely to have suspended timber floors. Timber floors can be insulated by lifting the floorboards and laying mineral wool insulation supported by netting between the joists.
Many homes – especially newer homes - will have a ground floor made of solid concrete. This can be insulated If it needs to be replaced, or can have rigid insulation laid on top.
You don't need to insulate the floors of upstairs rooms in your house if they're above heated spaces (like the living room). But you should think about insulating any floors that are above unheated spaces such as garages, as you could be losing a lot of heat through those. (www.energytrust.co.uk)
CHIMNEYS / FIREPLACES
Install a wood burning stove instead of burning coal in an open fire. With the latter four fifths of the heat goes up the chimney whereas with a wood burning stove only 25% does.
A wood burning stove will cost between E500 to E2000 to install – the price depends on what you are doing.
What about chimney balloons for blocking cold air coming down the chimney?
There are three ways to insulate a wall – cavity insulation (in the middle), internal insulation (inside) or external (outside) insulation. Each method has its own strengths and weaknesses.
Cavity wall insulation is the cheapest. It’s when you pump insulation material between the 60mm gap between two walls built side by side.
Internal insulation is where you attach insulation to the inside of a wall eg about 100mm of insulation material onto the wall finished with a plaster. This is cheaper than external insulation but necessitates redecorating.
External wall insulation - this is where you wrap the entire house in an insulating blanket. It tends to be about 110 mm thick and is composed of an insulating layer and a coloured render or brick finish. It is applied from the outside so there are no problems with thermal bridges, no loss of space and no need to redecorate. By insulating the outside you make the entire house a single thermal block, like a storage heater. In this way the house stays warm in winter and cool in summer. When the external insulation is being fitted down pipes may have to be moved and window sills extended. So there can be a fair amount of work involved and this is the most expensive solution. But when the project is complete you get a completely fresh facade and the best thermal properties of the three systems. .
All three systems are eligible for grants under Sustainable Energy Ireland’s Home Energy Saving Scheme. The value of the grant varies according to the system chosen.
Behavioural changes can also make a big difference to your energy bills.
Duncan is all for people putting on extra layers in the home if they are feeling cold to save money and not putting the heating on.
Conserve Energy where you can – keep temperatures within controllable levels.
Do not use electricity to heat your home (unless of course it is being used for a heat pump). It’s very expensive.