The importance of Air Tightness for efficiency

HELLO AGAIN, last week in the column I touched on the idea of getting your home sealed. There are a lot of different things that can be done to stop air leakage in your home. People often get caught up in saying "That you need to have ventilation in your home". But the truth is you could nearly dry clothes with the wind blowing through them, well maybe a bit of an exaggeration.

The fact is that any house that is built to modern regulations has wall vents which allow sufficient ventilation; in fact the big hole in the wall is not very efficient, as it is open all the time even when moisture levels are down. It is all the cracks and crevasses that we are trying to seal up. Over the next few weeks I will go into more detail about different products, like chimney closures and different types off air vents.

 

The ultimate way to seal up your home is to get an Air Pressure test done on your home. A fan is fitted in the doorway and connected to a computer to calculate its findings.

 

The way this works is, the house is slightly depressurized after all the vents and chimneys have been sealed up. At this point there are readings taken with diagnostic equipment. An area is then calculated as to the size of your leaks.

You are able to go around with a smoke pencil and locate where the leaks are coming from. You would be surprised where you would find air leaks are able to get in. The technician will be able to show any leaky spots in the house. These Air Leakage tests are a bit expensive but give the best results.

You could get one from around €350; the trick is to have someone there to fix the repairs while the air test is being done, or maybe ask them to seal it for you while they are on site.

The other way is to seal around windows and doors with the silicone gun and hope you seal a certain amount of the leaks. If there is a suspended timber floor it is important to seal around its perimeter. Plasterers rarely ever plaster all the way down to the floor, so it is a good idea to seal your skirting boards as well. Around the window board is another place that normally has air leakage.

It is always a good idea to take a walk around the outside of your house a look where there are any pipes penetrating the walls and seal them with expanding foam. Like inside, run a bead of silicone around the window frame, being careful not to obstruct the windows drip collector.

In building a new house it is definitely worth looking at some of the different products that are available for your type of build. I will write in more detail in the weeks to come as there are many different things to consider.

Keep in mind that there could be savings of about 25-30% on heating bills of air leaky houses.

 

Mandatory Air Pressure Testing

Building regulations, Part L set the minimum standards for Ireland.

New Regulations

New regulations came into effect in July 2008; this makes Air Pressure Test mandatory.

Making Air Pressure Testing mandatory, will make Irish dwellings more energy efficient, therefore reducing fuel consumption and reducing green house gases.

To comply with building regulations, you must air pressure test the building.

 

I got a couple of e-mails from people I hope I can help with these answers:

 

David in Kilkenny asked 'After the coffee percolator has made the coffee, is it cheaper to turn it off and reheat the coffee in the microwave or to leave the percolator on?"

Coffee machines range in power from 800 - 1500 Watts (running cost approx 1.0kW * 1Hour * 0.18c/kWh = 18 cent per hour)

Microwave (Rated at 850W) uses about 1400W in Operation (running cost 1.4kW * 1Hour * 0.18c/kWh = 25 cent per hour, or ½ cent for 1 minute)

So, although both use similar amounts of 'instantaneous' energy, the microwave only uses that energy for a very short time (say, 1-2 minutes to heat coffee). The coffee machine uses energy over a longer period (granted the amount may vary after the coffee is fully heated), but it still uses a lot of power to keep the pot warm.

The simple answer is that it is SIGNIFICANTLY more energy efficient to switch the coffee machine off after making the coffee and reheat the coffee in the microwave.

Seamus in Tipperary asked 'Which uses the most water, a dishwasher or washing dishes by hand?'

A four-year-old 'A' rated dishwasher uses about 22-24 litres of water during each cycle, not all of this water has to be heated. While washing dishes by hand uses as much as 63 litres. These figures are averages taken from a number of different surveys I have researched.

The energy usage would be slightly higher for hand washing dishes, around 2.5kWh due to the high volume of water to be heated. But when using the dish washer; this would be from 1.7-1.8kWh per cycle, on an 'A"'rated machine.

It is important to fill the dish washer for each wash so you get the best value, but do not over fill or you will probably have to wash them again.

So you can say goodbye to the rubber gloves if you want to save water!

Hopefully these helped you out.

I must sign off now but you can check in next week for more energy saving news. Don't forget if you have any questions you can e-mail me on info@thermaloss.ie and I will try to include them in my column