Share
David Wilson
The wayward wind
Did you know that around a third of all the heat lost in an un-insulated home is through the walls and that just by insulating your cavity walls you can reduce heat loss and save money on your fuel bills?
Needless to say, as soon as I found out, I was quick to call in the folks from the local cavity wall insulation company. After all, not only would the insulation help me heat my home more efficiently, using less energy would also reduce the carbon-dioxide emissions from my gas boiler. And, being a bit of an environmentalist, I liked the idea of doing my bit to slow down the effects of climate change.
Before performing the work, a chap turned up to conduct a survey of the house. While he was quick to re-iterate all of the financial and environmental benefits that the work would bring, he also told me that, as part of new regulations, it would be necessary for his team to fit a vent through the cavity wall before performing the insulation – all because I had an open fireplace in my living room.
The vent, he explained, was necessary to eliminate any risk of a build-up of carbon monoxide, which could possibly become a problem due to insufficient airflow.
A few days later, the cavity wall folks turned up in a rather large vehicle and duly set to work. First off they created a large hole in the wall with an auger and installed the vent, after which they drilled smaller holes through which they filled the cavity walls, injecting each hole in turn, starting at the bottom and working their way up. It was a highly efficient process and took the two gentlemen just two hours to complete.
I’m sure you can imagine how much I was looking forward to living in a much warmer house after the work had been done. But when the winter winds started to blow, the effect of the new vent that had been installed in the living room became apparent - the bitterly cold wind was howling in at an unprecedented rate. It couldn’t have been any worse if I had left a window in the room wide open.
Clearly, the new vent was doing little to lower my fuel bills, so against the advice of the insulation company, who insisted that the vent be open at all times, I found a large piece of cardboard, which I used to cover it up, preventing any more of the cold air from racing around the room.
I’m pleased to report that the house is now a lot cosier than it was before. And the energy savings that I have made have been considerable.
However, the logic of installing an open vent as part of an energy-saving process still troubles me. Indeed, it seems completely contradictory – the equivalent of designing a circuit that can run at 3GHz and then throttling it back to half speed before shipping it to a customer. I ask you, what engineer in his right mind would see the logic of that?
Dave Wilson
Editor, Electronicstalk
Dave’s comments form part of the weekly Electronicstalk newsletter, which also includes a round-up of the latest electronic products and services for engineers. To subscribe click here
Readers' comments (5)
Dave Bethell | 4 Mar 2010 5:11 pm
Ahah, the perennial problem with uber-sealed accommodation and heating systems or air-conditioning.
I live in an 18th century house with no cavity walls, mainly single glazing (Grade 2 listed house in a conservation area) and a mere 4" of loft insulation as the joists are only that deep. Nothing really fits anywhere and we get loads of fresh air. Only the rooms that are used regularly are heated, one does not want to hang about in the bedroom out of bed too long on cold nights, but we also wear appropriate clothing.
Our hot water tank temperature is sensible (if it's uncomfortable to place your hand under the running hot water tap it's too hot !!!) and we never empty the (shared) bath until the water has turned 'cold'. We'll never die of CO poisoning and our fuel bills are not at all bad for the property volume.
Oh, and by the way, I sit next to a window at work (and walk between work and home ...) so that I can always get fresh air, whatever the damned air-con thinks it should be doing ... usually making the room too warm by far !!!
Unsuitable or offensive? Report this comment
Rafael Ospino | 4 Mar 2010 5:53 pm
I agree with the editor about the lack of logic, but to both conserve energy, maintain a healthy air circulation and comply with regulations you should make the final investment; a rotating heat exchanger. This way you could use the energy in the already heated room air to warm the outdoor air to an almost equal temperature.
Unsuitable or offensive? Report this comment
Ron Neale | 4 Mar 2010 5:53 pm
Al I can say is "SNAP plus 1". I had exactly the same experience, except because we have fireplaces in what are two arch connected rooms we were charged for two vents (£200).
My pleas the that both fire places have independent underfloor air feeds was ignored. As was the fact that the fireplaces have been in use for 50 years without any ill effect.
Within hours of the fitters departing both vents were blocked with neat covers and will be filled in when the summer arrives and before the wasps take up residence.
As you say David it's like having a broadband connection that promises Multi-Mega performance and and hardly delivers a Mega bit. I guess somebody fitted a bit vent to mine at no charge.
Unsuitable or offensive? Report this comment
Tony | 5 Mar 2010 12:46 pm
Back in the day I worked for a large UK computer company in the USSR. We sold them a computer which was a re-engineer of our top of the range model to slow the system down to come in below the USA export limitations. In the UK we sold two models that were different by 1 wire and 50% in speed. It is an accepted method of engineering a range of machines - or used to be!
Unsuitable or offensive? Report this comment
John B | 8 Mar 2010 11:15 am
Not suprised you were cold. Whilst in Canada, I was informed that in winter a hole in the loft the size of a pencil loses 40,000 cubic feet of warm air. A heat exchanger is the only sensible option.
Unsuitable or offensive? Report this comment