[GSBN] The mechanical ventilation debate

[Feile Butler]

I've been thinking about why has the mechanical ventilation debate been getting under everyone's skin so much. I think Robert Riversong's post echoes how I feel about it.

"what we now think of as a house has evolved from simple shelter to a highly-engineered machine that requires "operation" by its occupants in order to maintain a comfortable and healthy indoor environment."

John Straube made the point that we are all happy to use electricity for our fridges and computers, so why not our mechanical ventilation systems? 

We don't, in fact, have a fridge. We wanted to prove we didn't need one with what I like to call "Granny Wisdom". So much of my grandparents' generation worked in harmony with their enviroment and put the available local resources to work in ingenious ways. So we have a stone lined cupboard buried in a north facing cob wall, with a series of vents at the back. We have simple 90 degree plumbing elbows attached to the vents, which we manually rotate to capture the optimum flow of air (although, to be honest - we only need to worry about that for a few days in the summer). Now, this might not work in California, but it works perfectly in Ireland (our local environment). We have never had a problem with soured milk or spoiled food. 

"That we need mechanical ventilation in our homes today is a result of our need for increasing amounts of insulation which is the result of our increasing population and increasing demand for energy, which is in part a result of our ever-growing sense of need for consumption, comfort and control, which is a result of a mindset or cultural paradigm that is based on the myth of progress and a blind faith in technological "solutions" to problems created by the last generation of technological "solutions". - Robert Riversong

We are now starting to design/create houses that must be mechanised in order to be safely occupied. If my electric oven doesn't work in a power cut, I can cook food on my gas stove-top or I can barbeque. If my lights don't work, I can use candles. If I can't heat my hot water, it's inconvenient - but it will not compromise my health. However, if my mechanical venitlation unit fails for a period of time, then my health will be compromised. My shelter becomes a hostile environment. This is a significant line to cross.

I accept that many of the old leaky houses also had health problems associated with them - damp, spores, toxic mould. The issues causing many of these problems were not understood at the time these buildings were built. However, we are now seeking to design buildings that we know will be unhealthy if one component is not properly used, serviced or fails. And human nature being human nature, this component is likely not to be serviced or properly used. I have heard of plenty of people having their system running on the wrong setting, or turning it off altogether. 

One of things that excites me most about natural building materials is that they accept nature and work in harmony with it. They don't try to combat it. They get wet, but they can dry out again. But building an environment that can become poisonous for its occupants unless certain technology has been installed and is regularly serviced (technology that requires expertise to install/repair beyond that possessed by the average homeowner) seems to jar with many of the philosophies behind natural building.

"We have come to substitute control for adaptation, which was the driving force for biological and cultural evolution for 3.5 billion years on Earth."- Robert Riversong

I grew up in a country where air-conditioning was unheard of. Maybe, if some of you have grown-up with air-conditioning, it seems like a progressive step to make much more efficient climate control units. But for me, crossing this line causes me concern.

Have we gone so far that it is too much to expect our clients to wear an extra jumper in winter? Maybe we have. But I'd like to see a bit more Granny Wisdom in the world again.

Cheers

Feile


Féile Butler
MRIAI B.Arch Dip. Arch Conservation Grade III
Mud and Wood
Grange Beg, Skreen, Co. Sligo, Ireland

T:  +353 (0) 71 930 0488 
M: +353 (0) 86 806 8382
E : feile at mudandwood.com
W: www.mudandwood.com
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