[GSBN] The Mechanical Ventilation Debate

[John Straube]

On 2013-03-22, at 9:14 AM, "Feile Butler" <feile at mudandwood.com> wrote:

> I also know the mechanical ventilation debate has opened up a much bigger discussion than the original posts intended. We are looking at this from different angles. 
Exactly. I said this.  You want social change, I am trying to deal with the same environmental problem and believe massive change is not needed but some would sure be helpful!

> The big wheel is turning. You say that 99% of people want/need passivehaus housing. The supposition is that this is the direction that the construction industry/public desire is going and it has gathered so much momentum that it cannot be stopped.
I did not say people want and need PassivHaus housing.  I said people want comfortable housing, comfort of their own definition. And they usually want healthy, durable, affordable housing too.  PassivHaus is one rather extreme option, but it is far from the only one. I think it is too complex and intensive.

> That we don't have much of a choice today in the necessity of mechanical ventilation in well-insulated homes is evidence of the cul-de-sac that our "progress" has driven us into.
You dont need to use mechanical ventilation. You could use passive ventilation if it works.  It is just harder and more intensive of resources in most cases.  Progress has also created much larger problems, like the cul-de-sac that is indoor plumbing (what a huge pain all those watertight, properly sloped pipes are, and then the treatment systems, whew!, lets get rid of those!"), fridges, hot water, and electric lights (the complexity of all that wiring, the risk of electrocution and fires, all the regulation to avoid the same, I say strip out that progress from our walls).

> I suppose I am questioning (maybe naively and idealistically) whether there can be a shift in societal expectation?
This is a very valid and useful discussion. It is not about ventilation or airtightness.  
Shifting people to live close to where they work and study would be a massive energy saving.  That is a societal change worth pursuing.  
Ventilation is not. The use of a 20W fan for ventilation is a tiny tiny bit of a household energy and resource use, not even a rounding error, rather a 0.1% or so value.  Once you run it through the added complexity of an HRV it actually reduces household energy use by about 1 or 2%.  

>  
> I know when people started building with straw bales, the wider masses thought they were crazy. It was so simple and so cheap - it couldn't be possible!!! Now it is a well-established, well-researched method of building. Just because the "mad" 1% were doing it, didn't put them off. And with time it continues to gain a bigger and bigger foothold in the mainstream.
Exactly, just like airtightness and insulation was long resisted, and now that there examples and they show how much healthier and more comfortable houses can be while producing less environmental damage it is really catching on! Not yet in milder climates, but in cold climates and climates with expensive energy, it is now almost normal.  This has been more successful, because it is easier to deploy widely, than straw bale.
>  
> A lot of our work is about bringing people back to simplicity - to start with the people - to change their perceptions - and then a different type of building becomes possible. This type of work may only be affecting the 1% at the moment (maybe even less), but there is potential for it to grow. I suppose I am trying to say that it is important that we do keep other options open - that there is not just one holy grail. (And I accept that this is not what the original thread was about).
> 
Thank you Feile for engaging in the conversation.
I really do believe some social change will be needed, and people in the SB world are doing some of this. You are much more likely at making this change happen that I am.  I just dont think ventilation even rates in the scale of the conversation, since this is not really a big complexity, cost, effort, etc. and it does have a proven track record of success.  Lets focus the social change on things that really matter to the environment and dont have easy fixes, like driving, like using fridges (a major energy user in many household), etc etc.

John Straube
www.JohnStraube.com