Grand Designs - 18th Feb
Discussion
Passivhaus, such a lovely word. Why is anything so much more impressive and believable when it is said in German. Vorsprung durch Technik, Poggenpohl, Mercedes-Benz? Here we go. Let's all have mini HVAC systems with heat recovery and little ducts running all over the house. It will soon be law. Wait and see. And when we have done all this thinking we will be just like the Germans, the Germans will laugh at us for our gullibility. These guys have done nothing repeat nothing new. They have created a brand.
All I would say is
Firstly, don't suspend common sense. The world is not being heated up by man made carbon dioxide. That is pure bulls
t.
Secondly if you overheat your house by any means it is unhealthy.
Thirdly if you deprive yourself and your house of a reasonable supply of fresh air, your health is going to deteriorate, and ducted air is second choice at best. These things do need cleaning, and how much is that going to cost when you have to call in the hygiene squad, as many food factories now have to do.
Fourthly, there is nothing to stop you recovering heat from a centralised warm air stack and there is nothing to stop you getting all the power you need from photovoltaic panels and all the heat you need and more from ground sourced heat pumps. So what good is making your building reasonably airtight (because that is all it is ever going to be) going to do for you. There is no reason other than initial cost and some care that you cannot build a house which creates more energy than it consumes, that modulates both summer and winter conditions in any part of Europe, provided the occupants themselves recognise that there is a difference between summer and winter.
So what do you need to pay for Passivhaus accreditation for? To get the gold star from teacher? Why not stick a big three pointed star on the roof and be done?
All I would say is
Firstly, don't suspend common sense. The world is not being heated up by man made carbon dioxide. That is pure bulls
t.Secondly if you overheat your house by any means it is unhealthy.
Thirdly if you deprive yourself and your house of a reasonable supply of fresh air, your health is going to deteriorate, and ducted air is second choice at best. These things do need cleaning, and how much is that going to cost when you have to call in the hygiene squad, as many food factories now have to do.
Fourthly, there is nothing to stop you recovering heat from a centralised warm air stack and there is nothing to stop you getting all the power you need from photovoltaic panels and all the heat you need and more from ground sourced heat pumps. So what good is making your building reasonably airtight (because that is all it is ever going to be) going to do for you. There is no reason other than initial cost and some care that you cannot build a house which creates more energy than it consumes, that modulates both summer and winter conditions in any part of Europe, provided the occupants themselves recognise that there is a difference between summer and winter.
So what do you need to pay for Passivhaus accreditation for? To get the gold star from teacher? Why not stick a big three pointed star on the roof and be done?
I see what you mean about whether the Passivhaus rating was necessary for a home. The guy is an architect though, he's built his own house to show what he can do, and got the build on TV. Its a great way of advertising your skills to the world. The roof collapse wasn't ideal but it was explained as being because that part was 1 layer thick and it was a point pressure from being leaned on. He may have come across as a lively character with the 'high fives' etc, but professionally he knew what he was talking about and proved he could build an unconventional design to very high standards to get that rating.
cardigankid said:
Firstly, don't suspend common sense. The world is not being heated up by man made carbon dioxide. That is pure bullst.
Umm... there are a lot of reasons for building this way besides worrying about CO2. Better air quality and lower heating bills sound good enough to me.t.cardigankid said:
Secondly if you overheat your house by any means it is unhealthy.
Most passive houses are underheated if anything. Often the bedrooms are unheated, and allowed to settle at a naturally lower temperature than the rest of the house. That's a whole lot healthier than modern centrally heated homes that often have the bedrooms stiflingly hot.cardigankid said:
Thirdly if you deprive yourself and your house of a reasonable supply of fresh air, your health is going to deteriorate, and ducted air is second choice at best. These things do need cleaning, and how much is that going to cost when you have to call in the hygiene squad, as many food factories now have to do.
What do food factories have to do with this? Have you been anywhere near a modern mechanical heat recovery and ventilation system?cardigankid said:
Fourthly, there is nothing to stop you recovering heat from a centralised warm air stack and there is nothing to stop you getting all the power you need from photovoltaic panels and all the heat you need and more from ground sourced heat pumps. So what good is making your building reasonably airtight (because that is all it is ever going to be) going to do for you.
Yes, you can do all that, but it's rather a weird way to go about heating your house. Centralised warm air stacks (ie. passive stack ventilation) suffer from controllability issues - they vent more in the winter or on windy days, just when you want them to vent less. They're also not practicable in some house designs - for instance where you cannot get enough height for a stack to work effectively.Heating from PV panels and heat pumps is drastically inefficient, and works the least well just when you need it - in the winter. A better solution is to go for passive solar gain (cutting out all that messy electricity) - and if you really want to make it work well, go for an interseasonal thermal store. Personally I think that's all a bit impractical for the average home, but not out of place in a grand design.
Reasonably air tight is good enough to drastically reduce your heating bills. Normal methods of construction are extremely poor, so it doesn't require NASA style sealing to make a very worthwhile difference to the heat your house looses every minute.
cardigankid said:
So what do you need to pay for Passivhaus accreditation for? To get the gold star from teacher? Why not stick a big three pointed star on the roof and be done?
As a self builder, you're probably right. As a builder or house buyer, something like Passivehaus accreditation is a way of establishing what you're spending your extra money on, and that the house you're ending up with will genuinely cost less to run.In the UK, we're doing our own (botched) version of this, the 'Code for Sustainable Homes'. You can get CSH levels 1-6. By the time you get to level 6 you have something that is very similar in efficiency to PassiveHaus. In fact, the way the CSH levels are assessed, it's hard to get to level 6 without making many of the same technical decisions as PassiveHaus - so Mechanical ventilation and so on.
Nothing wrong with having a label for it. Just like having ratings on your Fridge, or MPG figures for your car, don't you want to know what the running costs for your nice new home are likely to be?
Anyway, here's my quick and dirty history of building:
1. We learned to build weathertight houses out of brick and cement. They were still draughty, but we slept with lots of blankets and night caps to keep our ears warm.
2. Sometime in the middle of last century, we came up with central heating systems for the masses, and drastically improved air tightness so that the heating system stood a chance.
3. Many of the newly draught proofed homes turned out to be unhealthy because we many builders and home owners didn't understand the consequences of loosing ventilation. Mould and mildew covered the land.
(I think it was at around this point that cardigan kid was learning building tech).
4. Architects started coming up with ways to combine the benefit of central heating with a home that was properly ventilated. Passive stack was rediscovered, and mechanical ventilation was developed to the point where in many homes in Canada and central Europe it's seen as standard. There are many variations on the theme, and building tech is still being refined. There are ongoing arguments about the relative merits of thermal mass, solar gain and other elements in the energy balance of your home. New materials and building techniques are becoming available that allow us to properly control the environment in our homes in a way that simply wasn't available until recently.
cardigankid said:
you could do worse than look at the St. Pancras Hotel, designed by Sir GG Scott in about 1870.
scotal said:
cardigankid said:
Curious you should mention St Pancras, because that is a building with genuine passive ventilation, and designed in about 1870.
Lemme guess, the big hole in the end where the trains go in and out? 
scotal said:
V8mate said:
scotal said:
cardigankid said:
No, you cock, its the hotel, where the stairwells at the end of each corridor are designed as natural warm air stacks.
Ahhh. I went in there on a tour before they started work on it.... not once did they mention that. You're interesting. ETa If a little brusque.
Andy M said:
The car port:
for their green Mk IV astra - nicesleep envy said:
cardigankid said:
you could do worse than look at the St. Pancras Hotel, designed by Sir GG Scott in about 1870.
scotal said:
cardigankid said:
Curious you should mention St Pancras, because that is a building with genuine passive ventilation, and designed in about 1870.
Lemme guess, the big hole in the end where the trains go in and out? scotal said:
V8mate said:
scotal said:
cardigankid said:
No, you cock, its the hotel, where the stairwells at the end of each corridor are designed as natural warm air stacks.
Ahhh. I went in there on a tour before they started work on it.... not once did they mention that. You're interesting. ETa If a little brusque.Tuna said:
cardigankid said:
Thirdly if you deprive yourself and your house of a reasonable supply of fresh air, your health is going to deteriorate, and ducted air is second choice at best. These things do need cleaning, and how much is that going to cost when you have to call in the hygiene squad, as many food factories now have to do.
What do food factories have to do with this? Have you been anywhere near a modern mechanical heat recovery and ventilation system?And noisy
And complicated
And expensive
And needed electricity to run.
Where as a window doesn't while the idea of mechanical ventilation is great in a new house in a 5 year old house i think it will be a nightmare
scotal said:
V8mate said:
BigBen said:
sleep envy said:
for their green Mk IV astra - nice
Had a Disco 3 at the start of the show which seemed to have disappeared by the end.Ben
thinfourth2 said:
Yes it was in a ship and it was huge
And noisy
And complicated
And expensive
And needed electricity to run.
Where as a window doesn't while the idea of mechanical ventilation is great in a new house in a 5 year old house i think it will be a nightmare
Oh yes, you're right there. If you want to use mechanical ventilation, it's got to be designed in from the start or it'll be of no use to you whatsoever. It's not a fix for an existing standard house, but a way to make a house built to higher standards work well.And noisy
And complicated
And expensive
And needed electricity to run.
Where as a window doesn't while the idea of mechanical ventilation is great in a new house in a 5 year old house i think it will be a nightmare
MHVR units are usually about the size of an aircon box, and sit in the loft/basement out of the way. They will only save on your heating bills if your house is designed to keep the heat in in the first place. If you've got trickle vents in all your windows like most modern buildings, your heat will be escaping before a MHVR unit can rescue it.
Tuna said:
Lots of stuff from his hot air system which I won't trouble to recycle here
I'm not out to argue with you personally, and when it comes down to it, I think that there is really only one key issue between us. You like the idea of a mechanical ventilation system and I don't. Without the HVRC as you describe it, there is no point in making your house airtight. It has no other benefit. I do remember the many mistakes made in the 60's mass housing era, and I would remind you that they were made by people every bit as enthusiastic, intelligent and convinced as you, equipped with lovely books about Modern German Housing too.I don't like it because-
1. It is inflexible, and experience tells me that something inflexible, however clever, is going to be abused.
2. It just isn't technically possible. You will never seal a house 100%, so it is flawed from the off.
3. Whatever jargon you use, even when it is expressed in German, what you describe is not passive it is active, and moving parts fail.
4. It WILL get dirty, and you WONT be able to clean it. This applies to every kind of ducted system anywhere. Clean production areas just happen to be the first area where this has been formally recognised as a problem. Do a tour of a hospital HVAC system that's been in a few years and you will likely be physically sick. And ill people are breathing that stuff.
In short, I don't put polythene bags over my head nor go to work in a frogman's suit, and for the same reason I don't want to live in a sealed box. In both cases I prefer the concept of a loose fit. We all love our Goretex breathable fabrics but for some reason we want to seal our houses. If I have a modern house, and I would like to build one one day, I want to be able to open the whole front up on a nice day, I want adequate heat where I need it, and not when I don't. I want passive heat storage in the structure. I want access to fresh air at will. I never sleep in a bedroom without the window open, and I don't see why I should. I am having an open log fire, and if you or Gordon Brown don't like that you can go and f
k each other. I do not want to pay fuel bills of any type and with the natural technologies and genuinely passive systems now available and constantly becoming more sophisticated I KNOW I can achieve that at reasonable cost. Jesus, right now a well insulated but breathable structure barely needs heated at all. What do we need this additional complication for?I have another reason why I am so concerned about this particular technology. Like chlorinated water and anything else politicians think is good for me, I don't want it shoved down my throat right or wrong. When Mr Chumley Warner gets a hold of this we are going to be made do it - the Building Standards are already headed that way in the teeth of common sense. From a politician's perspective this is a godsend. Next up they will put a CO2 meter in the exhaust flue and start charging us for breathing. And you my friend have swallowed the hook, the line and the sinker.
Edited by cardigankid on Friday 20th February 14:13
cardigankid said:
Yippee! Got the last word. 
Didn't 
Actually, I'm not really arguing with you either. When we first started planning our house, I was also dead against MHVR, but many of my reasons for not trusting or wanting it (moving parts, cost etc.) were just seen as non-issues by people in Canada and Europe where they're in common use. For our specific build it then emerged that it would give us a lot of benefits that we just couldn't achieve easily otherwise.
Ho hum.
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