Adverse health affects of a well insulated home

probe

One area the "Home, green home" article which appears in this week's Economist, linked to below, touches on briefly is the need to keep pollutants out of any home built to passive house standards, because the air is changing far less frequently than in a conventional poorly insulated building.

Aside form radon gas, there are emissions from many things brought into the house - they use formaldehyde in so many household things - furniture, glues, sealants, etc.

http://www.economist.com/science/tq/displaystory.cfm?story_id=11999259

Formaldehyde health risks: http://www.epa.gov/ttn/atw/hlthef/formalde.html

Adverse health effects of plastics: http://www.ecologycenter.org/factsheets/plastichealtheffects.html

.probe

air

Any passive house should and most likely would have an efficient HRV system installed. These are typically sized such that thez can change the air in the house many times per hour if desired. Anyone considering a passive house should employ a mechanical engineer to size the system correctly. I would argue that a passive house has the potential to be much much more healthy if used correctly. In winter for example a normal non airtight house would not be getting that much air change with windows etc closed. An equivalent passive house could have the HRV cranked up swapping the air really regularly even though the heat is on and the windows and doors are closed.
As with any new technology, it takes time for people to learn how to use it and there is always potential for misuse.

CJhaughey

probe wrote: »

One area the "Home, green home" article which appears in this week's Economist, linked to below, touches on briefly is the need to keep pollutants out of any home built to passive house standards, because the air is changing far less frequently than in a conventional poorly insulated building.

Just remember that there are a great many poorly insulated but very well sealed houses around now, they can be cold and damp inside from water vapour and condensation this will lead to increased mould/fungal growth and this is as injurious to health as offgassing.
For the record it is impossible to make a passive house without a MHRV system, furthermore most of the countries producing standardised passive houses are well aware of the problem of offgassing and consequently have used materials which have a reduced component of these toxins.

probe

While the house itself could be well engineered from an air management and materials perspective - carpets and furniture (particularly IKEA type stuff - rather than "antiques" that use mortises and proper wood (rather than MDF) brought into a more sealed environment will give off unhealthy emissions which will take longer to clear in a reduced air change environment.

Anyway I wouldn't trust the majority of Irish builders (eg to radon gas proof a building) - most of them have no proper training and lack a professional approach to their work. They can't even lay a concrete sidewalk on the public street and cover it over until the concrete hardens to prevent dogs paws and childrens' graffiti engraving themselves into the surface forever and a day.

If I was having a new house built in Ireland, I'd probably buy a www.huf-haus.com in Germany and have them bring it over and install it on site.

The seldom talked about side of Ireland's property bubble is the awful quality of the construction work done.

.probe

Carlow52

Hopefully the ongoing initiatives to upskill the trades will address the building work quality issue, how to address the unhealthy inputs in to the structure is another issue.

probe

Carlow52 wrote: »

Hopefully the ongoing initiatives to upskill the trades will address the building work quality issue, how to address the unhealthy inputs in to the structure is another issue.

They need to work from the top down too. There are hundreds of builders running companies who have less than a professional approach to their work. Many are total hackers. If the bosses are hackers, no point in wasting money training the workers.

I would also question the quality of the training provided by Fás etc.

Vorsprung durch technik und qualität is missing all around!

.probe

Mossyfields

Manufacturers of Heat recovery ventilation systems , advertise their systems at very high efficiency rates... 98% ?? . I find these figures unbelieveable and have tried to get some independant data... I was unable to find any ........ any help out there ??

air

I thought the same but I spoke to a Mech Engineer friend of mine that specs these systems for buildings all the time and he told me that they really are pretty sh*t hot nowadays alright. He said some of them use fancy membranes and other high tech stuff and that they compete a lot on minimising power consumption etc also - watt hrs/m3 or something similar sticks in my mind.

Mossyfields

thanks Air,
I have had a look at some of these systems at the various shows, perhaps I just dont understand the technology. The systems seem to comprise of two fans , one to expell the air and other to import. There are a series of membranes / baffles which channel the two air flows and in theory transfer the heat from one air stream to another... When I first looked at this I thought the best any system could do was to extract 50% of the heat ( an equalisation of the temprature between the two air flows) but I now understand how better than that can achieved. thanks again

air

No hassle, I know feck all about them myself tbh, just going on the word of someone qualified that I trust. He said that one in a house would cost very little to run over the course of a year.

Energysaver

Mossyfields wrote: »

Manufacturers of Heat recovery ventilation systems , advertise their systems at very high efficiency rates... 98% ?? . I find these figures unbelieveable and have tried to get some independant data... I was unable to find any ........ any help out there ??

I'm not an expert on HRV but I have a HRV system installed in my house. I did a measurement yesterday of the inlet and exhaust air temperatures as follows:

Exhaust from kitchen: 20.1 deg C
Inlet to sitting room: 15.9 deg C
Outside temp: 3.1 deg C

My system claims an efficiency of 97% (I think). I don't know how airtight my house is. Is the efficiency constant with variations in humidity and temperature difference between the inlet/exhaust air? I don't know.

In my test the HRV system has heated the incoming (3.1 deg C) air to 15.9 deg C, which is 4 deg C below the 20.1 deg C exhaust air. Is this 95% efficient? It doesn't appear to be to me, although if you consider the temp in Kelvin then the difference is 289K inlet and 293K exhaust and this is 98% eficient. Fresh air coming in at 15.9 deg C is obviously a lot better than air coming in at 3.1 deg C.

Maybe someone who has expert knowledge in this area could comment.

CJhaughey

When you measured the exhaust and intake temps did you do this inside the house or at the wall vent/intake on the outside of the house?
I am just curious because there could be heat loss from the pipework.
Ideally the temps should be measured inside the machine.

Energysaver

CJhaughey wrote: »

When you measured the exhaust and intake temps did you do this inside the house or at the wall vent/intake on the outside of the house?
I am just curious because there could be heat loss from the pipework.
Ideally the temps should be measured inside the machine.

I put the temp probe into the ceiling vents in each room. I agree that I should have ideally taken the temp from the inlet and exhaust ports of the hrv unit itself but that would have involved a lot more effort on my part.:o

exhaust duct to hrv distance from kitchen isn't far so I wouldn't anticipate much heat loss, but sitting room to hrv is a bit further (but obviously I can't quantify heat gain/loss in ducting).

Cookie_Monster

probe wrote: »

If I was having a new house built in Ireland, I'd probably buy a www.huf-haus.com in Germany and have them bring it over and install it on site.

Slightly OT but Grand Designs did a programme with one of these houses, they're brilliant and it's a pity you don't see to many of them over here.