Scottish parliament Committee 'expert' opinion

[Alex C]

I went to an conference by the Good Homes Alliance a few years ago that was addressing air quality in buildings. The meeting was attended by large landlords and house builders such as the Peabody trust. It was very evident that at the time a lot of the well insulated homes with mvhr being built were by some of these organisations that are renting to a particular demographic. The Peabody trust said there was a real issue with their new flats being overpopulated, full of wet washing and mvhr turned off with no heating on either as tenants thought it was too expensive to run. I am pretty sure this then skews statistics for air air quality in new builds due to the numbers being built, versus well informed self builders. As has already been mentioned, some people are just not able to function in a home in the way well insulated and airtight houses need to be.

[Ferdinand]

PErhaps a letter to Ms Roaf herself requesting her evidence base and participation in this thread would not go amiss.

[Crofter]

@jamiehamy

Good points but might I suggest you consider making it primarily focused on the issues rather than the person? Just might find a better reception that way, IMHO.

 

Oh also wee typo there- "quiet literally".

 

(Right I'll switch off my school teacher mode again now!)

[Crofter]

On the topic of user-friendliness, I remember years ago when my granny had storage heaters installed, my parents were unable to persuade her that turning them on and off at the wall would not affect the temperature of the room immediately. But she was used to plug in 2-bar fires and could not understand how these newfangled things could be any different.

 

My current day version of this is our slightly more sophisticated storage heaters, which have baffles to keep the heat in. I have tried to explain to SWMBO that if we default to keeping the baffles closed, then it will not make the room any colder because the heat will still escape, just a bit slower, plus you will be able to open them for a boost when you need it. However she insists on running them with the baffles open so when we have a cold snap all we can do is turn up the input and wait 24hrs to enjoy the benefit.

 

On MVHR, I am specifying it partly because I want improved air quality. My previous house (standard construction 80s bungalow) had some big problems with mould and damp behind the furniture in the spare bedroom etc. I am assuming that an active ventilation system is going to help me avoid these problems. However I don't plan on letting the occupants even know that the system is there, let alone having control over it (this being for weekly lets rather than long term letting).

[Ferdinand]

1 hour ago, Sensus said:

 

It's probably fair to say that, purely in terms of air quality, you can't improve on high levels of natural ventilation (assuming the external atmosphere isn't so polluted that you need to filter particulates out). Humans evolved outdoors, and work best with a constant and unrestricted supply of fresh air: air that has been nicely stirred up by the weather to dilute contaminants and pathogens, and freshly oxygenated by plants.

 

Where MVHR scores is that, when it is properly designed, installed and maintained, it offers a much better balance of air quality:energy efficiency than any natural ventilation strategy, when there is a lot of emphasis on the energy efficiency part of the equation.  But you've got to live with the fact that it's always forced (for a variety of technical reasons I won't bore you with) to operate at the lower end of what's 'good' for a human being in terms of ACH/hr, so if it is not properly designed, installed and maintained, it's easy to tip that compromise too far in the wrong direction.

 

 

 

But .. the point that the Parliament session ignore .. The answer to wrong use is right use not disuse. EVen if that includes user education or control system simplification.

 

Agter all, we all use gas boilers without being gas boiler technicians.

 

Ferdinand

 

Edited September 24, 2016 by Ferdinand

[ProDave]

Re mvhr and operating at the lower levels acceptable for humans.

 

The flow rates are dictated by building regs based on occupancy and size.  Our new house, with 3 bedroms, is deemed by building control to accommodate 5 people.  The reality is there will be 3 of us living there. So we will have a house with an air supply capable of supporting 5, with only 3 of us using it. I think that will do.

 

I suspect very few self built detached houses come anywhere close to their maximum occupancy.  Our present 5 bedroom house is sized for 8 people but rarely has more than 7 (when both b&b rooms are occupied) and very often just the 3 of us.

 

Where this may be an issue is at the other end of the spectrum ins small 3 bed terrace houses in town where you will much more likely find all rooms filled to (and beyond) capacity.