Ventilation demand control pic or extraction

homewardbound11

Hi ,
A family member is extending their 1997 home . So the house won't be airtight or wind tight . They are also extending into the attic .
So with that they are on an exposed site to wind .
The currently have the hole in the wall ventilation .

Question .
What is the cheapest best option to control the airflow in this house as they are loosing a considerable amount of heat by airflow in the house .

Also as they will be extending into the attic . What is the best way to make the upstairs wind tight . I fear there will be considerable losses here also if not detailed .
I am deliberately avoiding air tightness as this would just involve retrofitting the entire house which is not possible for them .

Please pm any recommendations as they will be starting in the next 4 weeks .

Calahonda52

The title says Ventilation demand control pic or extraction
you then say So the house won't be airtight or wind tight. why not?

What do you understand by wind tight, airtight?

You then say
I am deliberately avoiding air tightness as this would just involve retrofitting the entire house which is not possible for them .
What basis do you say that?

You need to clarify your thinking here and perhaps stop using catchy words and expressions that clearly you have read but perhaps don't understand

Have a read of this https://www.nsai.ie/S-R-54-2014-Code-of-Practice.aspx

homewardbound11

Yes,
That's correct .
Retrofitting for air tightness is not possible for this case due to circumstances .
I am well familiar with Mhrv and air tightness. I did it as part of my self build 5 years ago.
In this case I do not require heat recovery as the house will not be airtight.
It is purely a case of controlled ventilation due to the exposed conditions they live in. The wind in the hole in the wall conditions can simply strip the house of its heat .
I hope you understand it now .
Hopefully someone can answer if this option is practical in this situation.

Dardania

you could sue demand controlled ventilation e.g. - Snip- The one I have has little excess wind dampers built in -snip-

homewardbound11

Calahonda52 wrote: »

The title says Ventilation demand control pic or extraction
you then say So the house won't be airtight or wind tight. why not?

What do you understand by wind tight, airtight?

You then say
I am deliberately avoiding air tightness as this would just involve retrofitting the entire house which is not possible for them .
What basis do you say that?

You need to clarify your thinking here and perhaps stop using catchy words and expressions that clearly you have read but perhaps don't understand

Have a read of this https://www.nsai.ie/S-R-54-2014-Code-of-Practice.aspx

If you read back your answer you hopefully will start to appreciate your patronising tone to your answer . Hopefully your are not like that normally .
I can tell you that retrofitting is not possible for air tightness for family personal reasons. I cant explain any further.

MicktheMan

homewardbound11 wrote: »

Hi ,
A family member is extending their 1997 home . So the house won't be airtight or wind tight . They are also extending into the attic .
So with that they are on an exposed site to wind .
The currently have the hole in the wall ventilation .

Question .
What is the cheapest best option to control the airflow in this house as they are loosing a considerable amount of heat by airflow in the house .

Also as they will be extending into the attic . What is the best way to make the upstairs wind tight . I fear there will be considerable losses here also if not detailed .
I am deliberately avoiding air tightness as this would just involve retrofitting the entire house which is not possible for them .

Please pm any recommendations as they will be starting in the next 4 weeks .

homewardbound11 wrote: »

Yes,
That's correct .
Retrofitting for air tightness is not possible for this case due to circumstances .
I am well familiar with Mhrv and air tightness. I did it as part of my self build 5 years ago.
In this case I do not require heat recovery as the house will not be airtight.
It is purely a case of controlled ventilation due to the exposed conditions they live in. The wind in the hole in the wall conditions can simply strip the house of its heat .
I hope you understand it now .
Hopefully someone can answer if this option is practical in this situation.

This makes no sense.
One the one hand you are saying that you want to reduce the already severe convection heat loss by air infiltration caused by a lack of air tightness and on the other hand you are ruling out any air tightness improvements. And all this on an exposed site!

homewardbound11

Mick
,
If you had hole in the wall ventilation and wanted to control the flow through it it would u use dcv . Really I would like to see posts from users of it .
That is what I am saying . Or are you saying that all ventilation control is pointless without air tightness.,
For Mhrv it used to be <2@q50 if I remember. I am asking the question with dcv and anyone with results for houses that were not airtight tested to levels where Mhrv requires as in this case .In my case the house wS not airtight tested at all .

For me it is clear the hole in the wall allows excessive ventilation so much that you can feel the cooler air flow stream on a winters night . 2 holes in a box and positive pressure will blow in one hole and out the other and also if leaks are present . If I can control both holes then surely the results would be less air flow and heat loss.
If controlled ventilation could be used . Surely that would be a bonus .



I will see what aereco can come back with as it is just black and white from what it seeing here .

BryanF

Sorry can't help you, I've specified DCV in retrofits in the best case we achieved enerfit levels of air-tightness (~1ACH) in the worst we didn't test but still taped typical junctions and detailed for air-tightness.

homewardbound11

BryanF wrote: »

Sorry can't help you, I've specified DCV in retrofits in the best case we achieved enerfit levels of air-tightness (~1ACH) in the worst we didn't test but still taped typical junctions and detailed for air-tightness.

Thanks, I was kind of hoping you'd drop a line with some answer other than the above .
That's the info I'm looking for .
Take a house with air tightness as in my own case we achieved 1.2
Take it 5 years later and with the odd composite door starting to loose tightness with the frame . Take the 3 glazed windows dealings .
I'm guessing that my airtight ness now compared to install would be a lot less.

So it brings me back to the current situation . Of what I have learned then probably and air tightness test and smoke test would be no harm to get a base level Before deciding on dcv


For you information . The suggested supplier for dcv on cork have said there is minimum airtightness requirement for dcv . Obviously the lower the better .