Some Basic home ventilation

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Stephendnz

51 posts

Master Geek

#248888 14-Apr-2019 23:38

Wondering if i could get some advice please on a plan I have for some basic ventilation for our old house we have owned a couple of years and almost finished doing up...

Some background.. Old house.. 70 + years.. 2.8mtr ceilings.. 120 m2..

So far we have:

1. Laid polythene liner on ground under floors.. to stop the dampness..

2 Installed Polystyrene insulation between joists..

3.Put a tonne of Batts in the ceiling. 150mm +

4. Have so far double glazed all the south side windows.. DIY using plexiglass.

All together this makes the house pretty warm but unfortunately our plans have changed somewhat and we might not be here as long as we planned initially.. so we don't want to spend too much money on it.. for ventilation..

While we leave windows and doors open a lot for ventilation.. I was wondering if pumping some fresh air into the house with would help to reduce dust and I guess must help generally to reduce dampness..

I have a Weiss inline fan (I think from a room-to-room heat transfer system) that runs at 362m3/hr / 100.6l/sec that I was planning to use to bring fresh air in from under the eaves..

Question 1: I guess I would bring this in from the north side of the house.. how much do you think I could achieve by doing this.. the lounge/dining/kitchen is an open plan design.

We also have a sunroom on the north side that heats up like an oven during the day.. even in the winter.. and I was planning to use a through-wall fan to bring that heat into the adjoining lounge, which while it is also north facing, the eaves don't allow as much sun into the lounge..

Any thoughts would be appreciated..

timmmay

20578 posts

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#2217154 15-Apr-2019 07:26

I have a similar house to you, and have done similar things to you, though I've gone a bit further. I have a small ventilation system which takes air from the eaves rather than the original location of taking it from the dirty, smelly roof cavity. I recently upgraded the fan to a much more powerful model and added a filter in a filter box, G4 I think it is, which is rated to catch dust, pollen, etc, but not the smallest particles.

Pushing fresh air in from the eaves definitely makes the house fresher. Upgrading to a fan with a high capacity (currently approx 400 cubic meters per hour) helped more. I don't think it's helped with dust, because there is still dust in the carpet, on the walls, etc, even though it's vaccumed regularly, cleaners dust, etc. We're getting the carpets cleaned in a week or so, which I hope reduces dust a bit.

I took air from the south side, just because it's away from a neighbour that has a fireplace. The filter has helped reduce that smell though.

Bringing air from the sunroom might be good in winter, but as well as a fan you need an opening to allow air into the sunroom otherwise you're creating a vacuum.

Stephendnz

51 posts

Master Geek

#2217272 15-Apr-2019 10:38

Thanks Timmmay, Thanks for your feedback..

Yes I had planned to bring the air in from the eaves as opposed to the roof space.. and had thought about the southside as an option for the same reason, and also with the installation of a filter... we must have the same annoying neighbour.. accept here they also burn coal.. sticks like you know what..

I was even wondering what if I directed the air from the outside (under eave) into the actual roof space for a few weeks or longer.. would this have the effect of pushing out the dirty air.. (dust smells etc.) plenty of air gaps up there to get outside I think.. and then maybe in the winter use some of that hot air up to bring into the house.. and trust me it gets VERY hot up there..

When you say you "recently upgraded the fan to a much more powerful model".. do you mean yours is now 400m3 hr or was before.. because mine is close to that.. 362m3/hr.

Regarding the dust. we have removed most of the carpets and now have nice wooden floors that with the installation of the underfloor polystyrene are actually almost warm to walk on.. and most of the dust is just from the road,, and the river behind us - when the water level drops down a lot..

"Bringing air from the sunroom might be good in winter, but as well as a fan you need an opening to allow air into the sunroom otherwise you're creating a vacuum."

Thanks.. yes it would be easy enough to have a a window ajar for this reason..

Thanks again for your help..

Stephendnz

51 posts

Master Geek

#2217276 15-Apr-2019 10:46

EXTRA INFO..

I do already have a power source in the ceiling that is controllable from the lounge.. a light wiring we decided not to use for the light.. and so its easy to just switch fan on and off as we need.. i guess in the warmest part of the day.. in the winter.. :-)

Was thinking would try and clean the air in the roof space by blowing fresh air in there via the eaves for a few weeks or longer.. then using the roof space heat in the winter months..

Mostly have wooden floors..

Heating source.. Long story and won't bore you with the reasons as to why.. but now just just oil heaters in bedrooms before bedtime.. and a portable gas heater during the cold mornings..

Live in the Sth Island.. some mornings start off at 0 degrees.. brr..

timmmay

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#2217358 15-Apr-2019 12:51

I found that in winter the roof space is warmer than the house, but not enough to be all that worthwhile given the poor air quality. Roof space air changes fairly frequently so I see no point pushing air up there. The problem tends to be old insulation, old materials, often things like rat / mouse droppings, smoke from neighbors.

My new ventilation system does 400 cubic meters per hour. In winter I have it on something like 9am to 3pm, and then for a short time after dinner and in the middle of the night to push a bit of air through. We don't need it on all the time, that just pushes cold air through. In summer I have it on more like 6am to 10am and 5pm to 11pm. We heat / cool using two air pumps.

If I had a house I was staying in long term I'd get an integrated ducted ventilation system that had a big heat pump with it.

Stephendnz

51 posts

Master Geek

#2217626 15-Apr-2019 20:10

Thanks for the feedback..

Kickinbac

427 posts

Ultimate Geek

#2217629 15-Apr-2019 20:14

Stephendnz:
EXTRA INFO..

I do already have a power source in the ceiling that is controllable from the lounge.. a light wiring we decided not to use for the light.. and so its easy to just switch fan on and off as we need.. i guess in the warmest part of the day.. in the winter.. :-)

Was thinking would try and clean the air in the roof space by blowing fresh air in there via the eaves for a few weeks or longer.. then using the roof space heat in the winter months..

Mostly have wooden floors..

Heating source.. Long story and won't bore you with the reasons as to why.. but now just just oil heaters in bedrooms before bedtime.. and a portable gas heater during the cold mornings..

Live in the Sth Island.. some mornings start off at 0 degrees.. brr..

If anything, please get rid of the gas heater ASAP. They should be banned as they add moisture to your house, carbon monoxide and are inefficient. A radiant electric heater would be better.

pctek

807 posts

Ultimate Geek
Inactive user

#2220974 19-Apr-2019 09:51

Remove the fire hazard polystyrene.

Hot air rises, not cool air.

Open a window, doesn't have to be much.

Sealing your house up like a plastic bag is the issue.

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Stephendnz

51 posts

Master Geek

#2221300 19-Apr-2019 22:01

Thanks K.. Yes I know I should get rid of the gas heater.. but I do like the flame.. and never really smells too bad.. usually a window open somewhere even in winter.. so hope wont get asphyxiated..

Ptech.. thanks for your feedback.. but not really sure what all that means to be honest..

(Remove the fire hazard polystyrene.) I did try to burn that stuff before I bought it.. and wouldn't burn well only if you hols a flame on it.. but wont actually ignite.. and its been great under the floors.. very warm to the feet.. even in winter..

(Hot air rises, not cool air.) Yep aware of this but now sure what you are referring to.

(Open a window, doesn't have to be much.) Yep .. do that every day.. mostly doors and windows all open... but was really trying to deal to the dust as much as anything.. I thought the effect of blowing filtered air into the house was good for this. am I wrong??