Ventilation in old house

H

Honeydew

Registered User
Messages
5
I have two awkward rooms in an old house which have no vents. Can anyone assist with whether my suggestions will suffice?

Room 1: very little external wall space, but has a chimney we will be closing up. Can we put a vent in the plaster/ insulation in the flue and use this as a nice hidden vent with no gusty wind?
Room 2: has plenty of external wall, but will window vents suffice as the house is cold?

Thank you
 
You have given precious little information to work with so take the following comments with a healthy pinch of salt.

You don't say what issue you are trying to solve so whether what you have suggested will suffice or not is anyone's guess.
Some houses without vents are fine and others have problems such as condensation, mould and cold. Similarly, some houses with vents are fine and others have problems. Looking at vents and ventilation requirements in isolation without taking into account other aspects of the house and household is not the best way to proceed, imo.
And then you have the building regs which specify the minimum standards for domestic ventilation.

Room 1 - the technical term for a chimney is a 'passive stack ventilator' so by closing it up you are, in fact, removing ventilation (notwithstanding the new vent)!
Room 2 - it may or it may not ... why is the house cold I wonder ... maybe this is where you should start because if the house is cold then whatever ventilation there is, it won't be efficient at doing it no.1 job and that is getting rid of moisture.
 
Thank you, sorry about the lack of information.
My basic first thing to solve was what are the basic necessary requirements to be fulfilled. I've had a look at the regs, different parts, years, it is hard to see what is required now at minimum in a non new build. I guess I am asking if window vents suffice and I don't have to knock holes in walls?

We are tackling the cold issue by insulating floors, walls, changing windows, all the basics. The wall pump people said we would have to have wall vents in two rooms before the pump. After making the house warmer, if possible I don't want to then add wall vents. So, if I can vent into a well insulated chimney with some air flow and window vents, or just have window vents in both rooms it would be great.
 
Trickle window / 'hole in wall' vents and intermittent extraction in kitchen and bathrooms are, in my opinion and experience, generally not suitable in our climate for various reasons notwithstanding the fact that it is still to be found in the building regs and would be allowed as the basic level of ventilation in homes.
My advice would be to look at least at the next level up such as something like a whole house mechanical system such as cMEV (centralised mechanical extract ventilation).
 
Honeydew said:
Thanks Mick. Apparently the walls cant be pumped without the vents?
Click to expand...
I’d guess wall vents are required if you are availing of the grant; if you were paying cash I’m sure you’d find someone to pump walls without making the holes

seai registered installer would risk their work being audited and vents are required under regs {at least that’s what I’ve been told)
 
Micks'r said:
Trickle window / 'hole in wall' vents and intermittent extraction in kitchen and bathrooms are, in my opinion and experience, generally not suitable in our climate for various reasons notwithstanding the fact that it is still to be found in the building regs and would be allowed as the basic level of ventilation in homes.
My advice would be to look at least at the next level up such as something like a whole house mechanical system such as cMEV (centralised mechanical extract ventilation).
Click to expand...
Need a good level of air tightness for it to work properly; might be hard to achieve in an old house, I’d get an airtight test done before spending money on a ducted ventilation system; plus fitting in an refurb can be very difficult (costly and disruptive)
 
Honeydew said:
Thanks Mick. Apparently the walls cant be pumped without the vents?
Click to expand...
Not totally correct I believe. The requirement I understand is appropriate ventilation. 'Hole in wall' vents are the most basic method of ventilation but there are much better ways of ventilating.
 
Last edited:
Cameo said:
Need a good level of air tightness for it to work properly; might be hard to achieve in an old house, I’d get an airtight test done before spending money on a ducted ventilation system; plus fitting in an refurb can be very difficult (costly and disruptive)
Click to expand...
For cMEV, good airtightness, while a nice to have, isn't essential for effective / efficient ventilation and can be quite easily retrofitted in most houses.
For other types, such as DCV or MVHR, you are correct that good airtightness is important.
 
Honeydew said:
Thank you, sorry about the lack of information.
My basic first thing to solve was what are the basic necessary requirements to be fulfilled. I've had a look at the regs, different parts, years, it is hard to see what is required now at minimum in a non new build. I guess I am asking if window vents suffice and I don't have to knock holes in walls?

We are tackling the cold issue by insulating floors, walls, changing windows, all the basics. The wall pump people said we would have to have wall vents in two rooms before the pump. After making the house warmer, if possible I don't want to then add wall vents. So, if I can vent into a well insulated chimney with some air flow and window vents, or just have window vents in both rooms it would be great.
Click to expand...
One of the reasons I discovered previous residents in my house had blocked off all the vents on one side was because when I heated the rooms, there was no air circulation and the room wasn't heating up. If you don't have ventilation in the room whatever heating you have won't circulate around the room. Once I cleared all the debris, newspaper, polystyrene etc out of the vents even modest heating actually spread around the rooms in question. You'll also have issues with damp if there is no ventilation, if there isn't already.

Of course, if you are installing an internal ventilation system or air conditioning this might not matter but it will if the house becomes air tight.
 
lff12 said:
If you don't have ventilation in the room whatever heating you have won't circulate around the room.
Click to expand...
You should still get heat distribution in a closed room. Radiators are designed to warm the air in contact with them, this rises upwards above the cooler air pulling in cold air from below creating a circulation within the room. Halting that heat circulation would require a vacuum.
 
Honeydew said:
I have two awkward rooms in an old house which have no vents. Can anyone assist with whether my suggestions will suffice?

Room 1: very little external wall space, but has a chimney we will be closing up. Can we put a vent in the plaster/ insulation in the flue and use this as a nice hidden vent with no gusty wind?
Room 2: has plenty of external wall, but will window vents suffice as the house is cold?

Thank you
Click to expand...

Ventilation is a complex topic and depends on many local factors like house exposure and household size and other factors. Irish law prescribes vents in every room as a precautionary principal but in many cases they are absolutely more harm than good, for example a house that was occupied by empty nesters or a house where there is no daily showers, cooking or baths. Mechanical systems are ideal. Get a cheap humidity sensor (15 eur) and measure the temperature and relative humidity for a few days and record it and report back here.
 
You must log in or register to reply here.
Back
Top