@derek-m what amount of ventilation do you suggest please ? I have downloaded the 62 page Building regs part F Ventilation Vol 1: Dwellings, but can't stay awake reading it !

Posted by: @heat-pump-newbie

@derek-m what amount of ventilation do you suggest please ? I have downloaded the 62 page Building regs part F Ventilation Vol 1: Dwellings, but can't stay awake reading it !

Hi Newbie,

I'm surprised that such an interesting read would send you to sleep.

I suppose that it very much depends upon how 'leaky' your home happens to be. You could buy a canary, and when it falls off its perch then you should open a window. 😊 Alternative you could get a Carbon Dioxide detector and do the same when the alarm goes off.

From the ventilation point of view we don't really have to worry, since we have a chimney and a cat flap. so there is a reasonable amount of ventilation. In the bathroom we have an extractor fan with a humidity sensor, so it automatically switches off when it has cleared the condensation. Since this particular concept of ventilation requirements was first posted I have been giving it some thought. First of all is it necessary to ventilate unoccupied rooms? Do you need constant ventilation or just when the CO2 level has increased?

It may be possible to arrange a ventilation system that only runs when the CO2 levels increases and then shuts off when the level is back to normal.

My primary concern is that I have to sort out the ventilation before ordering the new windows, or they'll have to put trickle vents in them, according to the new regs that come in on the 15th June 2022 (page 2 of regs so still awake for that).

I also have a fireplace, using a wool 'chimneysheep' pad to block draughts without compromising ventilation of the chimney. That, I'm sure, would not suit MVHR. 

I like the idea of a CO2 controlled ventilation system. Do they exist or have you just invented the idea ?! (no pun intended)

Posted by: @heat-pump-newbie

My primary concern is that I have to sort out the ventilation before ordering the new windows, or they'll have to put trickle vents in them, according to the new regs that come in on the 15th June 2022 (page 2 of regs so still awake for that).

I also have a fireplace, using a wool 'chimneysheep' pad to block draughts without compromising ventilation of the chimney. That, I'm sure, would not suit MVHR. 

I like the idea of a CO2 controlled ventilation system. Do they exist or have you just invented the idea ?! (no pun intended)

If you Google Carbon Dioxide Detector there are quite a few available, and most if not all generate an alarm. I have not found one yet, but there may be some which have an alarm contact that can be used to stop and start an extraction fan.

Posted by: @derek-m

Posted by: @heat-pump-newbie

My primary concern is that I have to sort out the ventilation before ordering the new windows, or they'll have to put trickle vents in them, according to the new regs that come in on the 15th June 2022 (page 2 of regs so still awake for that).

I also have a fireplace, using a wool 'chimneysheep' pad to block draughts without compromising ventilation of the chimney. That, I'm sure, would not suit MVHR. 

I like the idea of a CO2 controlled ventilation system. Do they exist or have you just invented the idea ?! (no pun intended)

If you Google Carbon Dioxide Detector there are quite a few available, and most if not all generate an alarm. I have not found one yet, but there may be some which have an alarm contact that can be used to stop and start an extraction fan.

There are some that work with Samsung Smart Things which could be used to trigger other appliances with appropriate switches.

Also a lot of similar zigbee co2 sensors that can be used to trigger other appliances with a home automation setup. 

Search zigbee co2. I don't know which are any good so i haven't posted a link. Somewhat depends on what you want to do generally with home automation and also which way the industry goes. Not an area i know much about. 

@jeff Thanks - I think that might be over my head - I looked at home automation and zigbee stuff a while ago and it looked like a major learning project for me. 

Really I'd just like to know what constitutes adequate ventilation so that I don't have to have trickle vents, they'd be and extra cost per window and let heat out. Sounds like 'Lose-Lose'.

@jeff @derek-m

Do you think a PIV system would be enough to satisfy the legal ventilation requirement ? I can see how I could set that up in my bungalow - I'm looking at the https://www.vent-axia.com/range/lo-carbon-pozidry-compact-pro

Although I have a loft I could install this in a cupboard where the old gas heating was, so have a fresh air input already, also the flue for output ?

@heat-pump-newbie

I'm afraid that I don't know. What are the legal ventilation requirements?

Posted by: @heat-pump-newbie

@jeff @derek-m

Do you think a PIV system would be enough to satisfy the legal ventilation requirement ? I can see how I could set that up in my bungalow - I'm looking at the https://www.vent-axia.com/range/lo-carbon-pozidry-compact-pro

Although I have a loft I could install this in a cupboard where the old gas heating was, so have a fresh air input already, also the flue for output ?

My understanding... 

Unfortunately the PIV system doesn't meet the building regs as an alternative to trickle vents. The PIV also doesn't meet the building regs for extraction for kitchens, bathrooms etc. as an aside. The PIV systems rely on the fact buildings are not air tight. 

So you will need either a compliant mechanical ventilation system or trickle vents post June. The mechanical systems will mention if they are compliant, but you might need to double check with manufacturers given the change in the regs. 

Of course if you don't have trickle vents now and you get the replacement windows in before June then you don't need trickle vents as per the old regs. It all changes in June. 

@jeff Oh blast ! Thanks Jeff. The updated windows won't be going in before September so it'll have to be a compliant ventilation system. Is there a system for not-too-leaky buildings somewhere between MVHR and PIV ?! or should I be only looking at MVHR ?

Posted by: @heat-pump-newbie

@jeff Oh blast ! Thanks Jeff. The updated windows won't be going in before September so it'll have to be a compliant ventilation system. Is there a system for not-too-leaky buildings somewhere between MVHR and PIV ?! or should I be only looking at MVHR ?

My understanding.... 

Window companies sign off their installation is compliant with building regs so i would start by asking them what they would need to see installed in your home to not fit trickle vents to the windows. They may have already done this for installations prior to the upcoming rule change. 

I suspect unofficially this varies between suppliers about what they are happy to do... 

I suspect you will have to compromise somewhere between trickle vents vs mechanical ventilation without heat recovery vs mechanical ventilation with heat recovery.

Perhaps drop an email to one of the manufacturers to ask about which of their products are compliant. Could start with vent axia for example.

https://www.vent-axia.com/contact

@alec-morrow i would have thought might have some thoughts. I doubt his single MVHR unit solution would be compliant in your home with new windows and the new regs. He may have some ideas about the best compromise products/solutions given the new regs around trickle vents.