Thanks @PhilT, an interesting request. I don’t think air quality measuring instruments are an item of major interest for many consumers - I expect most people who are concerned about the air quality in their homes simply buy an air purifier and rely on its relatively basic air quality display. But now that we have a test method for air purifiers, perhaps we could include some monitors and assess them in the same test facility. Not sure if we could do CO2 or CO, but particulate matter, temperature, humidity and perhaps some other aspects could be measured. I’ll keep it in mind for next time we’re looking at air purifiers. But note that we are very careful with our testing budget - there’d have to be a convincing consumer need for us to do this particular test.
Hi Chris,
Thank you for considering my request.
I think it’s important to note that CO2 monitors are quite different from air purifiers however given the recent (and overdue) acknowledgement that COVID is airborne, there will obviously be a need for more information relating to air filters particularly HEPA filters etc for use where windows, doors can’t be opened to enable ventilation and how air quality within enclosed spaces can be monitored with a CO2 monitor.
Given this will be a new and expanding consumer market in addition to business, corporate and industrial sectors, it would be really helpful to know what products perform as they claim etc. At present there are many products available ‘on line’ (and growing) but quality, reliability, accuracy etc is an unknown.
In the meantime, if anyone has any recommendations I’d be most grateful and of course, wear a mask as required, and please get vaccinated.
Cheers
Really?
It’s great to point out mask use and vaccination will reduce the risks from Covid-19. In an environment free of Covid ventilation quality is irrelevant. In a Covid rich environment such as a quarantine environment or hospital isolation ward? Ventilation management is an obvious need.
Note:
A high CO2 level does not equate to a high Covid 19 viral load. Conversely, a high Covid viral load is not necessarily due to a high CO2 level. A high CO2 level is simply an indication that ventilation may be less than optimal. Covid or no Covid.
If we treat the cause, through vaccination, why waste resources on a falsehood promoted by the ventilation industry for it’s own outcomes?
Covid is often spread through close contact or proximity in the home where CO2 levels are not elevated. A common source of community transmission.
It seems a weak argument that CO2 monitoring is essential to everyday prevention, nor is it a reliable tool for measuring viral loads. There are many reasons for high CO2 levels in a room or space, none of which are due to Covid-19.
P.S. (edit)
It is understandable some of us see increased CO2 as a reason to be alarmed. Unfortunately a normal CO2 level in most indoor environments does not assure one cannot become infected.
Two out of three of your requirements. It would be best to look to professional grade equipment. It will come with certified calibration and reliable support for retesting or recalibration as needed.
https://www.draeger.com/en_aunz/Substances/254
Whether Choice could reliably assess a non professional grade product, suitable for use in a workplace? The result for a sample of one, might not provide any assurance a product subsequently purchased from the same brand would perform as well or better. To assess reliability and calibration/accuracy over time would the testing require use over many months?
One cheaper product appears to have quite a poor accuracy +/-50ppm plus 5% of the reading. It’s quite a significant variance compared to average background environmental levels of CO2 at 420ppm.
Calibration can be a very expensive procedure. Certification adds the cost of a NATA registered lab.
Hi @Annie99, I agree that interest home air quality monitoring is likely to grow quickly, due to the focus on ventilation (and CO2 levels as the proxy measurement) for COVID control, smoke from bushfires infiltrating homes and also with higher home energy efficiency standards meaning new homes are much more airtight and thus at risk of high CO2/low O2 without appropriate (but controlled) ventilation.
I’m looking to get a home CO2 monitor so I know when I need to open windows to refresh air in the house, while balancing not having them open more than necessary so I’m not losing heat (winter) or cool air (summer) unnecessarily. So I need continual monitoring, not a once off test performed by experts in a lab. And I don’t need a super high level of accuracy, but good enough. Ideally I’d also like to monitor interior humidity levels as well as this has a big influence on comfort and health. My air purifier will tell me PM2.5, VOC and IAI, but not CO2 (or CO) or humidity. There are quite a few home air quality sensors out there, but I have no way of knowing which are the better ones. @ChrisBarnes, it would be great if Choice reviewed them.
Welcome to the Community @Bongobec.
Is CO2 really a proxy?
The following suggests it is not an assured outcome.
Note also:
The safe exposure levels for CO2 per OSHA 5,000ppm (PEL 8hrs) are many times greater than typical measured indoor and environmental levels, (around 412ppm at Cape Grim).
Good ventilation of a home is important for many reasons. Our strategy with Covid is to ensure everyone that can be is vaccinated.
I think there are many strategies that are more useful for managing the risk of viral transmission in the home than monitoring the amount of CO2 you are sharing with others in the same house. There are simpler ways to work out if you need to air your house too.
In uncertain times people seek reassurance. Why not get a gadget for it, you can get one for everything else?
In a household setting measuring CO2 content seems a waste of time and money in the context of a useful way of avoiding COVID. Better off ensuring that household members are either vaccinated or get tested any time symptoms appear in household members.
Of course if you are having large numbers of visitors without wearing masks, washing hands and maintaining personal distancing then like a commercial property it may have benefits. Otherwise it seems overkill to me and having no real benefit for a household.
The ABC has offered a potpourri of information. It’s not consistently offering the same advice.
Note:
Professor Siegel also argues it’s important to measure CO2 levels over time, and to understand that different parts of the room will give different measurements.
“CO2 monitoring is fine if it’s done well,” he says.
Otherwise, he says money is better spent on improving ventilation and air filtration.
From the ABC it’s not evident at which point a CO2 monitor adds benefit in a home environment when it comes to reducing Covid risk. As a security blanket, it has a potential to be causing undue anxiety where it suggests home owners are at risk, when there is no significant issue to resolve. The worse outcome may be to become overly reliant on a cheap CO2 monitor.
Especially when all one needs to do is open the windows and follow Covid Safe practices.
What are the simpler ways @syncretic ? From what I’ve seen in energy efficient home sites, CO2 is the main way people are measuring whether the house is adequately ventilated. Yes I could keep my windows open all the time, but then what’s the point of building an energy efficient home with good sealing of the building envelope? Our house isn’t at the level where we need an HVAC system, but is I suspect at the point we should be keeping an eye on CO2 levels to make sure we are ventilating often enough. I agreed that measuring CO2 in a home environment as a way of monitoring for COVID transmission risk would be pointless in most situations (exceot possibly when hosting larger parties?), but I can set it being beneficial for other reasons.
The background is a newish concrete/steel/hardiplank/colourbond house. Sun-oriented, well sun protected, pale colours, roof blanket, insulated in walls and roof, double glazed, ducted reverse cycle aircon. It is energy efficient and well sealed with sliding metal framed windows and doors.
My process is as follows.
-
Has the house been ventilated today: if no consider opening up.
-
Does it smell stale, are people feeling dull: if yes consider opening up.
-
Will there be a better time to open in the next 12-24 hours: if yes do it then unless necessary now.
-
Is pollution outside thick now: wait.
-
Is the temperature and pollution OK: if yes do it now.
etc etc
I do not find this decision hard to make and I don’t waste energy with the aircon on and the house open, or allowing the house to reach uncomfortable ambient temperature before using the aircon to make it comfortable. All it takes is some observation and thought.
For example:
- Midwinter: If the temperature gets reasonable later in the day open up and turn off air for an hour, typically while I go out for exercise.
- Midsummer; wait until outside is cool, this could be midnight or 6am, before opening up, close again before the day gets too hot, usually about 9am. The house will be open much longer than required for air circulation, the aim is to also cool the slab and the building, this will keep the house cool for several hours even if the outside temperature jumps up quickly after closing.
- Between seasons; leave the house open and the aircon off as much as possible.
This is not rocket science, I don’t need a gadget to tell me the house is stale. I don’t know where CO2 gauges are de rigueur I am fairly sure I don’t know anybody who owns one.
@syncretic, I’m not convinced that we can always judge “stale” air effectively enough to know when to open up, plus they’re are large parts of Australia where the winter days don’t get warm enough to open up the house for an hour without losing a lot of the warmth inside, plus I’m not always home during the warmest part of the day (and conversely in warmer parts of the country nights can remain uncomfortably warm, so opening up overnight is not always beneficial). And sometime ventilation is needed more than once a day, especially if shutting off individual rooms. There was an article in the most recent edition of Renew Magazine by an architect in Sydney who found that his young daughter’s bedroom was regularly exceeding 1500ppm CO2 every night, and getting close to 2,500ppm at times with the window and door closed. With bedrooms it’s not always practical to keep doors open.
People seem to have managed for thousands of years. There must be some very bad consequence of getting this wrong in the back of your mind.
There are days when fresh air and maintaining inside temperature clash. A CO2 monitor will not solve those problems. I am not claiming to control the weather just being able to do the best to deal with it (or close to it) without a machine measurement of CO2.
Yes, I still don’t need to carry a machine around to know that.
What harm do you think the child might suffer and how would having a CO2 monitor prevent it if the doors and windows must remain shut?
I know people who don’t have aircon and once away from the fuel stove the rooms get very cold on winter nights. Their children get a concession to only have the bedroom window open a bit those nights. They have thick doonas.
Another problem exists and that is where the CO2 measurement is being taken. As CO2 is heavy it pools lower down, so where do you place a device to adequately measure in a room. If at floor level then results could be quite skewed towards higher readings, at the ceiling then it could be skewed to lower readings, perhaps head height but in a household with smaller children then this may be leaving them in higher concentrations than the adults.
I think in a bedroom leaving a window slightly ajar and having warm quilts/doonas/blankets is going to a better answer than taking multiple readings a night to determine when to open and shut to allow exchange (and to ensure adequate exchange would mean large amounts of ventilation to ensure pooling was eliminated). If concern is that great then a system that heats the outside air and pumps it into rooms is going to be the best answer in the cold. If extremely hot inside then a system that cools outside air and pumps it into rooms is also an answer. Both of these are expensive energy wise as there is generally very little recirculating air unless you are using a system as pointed out by @mark_m in their reply below.
If concerned that a particular room such as a child’s bedroom is getting high readings because the door and windows need to be closed then fitting a vent in the bottom of the bedroom door to allow air to move out of the room and to circulate with the remainder of the house should ease those concerns, particularly as CO2 will be at the lowest point in the room and so should be the first of the stale air to exit the vent.
I think the larger concern should be on carbon monoxide readings where combustion is the source of heat in a household eg gas heaters, gas stoves, wood stoves, open fireplaces.
The article @Fred123 posted about CO2 meters was more in regards to portable ones when out and about in places like restaurants and shopping centres, in this regard it is about the human exhaled CO2 in a room or area and gauging the risk of COVID. A high reading would indicate that risk levels were higher as little fresh air is being put into that environment meaning that droplets containing virus could be in sufficient concentration to be more infectious. Lower levels meaning less risk and thus safer conditions. Noting nothing is perfect in this regard but it does indicate a level of risk.
There is a solution, commonly recommended for energy efficient homes that uses energy recovery to reduce losses while ensuring adequate ventilation.
There are some great points already about typical Australian homes. For most of the year Australian homes experience relatively mild conditions. There is no need to close up a home for warmth or cooling. Most of us can tolerate a range of temperatures and remain in comfort, clothing suitable. Shading and good insulation can only improve on the outcome.
RENEW from an older article offers an overview.
.
Yes, and add in fine particulates from incomplete combustion. Un-flued gas heaters are the pits, building up CO2, water vapour and possibly CO. Open fires and inferior (old) wood stoves produce much indoor air pollution too. I would rather get rid of such than have a machine tell me how bad it is or have another to try to get rid of it.
Thanks for the suggestion @Bongobec. We don’t have plans for a CO2 monitor test at the moment - for now, air purifier reviews are our focus when it comes to air quality. Other types of air quality related reviews may come in future.
Carbon dioxide monitoring
is becoming more widely spoken about as a way to help protect yourself from Covid 19 in smaller areas eg retailers, cafes, post lockdown.
By giving you an indication of how well ventilated the spaces are.
Was interested to find out what meets Australian Standards, if there are any, reliability of results.
Anyone have any experience with them.
Hi @OITNB, welcome to the community. I have moved your post to an existing thread which has also requested a CO2 monitoring device test.
I wouldn’t be making such claims at this stage. See some of the above comments in this regard.
It appears that poor ventilation can increase Covid transmission risks…and poor ventilation can also result in increased CO2 concentrations (but so can other things like burning fuels indoors, living in a high CO2 area etc). The science behind it is by association…poor ventilation may cause increased CO2 levels…poor ventilation may increase Covid transmission if one is in the same room as an infected person. Such may have some merit in building which are more or less sealed…like those which occur in very cold areas to prevent heat loss.
There is some advertising appearing in social media about using CO2 meters to protect against Covid. This may be more about providing an opportunity to increase sales of CO2 monitors.
