Unventilated bedrooms

[bagofpucks]

Looking to the CP hive mind again...and hopefully something to get some folks’ off of covid!

Our house has three bedrooms in the basement that are unventilated. There are three heating vents in the main areas, but not in the bedrooms. The basement is heated primarily by radiant in floor heat, which works pretty well, but I do keep an eye on each room temperature as the system is a bit finicky.

My main question is about air flow. Each bedroom is quite large and has large windows. I’m concerned about oxygen/C02 levels in the night when people are sleeping and the doors are closed. The doors are standard and have cracks underneath them, so obviously the rooms are not perfectly sealed.

Am I overthinking this? The house has been inspected a few times and obviously is to code. I guess it would be the same in any bedroom if you’re not running your furnace or AC at a certain time of year. Is it worth it to grab a C02 detector just to be safe?

[transplant99]

nm...wrong thread

[bagofpucks]

Sorry, no, not worried at all about covid! Just about general health of sleeping in the rooms!

[You Need a Thneed]

CO (carbon monoxide) is what you need to worry about, not CO2 (carbon dioxide).

Breathing doesn’t create CO.

The rooms aren’t sealed, I can’t see how oxygen levels could ever get down to dangerous levels.

[Brick]

C02 does build up and ventilation is a good idea. Opening the windows periodically would help. You can also get a C02 monitor if you are concerned.

Personally, I use an air quality monitor that measures PM 2.5 and CO2. It tells me when to open windows, use an air purifier, etc. Mine comes from IQAir Air Visual and is a bit pricey, but accurate. You can get inexpensive ones at other places, just not sure how accurate they are. You should do your own research but that's what I came up with.

[rbochan]

Originally Posted by bagofpucks

...Am I overthinking this?...

[Fuzz]

I don't think you are overthinking it, it is something to be concerned about. I can't link the images, but follow the link for some good graphs.

Quote:
High CO2 concentrations reduce our cognitive performance, our health, and our comfort*. High CO2 levels during sleep are associated with low comfort based on subjective measures of air freshness, mental state, restedness, and mouth/skin dryness [Strøm-Tejsen 2016]. In schools in Washington and Idaho, elevated CO2 levels are associated with increases in student absences: A 1000 ppm increase in CO2 concentration leads to a 0.5–0.9% reduction in annual average daily attendance [Shendell 2004].


Even astronauts suffer: On the International Space Station, the odds of a crew member reporting a headache double for every 1300 ppm increase in CO2 concentration [Law 2014]. And it’s hard to keep CO2 levels low in an airtight box filled with people.
https://medium.com/@joeljean/im-livi...ly-b7c391e8ab6

[Dynamic]

I think you may be overthinking it. This is actually the first time I’ve even thought about the possibility of C02 buildup. I’m sure by now there would be a PSA about it. I’m pretty sure any room in a house will not be sealed enough to not allow some air circulation.

That being said if your in a complete sealed vessel such as a capsule in space it is very important. In the Apollo 13 accident IIRC they were dealing with an issue of not being able to filter out the C02 and had to build something from scratch to accomplish that.

[guzzy]

just make sure you have 1" clearance under the 3 bedroom doors. If you have a cold air return in the basement it will pull air like a vacuum from the rooms when doors are closed. 1" is code if cold air returns are not present in bedrooms in basement.
If you don't have 1", remove the door from hinges and get your saw out. Sand and put back up. Easy fix

[Fuzz]

Originally Posted by guzzy

just make sure you have 1" clearance under the 3 bedroom doors. If you have a cold air return in the basement it will pull air like a vacuum from the rooms when doors are closed. 1" is code if cold air returns are not present in bedrooms in basement.
If you don't have 1", remove the door from hinges and get your saw out. Sand and put back up. Easy fix

How does it pull air out of the rooms when there is nowhere for air to enter? If it is a well sealed room you won't have airflow.

[bagofpucks]

Thanks everyone for the feedback!

Each door has a 1/2 to 3/4 inch opening at the bottom. guzzy - could you send me the code that you know or for the 1 inch minimum?

I chatted with our HVAC installation guy and he said there is absolutely no concern as long as there are vents and cold air returns in the common areas, which there are. For sanity sake, I may pick up an air quality detector that includes C02 detection.

[8 Ball]

Pretty sure you need supply air and return air for each bedroom.

[guzzy]

Originally Posted by bagofpucks

Thanks everyone for the feedback!

Each door has a 1/2 to 3/4 inch opening at the bottom. guzzy - could you send me the code that you know or for the 1 inch minimum?

I chatted with our HVAC installation guy and he said there is absolutely no concern as long as there are vents and cold air returns in the common areas, which there are. For sanity sake, I may pick up an air quality detector that includes C02 detection.

i used this:
https://www.chestermere.ca/DocumentC...ackage-?bidId=
Bottom of page 3. I am sure the same is for Calgary.

[guzzy]

Originally Posted by Fuzz

How does it pull air out of the rooms when there is nowhere for air to enter? If it is a well sealed room you won't have airflow.

You are correct. I missed the part where they said they didn't have heat vents.

[Scroopy Noopers]

Originally Posted by 8 Ball

Pretty sure you need supply air and return air for each bedroom.

For sure. Return air can be provided under the door as guzzy mentioned, but you need a supply.

[opendoor]

Many building don't have any kind of forced air systems (i.e. ones that use baseboard heaters, radiators, etc.) or are in temperate climates where heating/AC is only used for part of the year. So there's no real safety consideration in not having air circulation in a bedroom. Unless you have a dozen people packed into a bedroom, the space under the door and gaps in the building envelope provide more than enough fresh air to keep it safe.

Air quality can suffer a bit and smaller rooms can get a little stuffy at night, which is one of the reasons people use HRV/ERVs now. But in terms of safety, it's not a worry at all unless there's some other issue with the air quality.

[Rulakir]

Originally Posted by bagofpucks

Thanks everyone for the feedback!

Each door has a 1/2 to 3/4 inch opening at the bottom. guzzy - could you send me the code that you know or for the 1 inch minimum?

I chatted with our HVAC installation guy and he said there is absolutely no concern as long as there are vents and cold air returns in the common areas, which there are. For sanity sake, I may pick up an air quality detector that includes C02 detection.

I'd be careful about taking everything the installation guy says as being 100% accurate as a lot of them are either misinformed or don't want to do the extra work.

I'm not sure which edition of the building code you'd want in your situation but it typically doesn't change much for the sections relevant to residential occupancies. Generally speaking:

• You need to have ventilation air provided (e.g. outside air) to help with indoor air quality.
• Depending on whether it is non-heating season vs heating, ventilation can be provided through natural means (e.g. opening a window) or mechanical means (e.g. forced air via furnace, heat recovery ventilator, etc).
• For non-heating season, ventilation is permissible via natural or mechanical means.
• For heating season in our climate, ventilation air is handled by mechanical means (e.g. furnace, heat recovery ventilator) as it will temper the air before it is circulated to habitable spaces -- and yes, it is a requirement to temper the air.

In your case, you mentioned that you have a radiant in-floor heating which is fine for warming the space but it doesn't do anything for ventilation in the heating season. The purpose of having an undercut for the door is to allow air to pass out of the room in lieu of having a return duct inlet at the room. (Typically it is "easier" construction to have the minimum single return duct inlet in the common area on each floor.) No, the building code does not explicitly indicate the size of this undercut but 1" is generally an accepted standard for residences.

With no air being introduced into the room, the undercut for the door doesn't do much at all for air circulation and introducing ventilation air into those bedrooms when the doors are closed. Even when the doors are open, there isn't necessarily much ventilation air for those bedrooms as you'd just have "dead pockets" with the air supplies and air return in the common area essentially bypassing/short-circuiting those rooms.

Does this create a problem for your place? I guess it depends on if you're comfortable with it. Was it done right/wrong if it passed post-occupancy inspection as well as any reviews during construction prior to occupancy? That's not for me to say as things often get overlooked and it can vary with each person.

I will add one extra comment though -- if radon becomes a concern, it'd be nice to have air circulation available year-round in those spaces!

[bagofpucks]

I am monitoring Radon, so no concerns there.

Thanks again for all the feedback folks! We do have great windows down there, so we do open them up from time to time to get some air moving. I don’t find it stuffy in any of the bedrooms, but just wanted to make sure we were covering off all the bases.

[Scroopy Noopers]

Another consideration for dead air space is moisture accumulation (leading to mold). Although that’s much more of a concern here in Ontario than dry ass Calgary!

[Fuzz]

Originally Posted by Scroopy Noopers

Another consideration for dead air space is moisture accumulation (leading to mold). Although that’s much more of a concern here in Ontario than dry ass Calgary!

We are truly blessed out here.