On whether changes in bedroom CO2 levels affect sleep quality • Hacker News Board

Re: On whether changes in bedroom CO2 levels affect sleep quality

#111

Post by lomereiter » Mon, Jan 21, 2019, 10:12 PM UTC

treis wrote: post #97

SketchySeaBeast wrote: post #87

Earlier quoted context omitted.

> but it allows us to run the furnace less at night (heat from the lights) Dear God, what's your power bill? There's no way a LED lights heat is as efficient as just using the furnace. edit: I meant cheap, not efficient.

Theres no difference in heating efficiency for any source. Heat is heat and it doesn't really matter if it's generated from a heating element in a furnace or an LED light. And with the light you're at least getting dual use out of it. If they have a gas furnace it might be different but that would also depend on how their electricity is generated.

Your statement is true if the electricity is generated locally, otherwise there's a difference in energy losses depending on the carrier.

According to http://web.archive.org/web/20180822025250/https://portfoliom... heating with grid electricity would require 2-3 times as much primary energy as heating with water/oil/gas.

Re: On whether changes in bedroom CO2 levels affect sleep quality

#112

Post by graeme » Mon, Jan 21, 2019, 10:12 PM UTC

wnoise wrote: post #88

graeme wrote: post #75

Earlier quoted context omitted.

Good observation. That said, co2 and o2 should move pretty much in tandem if the source of high co2 is human breathing + limited ventilation, right? This could potentially account for why no ill effects of high co2 were found in submarines. Presumably o2 supply there is well maintained. Do household air quality standards include o2 levels?

They do move in tandem on a molar basis, but because there is so much more O2 in the air, even very high concentrations of CO2 have barely changed the concentration of O2.

Right, so then in a single night in a poorly ventilated room, a human would not breathe up enough of the O2 to make any difference in their functioning?

(Meaning we could rule it out as an explanation for the effects, if the effects do exist)

Re: On whether changes in bedroom CO2 levels affect sleep quality

#113

Post by graeme » Mon, Jan 21, 2019, 10:13 PM UTC

DocG wrote: post #78

graeme wrote: post #40

Earlier quoted context omitted.

What level was it at when you started noticing those effects? And how did you measure productivity? I have a sensor and try to keep readings low. My girlfriend isn't quite convinced though, especially in winter....

Around over 2000 I think. Less than 1000 would be ideal, I think outside is around 400.

Yeah it never gets above 1300 at our place with windows closed. With a window open a crack it stays at 700-1000.

Outside is 400 globally but often 450 or more in cities. At least on my meter.

Re: On whether changes in bedroom CO2 levels affect sleep quality

#114

Post by AngryData » Mon, Jan 21, 2019, 10:14 PM UTC

DocG wrote: post #29

I was lucky to get my hands on 5 proper co2 sensors from university, while I was teaching and working. So plenty of test places. What I found: -Just a couple of hours in a office, without ventilation spikes the co2 enough to make everyone dizzy and tired by the end of the day. Keeping eye on the meter and ventilating properly, increased everyones productivity and people werent so tired by the end of the day. - Classr…

As someone who has built my fair share of houses and worked on many more over the last 25 years, I have to agree that our ability to seal air better than ever is causing problems, especially if you don't have forced air heating and cooling running all the time. People just completely ignore or haven't ever thought about room ventilation, positive or negative room pressures, and where and how to ventilate to the outside. In older houses there was always air leaks, small, but they let the house breath, especially if you had a central fireplace and your house was at negative pressure. I have seen many people purposefully over seal their house in ill conceived ways, to try and improve insulation, but end up causing ventilation problems with mold being especially common. Materials and vents that should let air pass through are commonly replaced with impermeable plastics and sealing tapes, many times in conjunction with a misunderstanding in expansion and contraction joints that have small gaps.

Re: On whether changes in bedroom CO2 levels affect sleep quality

#115

Post by greenleaf2 » Mon, Jan 21, 2019, 10:15 PM UTC

hannasanarion wrote: post #83

greenleaf2 wrote: post #54

There's one big problem with this entire idea of co2 levels affecting sleep quality or humans in general: Even though there are cognitive effects of CO2, most often the CO2 levels in indoor rooms are simply a sign of low oxygen levels. In fact, there should be an inverse relationship between CO2 and oxygen in rooms. So an experiments would need to take this into account and supply pure oxygen to make up for the oxyge…

It should be noted though, that the effects of low oxygen are already very well known and well understood, thanks to decades of research funded by air and space agencies. It should therefore be pretty easy for CO2 researchers to control the outcomes of their experiments against the known physiological effects of hypoxia, to determine what effects are actually caused by CO2. And aside from that, the dosages being disc…

The symptoms of slight sub-clinical hypoxia are in line with the observed effects of people in high CO2 office rooms: headaches, concentration problems, tiredness, etc.

In a closed small room, the oxygen is mostly used up after a couple of days.

One person in a small tightly closed room will lower the oxygen level significantly, by 5-10% (consumption is around 20 cubic feet, and a small room has about 200 cubic feet oxygen in volume in total)

CO2 and oxygen work in tandem in the human body, and studies in the medical field have shown that an increase in carbon dioxide increases breathing rate, breathing volume, heart rate and metabolic rate.

The result is an increased need for oxygen, which will not be met in a closed room.

Thus I speculate that an increase in CO2 with an accompanying increase in oxygen (or at least a stable flow) will mostly negate the observed symptoms.

My preliminary working theory would be that the previously observed effects from high CO2 in rooms (office rooms for example) are due to the interaction of both high CO2 and low O2.

Re: On whether changes in bedroom CO2 levels affect sleep quality

#116

Post by SketchySeaBeast » Mon, Jan 21, 2019, 10:16 PM UTC

freetime2 wrote: post #105

SketchySeaBeast wrote: post #95

Earlier quoted context omitted.

I never considered an electric furnace - I come from a land of ice and snow and the only real option is natural gas.

I live in a land of ice and snow and we rely entirely on mini-split heat pumps in the winter [1]. Admittedly they do lose efficiency quickly when temps drop well below freezing, but they work well enough here. I have also seen some pretty cool looking "passive" houses that, due to excellent insulation, are able to heat the entire house with a 3kW furnace [2]. And these are in very cold locations (e.g. Alberta, Canada…

I live in Alberta - I love the idea of a passively heated house, but for now I'll stick with my 25 kW (converted from BTU) gas furnace. It's about 5 cents / kW for electricity and 0.5 cents for natural gas. That house would still cost more to heat. Sadly natural gas has a carbon footprint by default.

Re: On whether changes in bedroom CO2 levels affect sleep quality

#117

Post by quickthrower2 » Mon, Jan 21, 2019, 10:16 PM UTC

onychomys wrote: post #89

nkingsy wrote: post #69

This is especially pronounced at high altitude, and when running a furnace in the winter. I keep large black tents (4x4 ft or 2x4) in every bedroom in the house, and grow kale, spinach, chard, peas, tomatoes, etc inside (with handmade COB LED lights). I don't have any sensors to get a real idea of the difference in CO2 it makes, but it allows us to run the furnace less at night (heat from the lights), and makes a not…

Have the police visited? Sounds like the sort of thing they'd think would be a grow house. (....a marijuana grow house, I mean, not one for eggplants and radishes)

I reckon it would be tough growing eggplants indoors with LED light.

Re: On whether changes in bedroom CO2 levels affect sleep quality

#118

Post by [deleted] » Mon, Jan 21, 2019, 10:16 PM UTC

wnoise wrote: post #88

graeme wrote: post #75

Earlier quoted context omitted.

Good observation. That said, co2 and o2 should move pretty much in tandem if the source of high co2 is human breathing + limited ventilation, right? This could potentially account for why no ill effects of high co2 were found in submarines. Presumably o2 supply there is well maintained. Do household air quality standards include o2 levels?

They do move in tandem on a molar basis, but because there is so much more O2 in the air, even very high concentrations of CO2 have barely changed the concentration of O2.

[deleted]

Re: On whether changes in bedroom CO2 levels affect sleep quality

#119

Post by tux1968 » Mon, Jan 21, 2019, 10:17 PM UTC

graeme wrote: post #71

tux1968 wrote: post #46

Earlier quoted context omitted.

That's interesting, I was just linking the article because it was talking specifically about co2 and NASA recommendations. In fairness, it didn't give any hard numbers on what to expect.

I think the author of the piece just made a poor inference. Air cleaning isn't necessarily the same as lowering co2. That said, seems there are some succulents that do most of their co2 intake at night. Those would work best for co2. But you would need....at least 30-40 of them. Opening a window, by contrast, works extremely well, and quickly. However, this requires non-polluted outside air. Else you're exchanging lo…

Opening a window is just a bit too expensive in the -20 degree weather we're getting around here right now :-)

Re: On whether changes in bedroom CO2 levels affect sleep quality

#120

Post by greenleaf2 » Mon, Jan 21, 2019, 10:20 PM UTC

Symmetry wrote: post #106

greenleaf2 wrote: post #54

There's one big problem with this entire idea of co2 levels affecting sleep quality or humans in general: Even though there are cognitive effects of CO2, most often the CO2 levels in indoor rooms are simply a sign of low oxygen levels. In fact, there should be an inverse relationship between CO2 and oxygen in rooms. So an experiments would need to take this into account and supply pure oxygen to make up for the oxyge…

That's intuitively appealing but when you look at the numbers it's almost certainly false. When CO2 goes from 400 ppm to 1000 ppm then oxygen will go from 21000 ppm to 20400 ppm, a 3% drop which isn't going to be enough to change anything.

No, the body does not use the same amount of oxygen, as the amount of CO2 it exhales.

The amount of oxygen used is way higher.

A person consumes 19 cubic feet of oxygen a day.

Edit: I looked at the composition of inhaled and exhaled air, and now I realize the reason O2 is being taken out of the air in higher amounts than CO2 is introduced, is that the exhaled amount of carbon dioxide is not the total amount of carbon dioxide that has been created in the body.

When the CO2 in the room gets higher, more CO2 is actually taken up again from the room back into the human body, with the exhale rate staying relatively constant. Or in other words, a significant part of the increase in CO2 in the system human room is actually in the human, not in the room. The room measurement thus covers only a part of the CO2 being produced in total, and only the unknown total amount of CO2 produced reflects the totality of O2 being used up.

This means a change of 1000 ppm of CO2 in the air will mean a higher amount of oxygen has been used up.