High CO₂ Levels in Apartment
This started out as a post on Mastodon, but I will be blogging about this more.
I have an interesting problem. Our apartment lacks adequate ventilation and our co2 levels are always high. I have monitors in multiple rooms and at night with the door closed our bedroom is around 1600-2000+ppm. The recommended levels are under 1000ppm. For adults its not great, but my wife and I are expecting our first in March. Prolonged co2 levels above 1500ppm increased risk potential cognitive effects and 2000ppm is unhealthy for infants. There aren't any laws or regulations around residential indoor air quality, so the apartment complex doesn't have to remedy the situation.
There are a few ways to deal with high levels of co2. The simplest is to open a window. But its winter in Carson City with the temperatures at night dipping into the low 20s, and an infant is far more susceptible to temperature than co2. It would require us to open a window across the apartment while using the HVAC to heat and circulate the air. Heating an open window means significant increase to our heating bill.
They do make specialized ventilators to solve this exact HVAC problem. A Heat Recovery Ventilator (HRV) and Energy Recovery Ventilator (ERV). A HRVs heats the incoming air using a heat exchanger. They are efficient with some units hitting 80-90% heat recovery. With the big draw back being outside humidity. ERVs on the other hand handle both heat and humidity. The issue is that no one makes an apartment friendly HRV or ERV. They required outside vents to installed though the walls and hooked up to indoor ducts.
If I want to go with a ventilator I have two options. Buy a residential unit and run ducts to a window with a DIY adapter. The units aren't cheap around $1500, and with the unit and ducts would take up a bit of room, not to mention ugly. It would take up a quarter of my home office.
The second option is a DIY HRV. An ERV would be the ideal, but it isn't feasible. I would have to go with a pre-made ERV core ($600-$1000) and the unit would be bulky. But a DIY HRV with custom core is do able. In order to eliminate most of co2 I need about 100CFM. I am thinking two small HRV cores vented to the window. HRV cores are two air streams that cannot mix going through heat conductive material.
I should also add that any solution is temporary. We are going to be moving to a house in 4 months.