A great option for keeping CO2 levels down in a house is with an HRV (or ERV) [1] that will heat the fresh air coming in to cycle it throughout the house.
> During the warmer seasons, an ERV system pre-cools and dehumidifies; During cooler seasons the system humidifies and pre-heats.[1] An ERV system helps HVAC design meet ventilation and energy standards (e.g., ASHRAE), improves indoor air quality and reduces total HVAC equipment capacity, thereby reducing energy consumption.
> ERV systems enable an HVAC system to maintain a 40-50% indoor relative humidity, essentially in all conditions. ERV's must use power for a blower to overcome the pressure drop in the system, hence incurring a slight energy demand.
In Jan 2023, the ERV wikipedia article has a 'Table of Energy recovery devices by Types of transfer supported': Total and Sensible :
> [ Total & Sensible transfer: Rotary enthalpy wheel, Fixed Plate ]
> [ Sensible transfer only: Heat pipe, Run around coil, Thermosiphon, Twin Towers ]
Latent heat: https://en.wikipedia.org/wiki/Latent_heat :
> In contrast to latent heat, sensible heat is energy transferred as heat, with a resultant temperature change in a body.
Sensible heat: https://en.wikipedia.org/wiki/Sensible_heat
There's a broader Category:Energy_recovery page which includes heat pumps. https://en.wikipedia.org/wiki/Category:Energy_recovery
Are heat pumps more efficient than ERVs? Do heat pumps handle relative humidify in the same way as ERVs?:
I did not 3D print mine, but ordered it, though as an early adopter, adjustment was required.