Electric heaters don't dry the air. The cold air outside the home doesn't hold that much moisture, so the humidity gets drawn outside the home leaving the air dry. Electric heaters also don't burn anything so they don't deplete oxygen. Unvented gas heaters/stoves do produce moisture as a byproduct of the combustion process, but they also deplete oxygen in the combustion process. Vented fuel heat like furnaces, fireplaces, and stoves in good, operational condition will draw in dry, but more oxygen rich air from the outside as it gets drawn up and out the chimney or flue. Newer stoves and furnaces may directly draw in air from the outside so the indoor air should have similar humidity and oxygen characteristics to that of electric heat.
Electric heaters don't dry the air. The cold air outside the home doesn't hold that much moisture, so the humidity gets drawn outside the home leaving the air dry. Electric heaters also don't burn anything so they don't deplete oxygen. Unvented gas heaters/stoves do produce moisture as a byproduct of the combustion process, but they also deplete oxygen in the combustion process. Vented fuel heat like furnaces, fireplaces, and stoves in good, operational condition will draw in dry, but more oxygen rich air from the outside as it gets drawn up and out the chimney or flue. Newer stoves and furnaces may directly draw in air from the outside so the indoor air should have similar humidity and oxygen characteristics to that of electric heat.