With electric fireplaces, or at least those that aren’t purely ornamental and actually do provide heat, you’ll mostly treat as you would any space heater. You’ll want to keep it away from anything particularly flammable, of course; don’t pile your laundry up against it, for example. Any kind of ventilation required will typically be handled by the design of the fireplace. That is, they’ll have built-in a way of ventilating the heat that will be effective in its design without you having to do anything extra. You won’t need to install or use a chimney or any ventilation pipes. You can even place some electric fireplaces in your old fireplace or directly on your drywall. Just follow the directions that the manufacturer details.