Ventless heaters do not vent air outside the room. It will warm the room at a reasonable speed. You won’t have power during a blackout, but the system will be much cheaper. However, they may still use a lot of electricity depending on its power and how long you have it on for. There are several controversies associated with the use of ventless gas heater. There is no accompanying loss of heat. The electric garage heater needs to be hardwired (rather than plugged in), which means it requires an experienced electrician to be properly installed, but on the plus side, the relatively small size of this heat unit means it can be installed and mounted in a variety of locations. Battery packs like these are great for charging phones and laptops, as well as running fans, LED lights, CPAP machines, and other small devices. This is especially true for devices like refrigerators and A/C units. In particular, you probably want a "pure sine wave" inverter, as not all devices will work well (or at all) with square or modified square wave inverters. These work well in insulated spaces. Heated floors work differently than other forms of heating.
