Can I use a Portable Air Conditioner without an Exhaust Hose?

If you need to cool a room, then you MUST use an exhaust hose with a Portable Air Conditioner. The exhaust hose removes heat emitted from the Portable AC. As your Portable Air Conditioner removes heat form the air inside your room, it blows heat through the exhaust hose and vent.
If you DO NOT use an exhaust vent, window installation kit or exhaust hose; your portable AC will not cool your room. It will blow heat right back into the space.