The short answer: it depends on your situation. A heat pump will usually cost more upfront, but it will handle both your heating and cooling needs efficiently in areas with mild climates and short winters. If you live in a cold climate area you may need auxiliary heat, making things more expensive than a more commonly paired system of an AC and furnace. If you already have an efficient heating system and only need to add cooling, your best bet is to go with a regular air conditioner. Ultimately, you should weigh the costs and benefits of a heat pump vs. an air conditioner.