I think they were suggesting a window unit air conditioner based on the price quoted. They can be installed without any modification to your home and you can take them out in the winter and put them in storage.

In terms of running them in reverse, there are already window unit heat pumps which tend to be a bit more expensive. Personally I'm waiting for the Gradient window unit heat pump to come out since I like the idea of the saddle-bag design and I want the heat pump capabilities, but I'm going to wait for reviews first since afaik this is their first product.