I have implemented better space handling in helm-ag. If you want to input pattern which contains space, you can use escaped space like pattern1\ pattern2. Such pattern matches lines which have pattern1 pattern2. (While pattern1 pattern2 matches lines which have both pattern1 and pattern2.
Example
First I input apple orange. This pattern matches all lines because all line have both apple and orange. Second I input apple\ orange, first and third line are matched but second line is not matches because second line does not have apple orange