Try Student Accomodation - it’ll be mainly empty in Summer.
I know a young fella came up for a Summer job to Dublin last year and
got a nice place near Smithfield in a student residence - only 3 in a place for 5.
Enquired thro’ his college and was referred by DIT to the private managment
of the residemce.
Presumably. southside DIT, UCD or Trinity have similar links.
There’s a company called ‘home from home’ that operate in my area. (Sandymount) I believe they do short term lets but they might be pricey as I think they are aimed at corporate lets. You can get short term rentals through daft. Depending on type of property there should be availability in the area