Adding it to Application Helper and calling in your _header.html.erb
is the actual way of implementing.
Instead if you wanted to do it without risk, you can directly include the logo by editing the application.html.erb
and adding the
<img style="" src="/system/images/Wsdsds/logo.png"/>
before or after
<%= render "/refinery/header" -%>
as you wish and this will be shown to every page where the header id refers. Similarly you can overwrite any view files.
In case, if the _header.html.erb
is invisible you can easily make it visible by using the refinery override,
$ rake refinery:override view=refinery/*