Download via Iframe // wo refresh
<a href="" id="csv-export">export</a>
<iframe id="downloadIframe" src="" style="height: 0px; width: 0px; display: none;"></iframe>
<script>
$("#csv-export").click(function(e){
e.preventDefault();
oIFrm = document.getElementById('downloadIframe');
oIFrm.src = '' // URL to download file -- via php download headers;
});
</script>