This is a workaround for search center refinements in SharePoint 2013. The bug is that the search center takes the browser language, instead of the default language of the SharePoint farm.

search-lang-sp.js

//This is a workaround for search language. Please remove this after the August Patch has been installed (SharePoint 2013, 2013 CU)
//A control for changing the language adds a url fragment: #l=1033 (for English)
// bug #2319
(function() {
    var href = window.location.href;
    var url = window._tpContextInfo.SearchCenterUrl;
    var searchCenter = href.indexOf(url + "/results.aspx") === 0 || href.indexOf(url + "/peopleresults.aspx") === 0;
    if (searchCenter) {
        var hash = window.location.hash;
        var langRegexPattern = "#l=\\d{4}";
        var langRegex = new RegExp(langRegexPattern);
        var englishRegexPattern = "#l=1033";
        var englishRegex = new RegExp(englishRegexPattern);
        var hasLangHash = langRegex.test(hash);
        var hasEnglishHash = englishRegex.test(hash);
        if (!hasLangHash) {
            window.location.hash += englishRegexPattern;
        } else if (!hasEnglishHash) {
            window.location.hash = hash.replace(langRegex, englishRegexPattern);
        }
        var getParameter = function(key) {

            function parseParams() {
                var params = {},
                    e,
                    a = /\+/g, // Regex for replacing addition symbol with a space
                    r = /([^&=]+)=?([^&]*)/g,
                    d = function(s) { return decodeURIComponent(s.replace(a, " ")); },
                    q = window.location.search.substring(1);

                while (e = r.exec(q))
                    params[d(e[1])] = d(e[2]);

                return params;
            }

            if (!this.queryStringParams)
                this.queryStringParams = parseParams();

            return this.queryStringParams[key];
        };
        //adjust the query string keyword ?k= Copy it to the hash
        // if there
        if (/k=/.test(window.location.search) && !/#k=/.test(hash)) {
            var value = getParameter("k");
            window.location.hash += "#k=" + value;
        }
    }
});//decided not to implement this fix//();