javascript – Counting the quantity of objects in an array containing a certain key with no empty value

The title says it all, here is my source code:

// start at zero
var count = 0;
// loop the elements
for (var i = 0; i < hours.length; i++) {
  // 1. check to see if the current item has a key called "description"
  // 2. check to see if the current item's "description" key isn't empty
  // NOTE: white-space only values aren't valid
  if(hours[i].hasOwnProperty("description") && hours[i].description.replace(/s/g, "").length > 0) {
// increment the account (by one)
count + = 1;
}
}
// return the account
return account;

When we remove comments, the code looks like this:

var count = 0;
for (var i = 0; i < hours.length; i++) {
  if(hours[i].hasOwnProperty("description") && hours[i].description.replace(/s/g, "").length > 0) {
count + = 1;
}
}
return account;

This seems to be quite expensive (especially for large tables). Is there a better way (preferably more concise) to count the number of objects in an array containing a certain key that has no empty value?

INFO: I can not use jQuery or LoDash / Underscore, all methods must be natively available in the browser and have good browser support (IE8 +), thanks.