### Craft 2

Either of these should work (they are equivalent):

    {% set entries = craft.entries.width('> 0').section('windows').order('width') %}

or

    {% set entries = craft.entries({
      section: 'windows',
      order: 'width',
      width: '> 0'
    }) %}

The reason you are getting "Array to string conversion" error is that [find](https://craftcms.com/docs/templating/elementcriteriamodel#find) has turned your [ElementCriteriaModel](https://craftcms.com/docs/templating/elementcriteriamodel) into an array.

### Craft 3

`order` is now `orderBy`

Craft 3 Docs: [Element Queries](https://craftcms.com/docs/3.x/element-queries.html)