In addition to a walk-in cooler and freezer, a convenience store in particular, often has a variety of small reach-in glass door merchandisers, sometimes called novelty coolers, . They are often installed for free by the manufacturer or distributor of the products they contain and who retains ownership of them. However, the storeowner must pay for the electricity to run them, which often amounts to hundreds of dollars a year for each merchandiser and makes their efficiency a real concern.
These coolers usually have four or fewer sliding or hinged doors and are arranged around the perimeter of the store to offer a variety of refrigerated products to the customers. Like household refrigerators, most come with self-contained refrigeration systems that add heat and noise to the sales space. The heat becomes an added cooling load for air conditioning to remove, but can reduce the need for heating in the winter. Because such merchandisers have power cords and are complete systems of integrated components, ENERGY STAR® ratings are available and more efficient models can be identified. Larger units are sometimes connected to remote condensing units like walk-in coolers are, which improves air conditioning efficiency, but not space heating efficiency, by removing the heat from the store.
The DOE has issued updated energy standards for commercial refrigeration equipment that are being phased in from 2010 to 2017 and will make the average refrigeration unit 30% more efficient than those meeting the old standards.
A significant savings can result from a control device that shuts the lights and refrigeration off in a merchandiser at night, as long as it is filled with product like soda that can tolerate such periodic warming and cooling. Like a setback thermostat that allows the heating or cooling of a house to be reduced when the occupants are asleep or away, a merchandiser control saves energy by not having a mechanical system work so hard. Dairy products and other such perishable products need to stay cold around the clock and cannot benefit from having the refrigeration turned off. Merchandiser controls can be either stand-alone or connected to larger electronic controllers, a Freeaire® Cooler Controller being one example. A simple on/off timer located at the outlet on the wall behind a merchandiser can keep the unit off when the store is closed, but will get out of sync when power outages occur and can be very inaccessible, so an electronic controller with a battery to power the clock and retain the settings when power is lost is a better alternative.