Are your doors wasting your food plant’s energy?

How unfit doors can increase utility costs and diminish energy savings.

By Darren Ross May 6, 2016

Did you know a single weak link in your building envelope can have a major impact on your food plant’s energy efficiency? Take your facility’s doors and door openings. In an otherwise well-insulated and well-designed facility, an improperly designed door opening can erase a big portion of energy and utility savings. Your entire building envelope, from the windows to the walls, must be tightly sealed to achieve the utmost energy efficiency—including the doors.

Installing the proper door will have a positive impact on your facility’s energy costs and productivity, while an improper door can result in:

  • Wasted energy
  • Increased utility costs
  • Downtime
  • Costly damage
  • Possibly unsafe conditions.

To determine the most appropriate door types and materials for your facility, your design firm should examine all aspects of your plant’s operations.

Five questions to facilitate energy-efficient doors

Answer these five questions to ensure your doors and door openings facilitate the most energy savings for your food processing plant:

1. What are the operating temperatures within your food plant? Consider the normal and extreme operating parameters of your food plant to ensure doors are equipped to withstand the conditions, including humidity. For example, if you have doors in an area with below-freezing temperatures, you’ll need heated components to prevent the door from freezing shut and to keep elements (such as gasket seals) pliable. You may also incorporate nonheated design features with integral thermal breaks into the construction of this door, which reduces the electrical energy needs of the door. Controlling high-humidity areas, on the other hand, increases the need to decrease airflow by reducing the time the door is open through higher opening speed or by using horizontal air curtains.

2. What is the opening frequency of your door? In other words, how many times per day and per hour will your door be opening? This could influence the desired speed of the door operation and its suitability for high-cycle applications. For example, a low-cycle door on a cooler may only require traditional insulation with high R-value panels, whereas high-cycle door openings shift immediately toward high-speed motorized operation or air curtains for ultra-high cycles. The shorter time the door is open, the more energy savings you’ll experience.

3. How will your door be used? Will forklifts, motorized pallet jacks, push carts or personnel be passing through the door? This affects the opening size and could impact the opening and closing speed. Similar to the opening-frequency factor mentioned above, the size of the opening—especially height—can have an impact on air movement and energy efficiency. An improperly sized door opening could result in air leakage and energy loss.

4. What are the area’s clearances? Room layout and structure may prohibit some door types that require side or head clearance. Doors with housing frames and those that swing or slide open need additional clearance space. Just because the most energy-efficient door selection for a given application may be restricted clearance-wise, there may be door types with other efficiency features that could be more energy-efficient. For example, if a door application is limited due to very narrow side clearance, there is still a variety of vertical or roll-up doors available with beneficial features, such as:

  • High-speed operation
  • Insulated panels or fabrics
  • Slim side columns.

The same can be said for vertical-clearance-limited openings. Door options for horizontal sliding or bi-parting doors may include features such as:

  • High-speed operation
  • Well-insulated and sealing door panels
  • Door panels that can withstand an impact.

These features can all help provide an energy-efficient opening.

5. What is the pressure differential? Significant pressure differences can eliminate some door types or affect the way they are constructed. A higher pressure differential can cause rapid air changes and result in possible condensation and/or ice formation. For example, an ultra-high-cycle opening that separates different temperature and pressure conditions could be a candidate for a horizontal air curtain to facilitate energy savings; however, it may not work in excessive pressures. In this case, since it exceeds the allowable pressure differential that the door can accommodate, your solution may be limited to a physical barrier door (or a hybrid door using both[VS2] ). In this case, the barrier or hybrid door may be the most energy-efficient option for the application.

– Darren Ross is a senior project manager at Stellar. This article originally appeared on Stellar Food for Thought. Stellar is a CFE Media content partner. Edited by Erin Dunne, production coordinator, CFE Media, edunne@cfemedia.com.

Stellar is a CSIA member since 11/30/2015.

Original content can be found at stellarfoodforthought.net.