From the containment to the smaller parts like a handle and a hinge for a hvac, all of it matters when it comes to keeping the unit secure and safe from elements and people not meant to come in contact with it. Keeping it sealed means avoiding potential malfunctions, errors and other problems that may arise as a result of not keeping the HVAC unit secure from the elements and environmental hazards that may exist depending on where it is placed. Not only that, but you need to consider that a HVAC unit needs two to be opened in two stages, so that depressurizing can happen and allow you to get access without causing damage. Even the hinge for a hvac matter a lot for that, to help ensure that depressurizing can happen without any hitches along the way.
The heating, ventilation and air conditioning all help make the workplace more pleasant to be in, easier to work and perform your duties in. No one can work efficiently in too hot or too cold temperatures, though when you acquire and design the containment for the HVAC, you do need to keep the temperature and weather in mind and the smallest parts, such as a hinge for a hvac, help with that. Just make sure that the manufacturer you contact can hold up a high standard of quality and can fit your needs, sometimes you might even need something custom made so making sure that your manufacturer can accept custom solutions is important as well.