The cost of purchase and installation is usually the main concern for engineers and building owners when evaluating a new HVAC system for a facility, but this is only one part of the equation for picking the right one.

Even the highest-end HVAC systems won’t perform well if there is a mismatch between their capabilities and facility requirements. Here are four important questions to ask at the start of the process when evaluating systems.

1)   How tightly does temperature and humidity need to be controlled within the facility?

When designing an HVAC system for a facility, it’s vital to know the specific load requirements for meeting the needs of a space. For example, a medical building will have different temperature and humidity requirements than a warehouse.

When calculating the true HVAC system load required to meet the needs of the facility, avoid using rules of thumb — underestimating or overestimating the load causes problems in the long run. Oversizing the HVAC equipment relative to facility needs can lead to occupant discomfort, temperature swings and short cycling. If undersized, the system may not be able to keep up with demand.

2)   Can the HVAC equipment handle humidity requirements for the facility?

If a building or zone exceeds 60 percent relative humidity, it can cause discomfort and mold growth issues. Because the use of outdoor air for ventilation can significantly increase the moisture content within a building, it’s important to factor in the total capacity of the system to reduce humidity. It’s costly to make up the difference with supplemental equipment after the fact.

3)   How much will it cost to maintain the HVAC system?

Something else to keep in mind when calculating the operation costs for HVAC systems: the routine maintenance needed to keep them running at full efficiency. If your maintenance staff does not have the technical know-how to maintain equipment, the cost of service contracts or frequent service calls from outside vendors can add up quickly. It’s important to choose a system that is reliable and that in-house staff can easily maintain.

4)   If the project is a retrofit, are there space or weight constraints for HVAC equipment?

Be sure to evaluate the physical dimensions and weight of any HVAC system you’re considering. If you are planning to retrofit your commercial facility with a new system, the equipment needs to be able to integrate into the existing space to avoid the need for costly renovations.