When it comes to finding the right HVAC system for your building, it can be challenging to find the right balance between high-quality performance and meeting sustainability goals.
To make the best decision, building owners have to compare the purchase and installation price, operational cost and projected life expectancy of the equipment. Often, the most energy-efficient equipment can cost more to install up-front but also offer significant savings in operational costs over the long term.
On the other side of the equation, less efficient equipment may end up costing less initially but will use more energy during day to day operations. It is also important to understand the kind of maintenance the equipment will need and whether it would require the services of a specialized technician. All those elements factor into determining the most economical option for meeting sustainability goals.
When evaluating HVAC equipment, one common mistake is to review only the full load efficiency of a system. To ensure that enough heating or cooling capacity is available, the consulting engineer will size the HVAC equipment for the worst-case conditions. Very rarely, however, (perhaps only 2 percent of the time), will the HVAC equipment ever need to handle those extreme conditions in its day to day operation.
This makes it very important to evaluate the part-load efficiency of both the HVAC equipment selected and the system as a whole. By utilizing HVAC equipment that can efficiently modulate capacity to match the heating or cooling demand, the part-load efficiency of the system will increase. This not only means reduced operating costs, but it also has a positive effect on the indoor air quality experienced by the building’s occupants.
Correctly sizing the equipment for the needs of the space prevents it from having to cycle on and off frequently. This reduces temperatures swings, helps provide better dehumidification, and can lead to an increased operating life expectancy for the HVAC equipment.
Meeting Ventilation Needs
One of the key features of HVAC systems needed for lodging and hospitality applications is the ability to introduce large amounts of ventilation air into the building due to the high volume of occupants. It is important to select equipment that can properly heat, cool, and dehumidify this ventilation air efficiently at part-load.
Features such as digital scroll compressors and electronic expansion valves help HVAC equipment modulate cooling capacity as necessary and maintain tight control over the supply air temperature. Condensing indirect-fired furnace technology, which is now available on rooftop equipment, increases the thermal efficiency of the HVAC equipment above 90 percent during heating mode. This substantially reduces operational costs compared to standard gas furnace options, which are at about 80 percent thermal efficiency, and reduces CO2 emissions. In some areas, condensing furnace technology may also qualify for rebates from utility companies, providing further benefit to the building owner.
Finding the Right Balance
Building owners don’t have to give up sustainability goals to find the best HVAC equipment to meet the needs of their spaces. It might take some homework and attention to details to identify the right one, but there are high-efficiency HVAC options available that also offer the high performance needed to serve large facilities.
Joseph Ellison is Sales Manager, Engineered Products, for Modine.