Being green. That statement conjures up different images for many people. When my grand kids were young, every Saturday we would sit and watch Sesame Street. With slumped shoulders and his head lowered, Kermit the frog would sing “It’s not that easy being green.” But, that’s not necessarily true these days. Being Green is not only easy, but it’s smart, economical, environmentally sound, and politically correct.
As a well-experienced HVAC designers, we’ve seen an evolution in heating, ventilation and cooling applications and the manufacturing of these systems. The old ways of designing and specifying inefficient systems are as outdated and impractical as single-pane glass windows. Energy codes today are more demanding. HVAC equipment must be more energy efficient and ventilation systems must be designed to prevent the “sick building syndrome,” which basically describes situations in which building occupants experience acute health and comfort effects that seem linked to time spent in a building, but no specific illness or cause can be identified, according to the US Environmental Protection Agency.
The old ways of designing and specifying inefficient systems are as outdated and impractical as single-pane glass windows.
Facility owners are getting on the “Green Wave.” They’re demanding high-efficiency systems in their buildings for all the reasons mentioned above. So, engineers and HVAC equipment manufacturers are responding. Engineers are performing life cycle analyses that help owners determine the correct HVAC system for their “green” buildings. Meanwhile, manufacturers are busy meeting the demand with innovative equipment design and highly energy efficient equipment, such as closed-loop ground-coupled heat pump systems (Geothermal) and variable refrigerant volume (VRV). These and many other HVAC systems on the market will assist buildings in “being green.”
Illustration of a vertical loop heat pump system
The popularity of Geothermal is becoming more widespread. As the name would suggest, Geothermal uses the earth as a heat source. Plastic pipe is buried horizontally or vertically in earth “wells” for thermal contact with the earth. The indoor unit is usually a water-to-air heat pump. The process works when “water is circulated through the pipe, transferring thermal energy to or from a water-to refrigerant heat exchanger in the heat pump. The heat exchanger serves as the condenser or the evaporator, depending upon whether the heat pump is in a cooling or heating mode” (ASHRAE Design/Data Manual). ASHRAE Handbooks provide more in-depth information concerning ground source heat pump systems.
In the Louisville area, wells are typically 400 to 500 feet deep and can provide approximately 2.5 to 3 cooling tons per well. This system provides simultaneous cooling/heating. Individual temperature control zones within the building can be accomplished by installing heat pumps with or without air distribution duct work. Ventilation is generally provided utilizing a separate outside air unit with energy recovery units. Water-to-water heat pumps can be used for domestic water heating. In the Louisville area Geothermal systems can cost between $20 and $23 per building square foot. Luckett & Farley has recently designed a number of these systems for Fort Knox Military complex.
Perhaps lesser known to the general public is the VRV system. It uses fans to heat and cool. More specifically it consists of indoor ducted or duct-free fan coil units having refrigerant coils and remote outdoor condensing units with high-efficiency variable speed “inverter” compressors. This system can also provide simultaneous cooling/heating. The VRV system utilizes a one refrigerant pipe network. It is a very quiet system and only requires refrigerant pipes running between the indoor fan coil units and the remote outdoor compressor unit. It also reduces the amount of sheet-metal duct work. The VRV system also frees up valuable space above the ceiling. Luckett & Farley recently designed a State/Federal project using the VRV system. This system cost $18.00 per building square foot.
So, for all the facility owners out there, Luckett & Farley can help make it easy being green. Give us a call at (502) 585-4181. As for Kermit, well, keep your chin up. The world is going green with you.