HVAC Systems


HVAC System design installed at the Green Lake County Justice Center

Ahern has been designing, installing, and servicing HVAC systems since the company's inception over a century ago. Our team of professional engineers, licensed designers, experienced project managers, and skilled foremen can bring your next HVAC project from idea to reality. Ahern designs, installs, and services the following partial list of systems. If you don't see the system you're looking for, please contact us for further information or visit our HVAC Services page to see what our skilled technicians can offer.

Central Air Handling Units provide conditioned, ventilation, or heated-only air to service a building. Systems can be located within the building or be roof mounted, and can provide constant air volume or variable air volume flow throughout the building.

These central plants provide chilled water to condition a facility. Chilled water cooling plants may be limited to serving one building or utilized to service several buildings.

Computer Room Cooling Systems provide either air or fluid cooling to condition the equipment located within a computer room.

These systems recover waste heating or cooling from exhaust air streams, and utilize it to pretreat incoming ventilation air into the building.

These systems provide exhaust from a building for safety or environmental uses, such as toilet exhaust, kitchen exhaust, smoke system exhaust, process exhaust, etc.

Fan Terminal Perimeter Heating Systems utilize perimeter terminal boxes that incorporate a fan to ensure constant air movement during the heating cycle. Heating can be provided by electric heat or hot water heating coils.

Geothermal Heat Pump Systems utilize the ground or a body of water as a heat source to draw from or add to within the circulation of condenser water in a heating/cooling system.

These central plants provide hot water to heat a facility. Hot water heating plants may be limited to serving one building or utilized to service several buildings.

Make Up Air Heating Systems introduce 100% outside heated air to spaces to offset the effects of infiltration or exhaust loads.

These systems are based on packaged heating/cooling HVAC units that can be located on a roof, on slab, or within the building to condition the building.

Perimeter Hot Water Heating Systems utilize hydronic hot water heat to warm the perimeter spaces. These systems include fintube radiation, radiant floor heating, radiant ceiling panels, or perimeter terminal units.

Steam Heating Plants are central plants that provide steam to heat, humidification, or sterilization for a facility. These plants may be limited to serving one building or utilized to service several buildings.

These systems circulate hot and chilled water to numerous individual units equipped with fans and coils to provide terminal temperature control of spaces. Two or four pipe fan coil systems are similar to those utilized in hotels, dorms, apartments, etc.

These systems utilize local terminals to vary the amount of air provided to differing spaces within a building to keep them comfortable based on occupancy, building orientation, internal loads, etc.

VRF Systems utilize the flow of refrigerant from a central condensing unit plant to numerous individual air handling units to provide building temperature zone control.

Ahern's innovative solutions with prefabrication and BIM were very beneficial throughout the job. Their team led the charge on BIM modeling, and worked with the entire construction team to coordinate and familiarize everyone with this design.

Jason Krueger

Project Manager

Oscar J. Boldt Construction

Ahern was instrumental in bringing this project in on time and to budget for our company... We could not be more pleased with the way Ahern managed this project for our company.

Steve Peterson


Mid-States Aluminum

Ahern’s performance and knowledge of complex mechanical systems is exceptional.

Kyle Loest

Project Manager

J.H. Findorff & Son Inc.

Ahern's team was professional, prompt, and brought a great deal of expertise to our project! Their team was also very valuable in assisting us with our LEED certification. Their knowledge in the certification process was very helpful.

Paul Smedberg

Project Manager

C.D. Smith Construction

Ahern’s hard working and knowledgeable team was able to develop, among other contributions, cost-saving ideas that were extremely helpful.

Jim Lau

HVAC Designer

Thelen Engineering