December 19, 2023
The idea is simple; take the efficiencies of HVAC component equipment and make them available in a package to the commercial Multizone market utilizing 94%+ AFUE furnaces, individual economizers, and high efficiency condensing units to match BTUH requirements. Arrange all of these components in this modular package so you can easily replace existing Multizone units, and make sure the end user is comfortable. Custom Mechanical Equipment’s team did just that when they designed and built the first PMZ on the customer’s roof a true build and then design job. That was in 1988, and the economics of the idea are still undeniable as our track record proves.
Replacement of equipment that was 70 to 80% efficient when installed with equipment that is highly efficient and never reheats mechanically cooled air will save money. In addition, direct drive variable speed motors allow supply air control at a fraction of the cost of constant speed belt drive motors. Maintenance is performed inside the Penthouse out of the elements, and warranties are unmatched: 10-year heat exchanger, five-year compressor and one year on all other components. But all of these benefits would mean nothing without the personal service that is the hallmark of every PMZ we build. The service starts with a no charge site visit to establish existing conditions. We then review the mechanical plans and current conditions to allow for proper sizing and have a field technician on site for the set and start-up, as well as follow up after the project is complete. Add that kind of service to the shortest manufacturing lead times and units that are available in fifteen colors, and we truly have the most unique rooftop unit available.
There have been many changes since the first PMZ (which is still operating efficiently today) was put into service in 1988. The weight of the unit has decreased while the efficiencies have increased. The internal control is no longer electro-mechanical. Today all units are DDC controlled with an open protocol controller. Heating sources available now include natural gas, LP, electric, hot water and dual fuel with gas and heat pumps. Cooling sources include DX and chilled water. Geo-thermal capability is unmatched in our rooftop unit because of our modular design. These are additional tools on our design belt that enhance our PMZ. We give our customers the appropriate product for their application and needs.
The modular concept of the PMZ has fostered many unique designs, both in our rooftop PMZ and our indoor version. Up-flow, down-flow, horizontal, and side discharge, as well as adding ERVs or a separate unit in the return air compartment to pre-treat return or outside air in extreme conditions are just a few of the non-standard designs. The end result will be unique, and the concept constant–energy efficiency.
