In the commercial rooftop market, equipment replacement selections are often driven by the contractor, said Hank Gellert, Bryant commercial marketing manager.

“The buying decision is often coming from the contractor,” he said, “and he or she typically is not responsible for the building energy costs.”

However, contractors can do their customer a real service by explaining which replacement unit offers the best value - looking at first cost as well as operating costs.

In too many cases, the building owner may solicit multiple bids and thus higher-efficiency systems are “value-engineered out of the bid, and replaced by dollar/ton unit costs” in order to be the low bidder for the project. It’s a numbers game where operational costs and benefits are not really considered.

In order to move it from installed costs to life cycle costs, and to judge the merits of repairing heat pump rooftop units rather than replacing them, contractors need to state the pros and cons to the real decision makers, the owners.


“The entire industry is transitioning to more and more efficient equipment,” Gellert pointed out.

Commercial efficiency standards are being legislated in areas where the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) Standard 90.1, the efficiency standard for multistory nonresidential buildings, has been adopted into code.

Change is also being driven by the green movement at state and federal levels. “The LEED concept has been specified on many federal buildings throughout the country.


In between larger commercial buildings and government buildings, is a market of smaller, privately owned commercial buildings that could really benefit from an upgrade of its HVAC system, if someone would propose it to the building owner.

If the owner is bidding out the mechanical work based on the lowest prices, the trend to higher-efficiency equipment doesn’t happen. This is a missed sell-up opportunity for the contractor as well as a missed opportunity for the person who pays the energy bills.

“Often, in our business, it comes down to the bottom dollar,” Gellert said. “When you’re dealing with an open bid, with loose specifications, it may just come down to dollars/ton.” In this case, he said, the owner may pay less for the mechanical system up front, but the occupants pay more for its operation. There are multiple software tools available to the contractor to demonstrate a simple payback analysis to the end user/customer. Demonstrating this information in a professional manner with documented facts is a way for the contractor to differentiate their business and build loyalty with the customer.

Serviceability of the system is something else to be considered. “Many end users don’t take this into account,” Gellert said. “A good example is changing filters. You see a lot of systems that might have their filters changed once a year. If the rooftop is more serviceable and easier to maintain, there’s a payback.”

New rooftops often have factory-installed options available to make the units easier to maintain, clean, service, etc., thus facilitating higher operational efficiencies. This is another example of criteria that should be considered in the repair versus replace model.


“Often times the contractor will know immediately that money spent on repairing an existing unit is a bad idea,” Gellert said. “It’s putting good money to bad if the unit is 25-30 years old - it has clearly outlived its lifetime.”

In some situations, a contractor may suggest a quick repair to get the system up and running and strongly recommend that the customer consider a replacement in the near future. This is especially true, he said, if the repair is relatively minor.

However, at the same time the servicing contractor should be doing a full inspection of the unit to determine the future reliability and expense to repair. “Planned replacement is a lot easier to accept and budget than the immediate replacement. The old unit can be replaced at a time when it is more convenient for the building occupants.”

Replacing a rooftop unit offers a variety of equipment options on the newer units, Gellert said. The Bryant DuraPac™ Plus 14 SEER rooftop, for example, offers an economizer and this results in additional energy savings in many regions of the country. “The whole goal is to reduce energy consumption,” Gellert said. Savings from the use of economizers can be as high as 40 percent in some climates, he said.

To further promote energy savings, today’s packaged rooftop units offer CO2 sensors for IAQ control. This allows you to bring in the proper amount of fresh air as needed - versus always bringing in a fixed amount based upon theoretical building occupancy. Fresh outside air often requires energy to cool, dehumidify, and heat so if large amounts are not needed, don’t bring it in.

Other options available on packaged rooftops include smoke detectors, convenience outlets, electrical disconnects, etc., all intended to either meet local codes or make the unit easier to service and maintain. These items need to be brought to the attention of the person making the purchasing decision as they often will aid in lower installation and maintenance costs of the new system.


If lowest cost is the owner’s main concern, contractors should look to present information that supports more efficient building operation - lowest life-cycle cost, to get the discussion on value rather than lowest dollars.

Part of the discussion should center on occupant comfort and productivity. Existing equipment that is unreliable creates complaints and down time for the occupants. It can also damage the reputation of the servicing contractor as he or she often takes the blame for a faulty HVAC system when, in fact, the old units just flat out need to be replaced. Additionally, when presented with the energy-savings data along with the warranty coverage, the case to replace versus repair can lead to successful business opportunities for the contractor.

Publication date:05/28/2007