Building Efficiency: Parity's HVAC Optimization Reduces Energy Use

Reducing energy and emissions is a top priority, but for buildings with HVAC equipment, it’s important to understand the energy needed to operate it. You want to make sure the energy being used is actually working to meet, rather than exceed, demand. Robert Post, a senior sales engineer at the HVAC optimization company Parity, recently worked with a co-op in Harlem to maximize the efficiency of the building’s heating system as well as its central air conditioning system. 

Driving Blind

The problem for the co-op was that the building’s staff was unable to see how the equipment was running. Apartments have fan coil units for their heating and cooling needs, but the resident manager had very little information about the pumps, cooling tower and fan motor operations or the building’s temperature settings. “It was like driving a car with no dashboard,” Post says. “The building had pieces of equipment on the rooftop in different mechanical rooms, and they had some controls, but there was no centralized online dashboard for the resident manager and the building staff to see everything.” Parity was able to create a centralized system where the building manager could easily see all the set points for the equipment. 

An example of this is the temperature of water circulating in the hot or chilled water system. A small change in the temperature of the water indicates that the apartments are not calling for as much heating or cooling at that moment. 

Generating Data 

In order to generate the data needed, Parity installed various controls and sensors on the equipment. “The building owns the equipment and it’s typically off-the-shelf equipment like VFDs, which are variable frequency drives that allow the motors to change speeds, as well as heating controllers, sensors and other equipment,” Post says. The equipment Parity installed in Harlem also included sensors in hallways and on pipes. 

Parity then takes the monitoring of the equipment a step further by remotely controlling all those HVAC components in real time. “This makes sure that supply always meets demand and we eliminate waste from the system,” Post says. This can involve slowing down the motor speeds to accommodate a lower demand for either heating or cooling, depending on the season. “This way you’re not oversupplying the loop when people aren’t needing heating or cooling,” Post says. This is done using algorithms — as well as the input of engineers — to remotely control and make adjustments to all the equipment up to every five minutes. As a result, the company can guarantee savings for the building. The cost of Parity’s installations ranges from $50,000 to $250,000 depending on the building. “A lot of that cost can be covered by Con Edison, through their incentive programs,” Post says. The installation in Harlem took a couple of weeks. The biggest challenge was getting Con Edison to do the inspection and pre-inspection, Post says: “It takes a long time, and we typically get 30% to sometimes 50% of the up-front installation covered by Con Ed, and the challenge is proving it to them and having them come out and justify what we’re doing.” 

Partners in Efficiency

The co-op has a five-year contract with Parity for its services. “It’s really a partnership with the building staff and our team,” Post says. “So not only are we controlling things remotely, but we’re also boots-on-the-ground support.” This means that if there’s ever an issue with any of the equipment, an engineer will be dispatched to work with the building staff. There is also a commissioning period after the installation is complete when the programming of equipment takes place. “We really lean on resident managers and their expertise on their buildings to get those set points adjusted so that they aren’t getting new heating and cooling complaints and we’re really increasing the comfort of the building,” Post says. 

Parity can also help the building diagnose problems. “We send alerts and alarms to the building staff if we see something abnormal,” he adds. Another added benefit of the installation is how the optimization of the equipment extends the longevity of the mechanical system. “If you’re not running equipment at 100% and you’re modorating it, it’s going to last longer,” Post says.