Because of his background, tenant comfort is his utmost concern. And zoning is the only way to achieve premiere comfort in his buildings, contends DiCicco. “The more zoning, the better zoning, the more comfort. That’s it in a nutshell.”

Zoned to the gills

Six Carrier 50FP Weathermaker™ III single-packaged rooftop units combined with perimeter fan-powered boxes and interior vav boxes make up the hvac system.

But DiCicco didn’t stop there. He decided to add zoning to the building as well. “Zoning is very important. One of the number-one complaints in any office building is it’s too hot or too cold, so the better you address that through individual zoning, the better chance you have that those tenants will be comfortable.”

Two rooftop units service the top floor, due to rooftop load, while each of the other floors are serviced by a single unit, and there is one zone per 1,000 sq ft per floor. The zones work independently of one another and are controlled by a ddc system.

All the corner offices are in individual zones, as well as any boardrooms and conference rooms. Different exposures, such as southwest or northeast, have different sets of zones and different configurations of controls as well.

The system was designed with two goals in mind: comfort and efficiency, the zones for comfort and the equipment choices for efficiency. DiCicco knew that more money up-front would mean money saved in lower operating costs in the end.

The single-package rooftop units were chosen for their high-efficiency motors; factory-installed, product-integrated controls; and indoor air quality features. The units are linked using a three-wire communication bus, which allowed for minimal field installation, maximizing on factory labor. Duct-mounted CO₂ sensors ensure that the right amount of outside air is brought in without the added costs of overventilation.

In this building, tenants have total flexibility in controlling the temperature within their zones through individual thermostats.

DiCicco understands that it will never be possible to satisfy every tenant all the time, simply because of the human element. Each person is different, and while one may be comfortable in a particular zone, the other may be more sensitive to heat or cold.

As the owner and contractor on the project, DiCicco notes that he had the advantage, because he knew exactly the type of system he wanted.

“I’ve been on the other side of the table where the right amount of zoning wasn’t originally designed. I knew the problems, I heard the complaints. So when it came down to making my selection of equipment and zoning, I knew we needed to install the proper amount of zoning, because that’s the only way we’re going to maintain a comfortable temperature level.”

Costs more but worth it

“However, I feel it’s money well spent, because of the flexibility you have with the tenant comfort. It’s something you really need to do in today’s office environment.”

While there may be a payback involved with zoning, DiCicco says that’s not the reason why he chose it for this building. All he was looking for was improving tenant comfort and reducing the number of complaints.

In addition, he wants to retain his tenants, and by keeping them comfortable, he has a better chance of having them renew their leases year after year.

DiCicco believes that more building owners would opt for zoning if it were presented to them during the initial design phases of the building.

“If building owners knew what they were paying for and saw the benefits of what they were paying for, I don’t see why they wouldn’t want to pay for it. But possibly these issues are not brought to their attention.”

Not that it’s the fault of the contractor in situations like these, notes DiCicco. Engineers are often the ones responsible for mechanical system design in larger office buildings, and it is up to them to bring it to the owner’s attention.

“When a contractor installs a job, he’s installing the job based on what is engineered — what’s on the drawings, what they bid on. We rarely have communication with the owner. The engineer was the one who had that dialogue, and the zoning question has to take place during those conversations.”

Of course, it’s always the building owner who has the final say about the type of system installed. If the budget is tight and there’s no money for zoning, the best engineer in the world won’t be able to convince the owner to add it.

However, if the owner says that comfort is important, the engineer should take the opportunity to explore zoning. Many building owners may not even be aware that it’s an option, so it can’t hurt to bring it up anyway.

That doesn’t mean the contractor doesn’t have a role in the zoning system, though. DiCicco advises contractors to really look at the drawings and speak up if they feel that additional zoning could make for a more comfortable environment.

“If they see something that isn’t quite right, or they think that additional zones would be helpful, they should call it to someone’s attention. At least do that and give someone the option of addressing it,” says DiCicco.

As for his building, DiCicco says there were absolutely no problems, and everything went smoothly. “The building’s functioning very well, the tenants are quite happy, and it turned out to be a very good project.”

It was such a good project that DiCicco is constructing another building and doing things exactly the same way. “We won’t be changing anything,” he says.