The Logistics of Buying and Installing a Backup Generator

What's the first step for a condo or co-op board? Commission a feasibility study. Dave Brijlall, energy team leader for Rand Engineering & Architecture, estimates a good study can run between $7,000 and $10,000. According to engineers who do this type of work in New York City, generators for a condo or co-op are about the size of a suburban parking space, and roughly six to seven feet tall. In an emergency, they would probably fuel common area lighting, water pumps (to keep toilets flushing), elevators and perhaps heating inside apartments. Installation can cost $200,000 to $300,000. "It's a big number for an occasional event," says Eric Cowley, president of Cowley Engineering.

Location, Location, Location

Moreover, there are serious logistical issues about where to place a generator. If you're in a flood zone, think twice about putting it in the basement. Even if you can locate it elsewhere, it does no good if the rest of your electrical systems are in a flood-prone basement.

If your building is not vulnerable to flooding, the basement is a possible location if there's enough space. The roof is a possibility, but that can require structural improvements. Rooftop generators also have to be tied into electrical systems down on lower floors, adding to bottom-line costs.

Another complication comes from buildings with Con Edison steam heat, carried in pipes running through the basement. "They usually don't have the infrastructure needed for venting, and creating one can be very expensive, so that sometimes kills the deal," says Doug Lane, owner of Lane Engineering Consulting. Venting is required when installing a generator to make sure that toxic fumes don't enter living spaces.

Buildings with boilers that provide steam heat are often good candidates because their chimneys are designed and built larger than needed, he adds. In those cases, the chimneys still must be inspected and evaluated.

Catching the Flue

In addition, if the generator runs on gas, the chimney flue may need to be lined to prevent fires and toxic gas leaks. This makes installing one a costly proposition. If it runs on diesel or oil, a place to store fuel is required. "Noise cancellation" enclosures will also be needed to comply with city noise codes, adding to the expense.

According to City code, a hard-wired emergency generator must be able to keep certain building systems running: emergency lighting; at least one elevator in each building or section; emergency communications equipment, if it exists; and under certain conditions, the pumps that operate fire sprinklers, says Christopher Hartnett, principal at Lawless & Mangione.

Some buildings opt for more features to be wired to the generator, but wiring even just the essential functions can require extensive electrical work. While the code requires only emergency lighting, it is almost always cheaper and easier to wire all common areas to the generator, Hartnett says. In the event of a blackout, a transfer switch senses that power is going down and signals the generator to start up. Once power starts flowing back from the utility, the generator shuts down.

It's a Gas, Gas, Gas?

Boards also have to weigh whether the generator will run on natural gas or No. 2 oil/diesel, which is a combination of almost identical fuels. Previously, New York City code allowed only residential multifamily buildings the option to go with gas, says Keenan Nolan, a sales engineer for generator distributor Huntington Power Equipment. That changed this year with the new Local Law 111 of 2013, which allows any building to use natural gas for emergency generators. While part of the concern about gas is the possibility of a service interruption, the opposite has proved true, according to Nolan. "During Sandy, our diesel customers couldn't get fuel but our natural gas customers did just fine," he says.

Hartnett, however, generally recommends a diesel generator since the fuel is stored onsite. Also, gas-fired generators usually cost about 50 percent more than their diesel counterparts. Sometimes if a building is already using gas to power its boiler, it can make sense to use a gas-fired generator, but this option can also require a booster pump to upgrade the gas service line from the street, he adds.

For more, see our Site Map or join our Archive >>