From Steam to Green: How A Beekman Hill Co-op Made the Leap

Around 1500 buildings in New York City use Con Ed steam for heating and cooling, and many are considering moving to electricity to reduce their carbon emissions. If your building has a distribution system that uses the same pipes for heating and cooling, like the Beekman Hill co-op discussed in this episode, there are steps to take and timing issues to consider. Habitat Magazine's Carol Ott speaks to Controlled Combustion president Michael Bendjouya about what those are.

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Transcript

Carol Ott: Welcome to Problem Solved, a conversation about challenges facing New York's Co-op and condo board directors. I'm Carol Ott of Habitat Magazine and with me today is Michael Bendjouya, president of Controlled Combustion. It's a very big deal to change your building's heat and cooling system, particularly if you are considering using electricity.

Michael, your firm has recently completed an electrification project at a large co-op in Beekman Hill in Manhattan. Can you tell us what kind of system the co-op had in place and what were the changes your company did to electrify it? 

Michael Bendjouya: Yes. To begin with, the building was serviced by ConEd city steam, where ConEd has a pipe going into the building that provides steam at high pressure and the pressure gets reduced and they use that steam , in this building's case to provide the energy for heating and also to provide the energy for cooling with a steam absorption chiller system. 

Carol Ott: So this building had, unlike some co-ops, had central air for cooling and for heating. Is that correct? 

Michael Bendjouya: Yes. It had a central air a combination system, both heating and cooling, where either chilled water was sent through the fan coil units or heated water, depending on the time of the year. 

Carol Ott: Describe to me what was on the roof. 

Michael Bendjouya: Typically air conditioning systems like this have a cooling tower on the roof. They have a machine in the basement that gets fed the steam, liquefies a chemical and pumps that chemical up to the roof where it exhausts the heat through the cooling tower.

And there's an exchange in the basement where the water gets chilled and pumped through the building. 

Carol Ott: And they had ConEd steam to power this? 

Michael Bendjouya: Yes. They use steam to, to liquefy the crystals of the chemical. There are other buildings that have boilers that produce steam to do that and still use a similar system.

And that would probably be a candidate for doing a job like this. 

Carol Ott: So the co-op wanted, and maybe they had to do something to their system, maybe it needed fixing. I assume they didn't just say, let's make the switch. 

Michael Bendjouya: Steam is probably the most expensive method to provide heating and cooling or either one for a building reason being just the nature of the city steam system.

After the steam condenses in the building, it turns to water. The water gets chilled because it's too hot to go down the drain, but ultimately goes down the drain. Whereas a system that recaptures that condensate and can reheat it and make steam again, there's a tremendous benefit and not losing all that energy going down the drain.

Carol Ott: So was this building motivated to change their system because of their operating costs? Because of New York's local L 97, their system needed some kind of fixing and this made sense to change at the same time, or do you know? 

Michael Bendjouya: It's all of the above really. Other buildings where it doesn't lend itself to this type of total electrification are putting in electric chillers on the roof and eliminating the cooling tower and absorption system.

Carol Ott: What physically had to be put in place so they could get rid of ConEd steam? 

Michael Bendjouya: They needed a device that would provide heat for the winter and cooling for the summer. They had an engineer develop plans for installing heat pumps on the roof that are cooled by air, the surrounding air around them, and heat pumps in the basement that use water as a source for cooling so that the units in the basement provide domestic hot water only and the units on the roof provide heating and cooling.

Carol Ott: There must be pipes running from the basement to the roof. 

Michael Bendjouya: There are and because timing is an issue in these types of jobs. There's a window when you can do the work that's required to provide air conditioning when it's cold out.

And then ultimately. May 1st, April 15th, May 15th in that window, most buildings wanna see their system online to be assured that they can provide cooling for the summertime. So during this last winter, we ran new risers up the building. I. And the original thought was we were going to replace the existing risers and use that same area within the walls to put the new risers.

But if we did that, we wouldn't have the time needed to get the air conditioning online. So we found an area that allowed us in the staircase to core drill from the roof down to the basement and install new rises in there. And then we we boxed them in to make it like part of the wall.

Carol Ott: Did you have to go into people's apartment or this was just done? These risers were run. 

Michael Bendjouya: We attacked it a different way. And because the risers alone were replaced, the individual piping to each apartment in each room in the apartments is all reused. And it's connected to the main risers that we replaced.

Carol Ott: I see. So you could electrify the building without having to go into each apartment. 

Michael Bendjouya: In this particularly case, yes. 

Carol Ott: And do you know if each apartment could control, like before, I guess its own heat and cooling? 

Michael Bendjouya: Yeah. They have fans that blow over coils that have the heated or cooled water in it.

And the thermostat that's connected to those fans is what? Gives them individual control in those rooms. 

Carol Ott: So each apartment, do they get a bill, an electric bill from ConEd, or is the building sub-metered? 

Michael Bendjouya: This particular electrification is not a sub-metered one. It's one for the whole building.

Carol Ott: So does that mean that the co-ops will still get a utility bill, which I guess now is an electric bill for the whole building? 

Michael Bendjouya: Yes. 

Carol Ott: I see. Okay. 

Michael Bendjouya: Yes. And part of what we're doing is installing a new electric service up to the roof to handle the units up there. We've brought in more service from the street with Con Ed's electrical division.

And we've wired a distribution between them. 

Carol Ott: And how complicated or lengthy a process was it to get the additional electric service from ConEd? 

Michael Bendjouya: They were pretty fast. There was only I would say 60 days to get their ruling. 

Carol Ott: So there was electricity, or there was enough electrical power or whatever you would call it in the street already. 

Michael Bendjouya: In this particular case not enough. They had to add. 

Carol Ott: And by adding, does that mean that the street is dug up? 

Michael Bendjouya: Yeah. They did an excavation for it. 

Carol Ott: And that was only a 60 day process. 

Michael Bendjouya: 60 days was to get the approval for it. And I don't know the amount of time it took to, to go to construction, but I do know that it's been installed at this point.

Carol Ott: I see. And so for other co-ops contemplating this, who would be a good candidate to replace either fossil fuel or steam with electric heat pumps on the roof or this kind of a system? 

Michael Bendjouya: I would say any building that has a distribution system that uses the same pipes for heating and cooling is a good candidate for this.

Carol Ott: And in older buildings where it's not centrally cooled, but it is centrally heated, obviously with a radiator, would they be a candidate even though it's only using half the system that this building has? 

Michael Bendjouya: No, I don't believe so. 

Carol Ott: Okay. Okay. For other buildings who might be contemplating this, what would be your sort of 1, 2, 3 pieces of advice for them?

Michael Bendjouya: This is the first electrification job that I know about and we're performing it. But throughout the years, we've converted buildings to gas. There are always more efficient boilers that are being built, and if the building accepts the fact that they do have to burn gas, there are many things that can be done with their existing equipment. We have also installed electric boilers for domestic water applications where there's a high zone and a low zone and a high zone up in the building. They generally need steam year round just to make domestic water, and we've replaced that.

We're just finishing one up on 89th Street where we put in a Sussman electric boiler with a heat exchanger on the, I don't know, 40th floor, something like that. And again, the challenge was bringing the power up there. This particular job, there wasn't enough power in the building, but we still needed to get new switch gear and run new service up to that unit.

Carol Ott: And let me ask you for that building up there. Was it relatively fast to get the electric power from ConEd? 

Michael Bendjouya: The power was within the building. So we didn't need ConEd for that. We did need filing with ConEd approval from ConEd, but we didn't need construction from ConEd. 

Carol Ott: For the Beekman Hill project, what was the expense to do the electrification project or the range? 

Michael Bendjouya: I would say they're in the $3 million area. 

Carol Ott: I see. I see. And do you have any sense of what they hope to save in terms of their operating expenses using electricity? 

Michael Bendjouya: I know that their goal was to stop emissions and I don't think it was driven solely by, the operating expense of maintaining heat and cooling in the building. So I'm not privy to those numbers. No. 

Carol Ott: But by changing what was on the roof, I presume some of their operating expense for maintaining that chiller they got rid of. 

Michael Bendjouya: Yeah. Definitely. 

Carol Ott: And one more thing you had mentioned it was challenging in terms of timing.

For another building who's planning such a project, is there a certain time of year when you would advise somebody to start or just to be cognizant of these timing issues? 

Michael Bendjouya: You need to be cognizant because you can start the job really at any point during the year. It's just that you have to work on the reverse utility, if that's the word.

In other words, when the building needs heat, you have to work on the cooling side and then switch over and do the cooling when the do the heat, when the building needs the cooling. 

Carol Ott: I see. And one finally, because you didn't have to go into apartments, I presume the residents of this building didn't really feel disruption while you were doing your work, or did they?

And if so, what was it? 

Michael Bendjouya: There wasn't any. 

Carol Ott: And that's a beautiful thing. 

Michael Bendjouya: For sure. 

Carol Ott: Thank you very much, Michael. This has been really informative. 

Michael Bendjouya: Thank you. Nice talking to you.