Lewis Kwit in Building Operations on August 2, 2019
Heat balancing at the Normandy, a 235-unit cooperative on Riverside Drive, was a big issue. Some of the apartment lines were really cold because they faced the Hudson River, and others were overheated because they were inside facing the courtyard, or facing south. Fixing this imbalance was a priority for the new board president, and he already had bids ranging from $500,000 to $750,000 when we came on the scene.
Before spending a lot of money to fix a problem, it pays to do some sleuthing and testing. This board did just that, first surveying the residents to find out who was too hot, too cold, or just right. Ninety-two percent of the residents responded, which gave real information to work with.
With this knowledge, we suggested a simple kind of energy management system: motorized valves. The Normandy has lots of different mains and risers, so putting a valve at the bottom of the riser, then coupling that with sensors in representative apartments, could help to balance the system. The board president didn’t want to commit funds to this fix unless it worked, so we decided to test it on two apartment lines. If we were successful in making the hot apartments comfortable, and the cold units warmer, then everyone could be confident that this was the way to go.
Everyone except the contractor we hired to do the work, that is. He said that the heat could be reduced in the apartments that were too hot but that the motorized valves couldn’t make more heat go up into the apartments that were cold. “There’s no extra heat that we are able to tap in order to be able to send it up there,” he said. “We would have to control the entire building to have extra heat. It is what it is.”
Then Hurricane Sandy hit. Everything shut down, so there was lots of time to ponder the balancing problem. I knew we could make the hot apartments cooler, but I didn’t know how to make the cool apartments warmer. That’s when it became clear that we had to go back to Energy Conservation 101.
When you go back to energy basics, there are two things that need to be checked: windows and radiators. The Normandy is a landmarked building, and half of the apartments had changed their windows and had good, new windows, while the other half had the original steel casement windows, and they were really leaking. So we identified two things to check: the number of apartments that had window or through-the-wall air-conditioners and the state of the radiators. I assigned a staff member to accompany building staff as they surveyed each apartment in the “too cold” line. We wanted to make sure there was a radiator in each room, that it worked, and that it was not blocked. When the inspection was finished, my staff prepared a report on the conditions in each apartment.
We learned that the air-conditioners weren’t covered and that apartments facing the Hudson River received lots of winter wind and drafts. Working closely with the super, we had the building staff work in the two lines to weatherstrip all the original windows and put thermal air-conditioner covers on all units that were left in the walls and the windows over the winter.
People were going up to the board president saying, “Hey, this worked!” Cold and hot units alike reported greater comfort. Once the basics were in place, the heat could be adjusted. Subsequently, the whole building was divided into four zones, so steam could be sent where it was needed. The total cost for this solution was about $150,000, significantly less than the original bids. Meanwhile, building staff continued to weatherstrip original windows and install air-conditioner covers throughout the cooperative.
One of the takeaways is that nobody does this kind of project alone. Two board presidents, back to back, were involved and stayed involved with this program. And you need a great super and building staff to follow through with diligence.
Lewis Kwit is president of the consultancy Energy Investment Systems.