The Carlisle Mosquito Online

Friday, November 19, 2004


How did Town Hall get an "inadequate" HVAC system?

The Carlisle Town Hall was built in 1997. (Photo by Midge Eliassen)
At the upcoming Special Town Meeting on December 6 voters will be asked to approve a revamp of the Town Hall heating and cooling (HVAC) system at a cost of about $150,000. It is hoped this will finally put to rest a problem that has defied solution for the past seven years. But how did the town get into this predicament? Did those involved in Town Hall planning and construction do their job? Were costs cut too close to the bone?

Problems from the start

In 1997 the new Carlisle Town Hall opened for business with much fanfare. After years of failed attempts to bring employees under one roof, Carlisle had finally built a Town Hall citizens could be proud of. A volunteer town building committee made up of well-qualified architects, engineers, and contractors had spent many months in planning and overseeing the construction of the new edifice. Town employees who had long endured cramped, isolated, and uncomfortable conditions (crowded into part of what was supposed to be the town library or in trailers parked throughout town) welcomed their new home with gratitude and relief.

Within weeks, however, the glow of moving into bright new quarters began to tarnish as problems with the HVAC system emerged. Employees in one part of the building worked in ski parkas while in another area they sweated. According to Town Administrator Madonna McKenzie, temperatures as low as 54 degrees were recorded, and Town Hall had to be closed on one occasion due to the unavailability of heat.

Over many years of evaluations and quick fixes, a harsh reality emerged; there was no magic answer that would not cost considerable money. Reluctantly, the town last spring put aside $25,000 to develop a bid package for overhauling the system. The bids will be closed November 30.

Major cost-cutting needed

An obvious suspect in the HVAC case is the cost-cutting that took place before construction of the building. According to Ed Sonn, who headed the Town Hall Building Committee, initial bids for construction ran $300,000 to $400,000 beyond the $1.6 million estimate. "This is not a fancy building, but there was a lot of ledge. Blasting is very expensive." In addition, the architect had designated a computer-controlled HVAC system using hydronics (boilers) that was a substantial expense at $380,000. Attempting to stay within budget, the committee looked for places to cut, and the HVAC system was an obvious target.

In a fax dated November 8, 1995, Michael Spence, principal of TMP Consulting Engineers, Inc., responded to a request by Greg Sullivan of Donham & Sweeney, Inc., architects on the project, to itemize areas where cost savings could be realized. In order to bring the HVAC cost from $380,000 to $210,000, Spence suggested a "radical redesign." The changes included elimination of the hydronic (boiler) system in favor of overhead air; downgrading the control system, and reducing the number of air handlers from five to two. Total cost savings were estimated to be between $170,000 and $195,500. A letter from Donham & Sweeney dated December 21, 1995 further reduced the cost of the HVAC by combining "the air-handling units and five remote chillers into one roof top HVAC unit" for a total savings of $228,000.

In his fax, Spence warns that ,"The elimination of the hydronic system will obviously impact the over-all comfort of the building and life expectancy of the air-handling units. The change from DDC to electric controls will reduce the ease of control of the system and require more maintenance. . . Heating from below by radiation also is a more comfortable system. Heating by air overhead may cause some drafts . . . Despite the disadvantages listed, it is still recommended to pursue this system because major cuts need to be realized."

Sonn points out that ,"In those days, $1.6 million was a lot of money for this town" and the committee had to ask, "Are we going to come up with something Town Meeting will find acceptable?" He adds, "We did our best to come in close to budget," and to meet their goal, the top-of-the-line system would have to go. But, he adds, "At no point were we told by the engineer or architect the system we were installing would be inadequate, which it is."

The engineer responds

Reached at his office in Boston on Tuesday, Spence seemed unaware of the problems the system he designed had caused. Though he has only hazy recall of the specific project, he says, "We didn't recommend the cheaper system, but we were responding to 'What can you give us for 'y' dollars?'" He notes that these kinds of cuts are not unusual. "It happens in about 20 to 25% of municipal jobs. On a scale of good/better/best, we'd like to give them the 'best' system, but sometimes they can only afford 'better,' and sometimes only 'good.' "

Spence continues, "I'm sure we made them aware the system would be less reliable and less efficient, and they would have more complaints with fewer zones." He says typically complaints arise from "human nature" and differing preferences regarding temperature. "If you get eight people in an area, one will have a sweater on and one will be in a short-sleeved shirt." In addition, the configured system doesn't respond well to short-term temperature fluctuations. According to Spence, the best solution for office buildings is multiple zones, whereas Town Hall has only one.

Spence disputes that the system is inadequate. "How often is it maintained and balanced?" he asks. He says rebalancing of the system may need to be done twice a year to adjust for differences between heating and air conditioning. "All-air systems are funky. They need more maintenance to tweak them." (Note Spence's 11/95 fax warned of higher maintenance requirements.)

1998 assessment

In 1998, Building Engineering Resources, Inc. provided an assessment of the system and confirmed the difficulty of balancing it. On July 21 they reported, "The system can not (sic) supply warmer or cooler air based upon exposure or based upon individual zone demand. The temperature control can only be accomplished by a delicate air balance to supply the minimum air flow to handle the space while reducing that air flow as the space conditions change. This type of balance will tend to either over or under condition a space as the room conditions vary greatly beyond the design condition." They concluded, "The method of system control and the inability to have individual zone temperature control are the reason (sic) for the problems being reported. . . The usage of the facility can have an occupied Office Area and a fully loaded Meeting Room. The system will provide a single temperature air to each space. . . . The rooftop unit can supply only one temperature." The report recommended baseboard heaters, additional controls, and moving furniture. A rebalancing was done but other recommendations weren't implemented due to space limitations.

New System

The new system will consist of a boiler, new piping, multiple control units and heating coils. The control units will allow different temperatures to be set in different parts of the building. The gas unit on the roof will be used only for air conditioning and as back-up if the boiler fails.

McKenzie notes this HVAC system is essentially the one originally proposed in 1995. Recently two contracting companies reviewed the current system and independently recommended the same solution. "I feel confident this will finally be the answer," sighs McKenzie.

Questions and perspectives

So was choosing a cheaper system at a cost savings of over $200,000 a bad decision? To put it in perspective, it helps to remember the Carlisle tax base in that era before the influx of mini-mansions was less than half what it is today. Two hundred thousand dollars was real money, and weighed against such intangibles as "less comfortable and "draftier," it's easy to see why the committee was swayed. Even the higher maintenance cost is easy to defend — it would take considerable maintenance to approach the $200,000 savings.

But should we continue to live with it? All evidence indicates Carlisle's system can never be a source of warmth and comfort to Town Hall employees. While Spence points out there are other municipalities with low-end systems similar to ours, we must ask, "Is this the way we want our employees to work?"

In the end, technology has been Carlisle's friend, reducing the cost of installing a decent system, which is now probably less than what it would have cost originally. So rather than think of spending $150,000, perhaps we should think of it as $50,000 saved — not counting the cost of time, consultants, lost productivity, and seven years of discomfort.

2004 The Carlisle Mosquito