F20-19.1 Central City Opera House Heating/Ventilation System

Acknowledgements

Project Advisor:
Antonie (Tony) Vandenberge

Technical Advisors:
Professor Chris Coulston PhD.,
Professor Paulo Tabares-Velasco PhD.,
John Toussaint

Donations Made by: None

Video

Elevator Pitch

The Central City Opera House is the cultural heart of Central City, yet it can only operate in the summer due to the bitter cold. The student design team was tasked with designing a heating system to allow operation year-round. While the opera house is old, construction has been ongoing, and each region have very different properties. The Team identified three different areas, and each received a unique heating solution.

The auditorium requires a huge amount of heat and will be serviced by two boilers and 4 air handlers. These along with supporting equipment such as pumps and reservoirs will be located in the only available space: the crawlspace beneath the seating area. To avoid the complications inherent in bringing the entire crawlspace up to code, a smaller equipment room will be constructed within it. The workshop requires only one boiler, but has no space for equipment, so its systems will share the crawlspace equipment room. Routing ducting to the workshop is infeasible, so instead, hot water will be pumped to suspended hydronic heaters on the workshop ceiling. The cast house is already outfitted with a roof top air conditioning unit and supporting ducting. However, the unit itself has exceeded the end of its useful life, so the Team has recommended a replacement that will add heating functionality.

To increase the effectiveness of the heating system, an insulation package was recommended which included lightweight spray foam insulation for the auditorium attic and workshop ceiling, replacement doors for all but the main entrance, and a large insulating curtain for the workshop service door. The main entrance and windows are historically relevant, so artisan door restoration and custom window inserts will be required.

Design Approach

Design Solution

The Team explored multiple options for equipment, locations, and heating methods. After exploring all other options and many conversations with the client, the Team determined that the only suitable place to locate the equipment was underneath the seating area in the crawlspace. This meant that heating the auditorium was comparatively easy, By routing forced air strategically into the auditorium through the floor and tapping into an existing rear duct to allow for recirculation, the auditorium zone can be handled by a self-contained hydro-air system.

The heart of the first system would be a set of two Laars MagnaTherm HTD 2500 water heaters, which would generate the required heat. For the warm water to deliver heat to the auditorium, it needs to be passed through a heat exchanger, which will transfer the heat from water to air. To force the hot water through the heat exchanger, a pair of pumps are required. The Team recommended Gould Water Technology’s e-MPA group pump to fill the role. To Force air across the heat exchanger and cycle air through the auditorium, air handlers are required. The team determined four Carrier 39MN25W air handling units would be up to the task. To remove reliance on the opera house’s inconsistent water supply and keep the system functioning, a 500-gallon reservoir will be added to the system. The Team suggested an Ace Roto-Mold VT0500-46B vertical storage tank for this purpose.

With the auditorium handled, the workshop was next up on the agenda. While the Team originally wanted to create a similar system to handle this zone, the clients strongly preferred for the workshop to lose none of its current work/storage space, as that would inhibit their ability to conduct two simultaneous productions. To address this preference, the Team considered creating an external structure to house the equipment, but after conducting research and speaking with technical advisors, the technical, legal, and financial difficulties associated with this option made it prohibitive. On advice from technical advisors, the Team perused a hydronic heating strategy. Hydronic heaters are smaller than air handlers, and don’t use ducting. Rather they consist almost entirely of a heat exchanger and a simple fan. This smaller form factor allows them to be suspended from the workshop ceiling. Of course, this still left the problem of where to put the heat source. The only remaining option for equipment storage was the crawlspace under the seating area, so the Team decided to pipe the hot water from there to the workshop through a series of wall penetrations. The basics of this system are the same as the previous one, but some specifics are different. To generate the heat, another Laars MagnaTherm HTD 2500 water heater was chosen. To transport the warm water, two of Gould Water Technology’s 3656/3756 S group pumps were selected. To distribute the required heat, 8 Dayton 1EBC3 Horizontal hydronic heating units will be necessary. Like the previous system a reservoir will be necessary, and the Team again recommends an Ace Roto-Mold VT0500-46B vertical storage tank.

This just leaves the cast house. Earlier in the project’s development, the Team had been exploring things like adding a heat exchanger to the existing roof top air conditioning unit or tapping into the existing ventilation for a forced air solution, but none of the Teams plans had really stuck. The Team hit upon a spot of good luck fairly recently though. Upon review of a report that was conducted over the summer by an outside engineering firm, Marx | Okubo Associates Inc., it was found that the existing roof top air conditioning unit was nearing the end of its useful life and required replacement anyway. This allowed the Team to search for and recommend a new comprehensive unit that could handle both air conditioning and heat through the simple addition of a gas line. The Team recommended a roof top unit with a direct exchange (DX) cooling coil and heat exchange (HEX) – RT-PRC077E-EN – 7.5 Ton system to handle this task.

In addition to the selected equipment and location, other challenges presented themselves. In order to improve the effectiveness of the heating solution to acceptable levels, the Team needed to address the huge amount of heat leaking out from the opera house through leaks and uninsulated surfaces. The first recommendation the team made here was to insulate the ceilings with polyurethane spray foam insulation; this was chosen because of its effectiveness and light weight. The single pane windows proved more difficult to tackle, as historic property guidelines made replacement impossible. The Team found a solution in “Indows” window inserts; The company has a reputation for helping to sure up old buildings such as Alcatraz Prison, making them a perfect fit. The doors were another issue. While most were not historically significant and could be replaced without issue, the front doors, as per historic guidelines, will need to be restore/replaced by an artist to ensure cultural integrity isn’t lost. The Team’s research led them to recommend Meticulous Restoration in Englewood to handle this.

Finally, an additional challenge presented itself in storing the equipment in the crawlspace. As-is, the space cannot legally house equipment, as it is an enclosed space. To rectify this, the Team has outlined the basics of a new room that will be constructed within the crawlspace, complete with its own legal egress.

Though it took considerable trial and error to reach this point, the Team believes this unique solution will allow the Central City Opera House to attain its goal of year-round operation.

Next Steps

In the event that the project is continued by another group of students, there are some further items that can be expanded upon, especially by civil engineering students or mechanical engineering students with a focus on HVAC. The Teams experience was enough to provide the energy specifications and to select equipment that met those needs but was not able to optimize the actual orientation of the equipment and the layout of both the piping and ducting. While the equipment has been oriented within the room in the crawlspace and there are tentative routes presented in the construction drawings, HVAC students would be able to optimize the layout and the supply lines to the equipment. The drawings present are sufficient to start the bidding process, although further expert layout is advisable.

Meet the Team