Tight space requirements paired with a need for a very close cross over temperature between the boiler and water temperatures led to SWEP BPHEs being the ideal heating solution chosen over competing technologies.
Four academic wings of a mid-sized, urban community college in the northeast (covering approx. 700,000 square feet) needed to replace their existing high temp/high pressure boiler plant that had provided heating to the facility for over 30 years and SWEP BPHEs (brazed plate heat exchangers) were the perfect heat transfer source for the new low temp/low pressure system that was desired. This application was for commercial heating of the campus. In addition to the Central Plant, the BPHEs installed on this job are required to heat multiple buildings on campus.
SWEP’s dealer Mechanical Marketing knew that SWEP BPHEs would be an advantageous solution for this project and were an integral part in working with us to help educate involved parties to ensure our heat exchangers made the spec for this. Mechanical Marketing is a Manufacturer's Representative of Engineered Products in the Commercial, Institutional, and Industrial HVAC and Plumbing marketplace. Their areas of expertise are commercial hydronic heating, radiant space heating, and domestic hot water production. They serve the Design Markets of Mechanical & Plumbing Engineers along with the mechanical contractors in the Southern New England territory.
One of the main reasons that SWEP BPHEs were chosen was because of the ability to provide a 2F cross over temperature between the boiler temperature and the heating system water temperature. The importance here was due to the fact that condensing source equipment (boilers) were to be installed to elevate the entire Seasonal Efficiency of the system. If at different times of the heating season the heating system can be satisfied with SWT below 130°F, the condensing boiler efficiency is elevated significantly.
Furthermore, SWEP was the basis of the design because their BPHEs are AHRI certified. In fact, SWEP is the first company to provide Brazed Plate Heat Exchangers certified by the Air-Conditioning, Heating, and Refrigeration Institute (AHRI). Testing performed by AHRI contracted laboratories verify that product performance is according to specified ratings in data sheets and selection software. This offers additional security when selecting BPHEs for your HVAC installations. SWEP was actually just awarded the AHRI Annual Performance award for the 3rd year in a row, so our customers can trust that they will be provided with the right BPHE models for all of their applications.
The engineers wanted to be certain they could depend on the close cross over performance. By allowing temperatures just above the heating system requirements, along with boiler efficiency, the system transmission loss was also greatly reduced. For this project, a total of close to (20) B649 models were installed. SWEP’s B649 model is the largest BPHE model on the market today, and is ideal for district heating and cooling networks, HVAC, and industrial projects that need an efficient, compact BPHE with close temperature approaches at high operating pressures. This install called for the B649 model in various plate counts. The order was given to SWEP after Engineer Approval of our submission in July 2019. The new heating system was online before September 2020 (the start of the heating season in CT), and the date of Substantial Completion of the project was October 20, 2020.
Another huge consideration leading to the choice of BPHEs was that the heat exchangers selected here had to be installed and housed in the small existing mechanical rooms. Therefore, space consideration was a giant factor which led to the more compact SWEP BPHEs being the favored solution for not only the floor footprint space, but the overhead space as well in all five mechanical rooms. (See the photos of each mechanical system.) Also, by using SWEP’s CIP (Cleaning-in-Place) system, complete servicing of the heat exchangers is available if ever needed and can be done in an extremely small space without having to take an exchanger out for rebuild or repair as you have to in PHE (gasketed plate heat exchanger) applications. A SWEP heat exchanger is cleaned by circulating a cleaning liquid through it and disassembly is not required. You can even equip your BPHE with customized CIP ports to make it even easier. Additionally, our calculation software SSP (SWEP Software Package) offers a Pressure Drop tool, which can be used to determine when an installed BPHE needs cleaning by comparing the measured pressure drop data with the expected performance of a clean BPHE. This provides added cost savings in maintenance, which is just one more advantage BPHEs offer over the older, larger heat exchanger technologies.
One of the B649 models installed with the CIP (Cleaning-in-Place) ports
Legacy systems like this are typically designed with PHE and Shell & Tube (S&T) designs and engineering firms have always favored these older technologies simply because this is all they have known. BPHEs are a somewhat of a new concept to them in terms of larger HEX models, so educating these firms on the optimized solutions BPHEs can provide in these types of applications is an absolute must in order to promote BPHEs as the premier design choice in these systems. In the lead up to winning this project, SWEP and Mechanical Marketing gave a presentation to the consulting engineering firm involved which showcased examples around the world where our heat exchangers operate and were able to convince them BPHEs can indeed be used for larger sized applications. The customer was amazed with the size/compactness of the BPHE and how clean the installation looked. After the installation, the college administration and local fire inspectors expressed their satisfaction with the compact footprint of the HX, as well as the overall aesthetic appeal of the installation. Ferguson, a diversified specialty contractor supplying fully integrated electrical and mechanical systems for new and renovated construction projects, were also a huge part of installing the BPHEs on campus.
BPHEs can provide superior life cycle cost for district energy systems in a compact, reliable package, whether it is district heating or district cooling like in this case. They offer efficient heating and cooling solutions for homes, offices, schools, and hospitals while still maintaining a low carbon footprint. In the past, traditional solutions like S&T or PHE have been used, but these take up a lot of space and require regular maintenance. SWEP has pioneered the development of the gasket-free BPHE which has several clear advantages. The BPHE maximizes the most efficient transfer of energy and the lifecycle cost over a period of 15-20 years can often be halved compared with gasket-plate solutions. In a nutshell, Gasket-free BPHEs mean minimal maintenance, less cost on spare parts and reduced downtime for cleaning.
Size of a Plate & Frame HEX vs. our smaller, compact BPHE
Designed to make the most efficient use of energy, material, and space, BPHE technology is quickly winning ground around the world in multiple applications, with SWEP at the forefront of developments. We will continue to strive to ‘challenge efficiency’ around the globe!