David Braley Athletic Centre, McMaster University
McMaster University — Hamilton, Ontario
David Braley Athletic Centre
Replacing conventional control and balancing valves with Griswold Controls pressure independent control valves to reduce energy consumption and deliver exceptional system performance.
Project Overview
The Challenge
The David Braley Athletic Centre, located on the campus of McMaster University in Hamilton, Ontario, is one of the largest fitness centres at any Canadian university. The athletic complex includes a double gymnasium, indoor 200-meter track, four squash courts, multipurpose studios for karate, yoga, dance and tai chi, and one of the only in-ground hydrotherapy pools in the country.
The building was originally specified with conventional control and balancing valves. Kildonan Energy Products, the local Griswold Controls sales representative, working with University personnel and the construction/design team, identified an opportunity to significantly improve system performance and energy efficiency by switching the air handler chilled water valves to Griswold Controls pressure independent control valves.
With 11 valves serving a peak chilled water flow of approximately 300 gpm, and coils selected for a design ΔT of 10° C (18° F), the system needed to deliver reliable, efficient performance across a wide variety of occupancy and weather conditions.
The Solution
The design team replaced the originally specified conventional valves with (10) Griswold Controls PIC‑V® and (1) MVP™ pressure independent control valves. The building connects to the central plant’s chilled water supply and return lines, and contains variable speed chilled water booster pumps that only run if the mains’ differential cannot satisfy the building.
- Self-balancing operation Valves respond only to load changes, not system pressure fluctuations — eliminating the need for separate balancing valves.
- High ΔT performance Coils deliver their full design heat transfer potential, maximising chiller plant efficiency.
- Booster pump savings With consistently low chilled water flow requirements, the booster pumps rarely, if ever, need to run.
- Simplified design One valve replaces the conventional control valve and balancing valve pair at each coil.
The Results
Performance of the pressure independent control valves has been excellent. ΔT across the athletic centre has been as high as 17° C (31° F) — nearly double the design ΔT — with all systems meeting set point.
“One cool morning in September of ’07, the building was running with 24 gpm of chilled water — less than 10% of the design flow. With the exceptional control provided by the Griswold Controls valves, chilled water flow requirements are very low and the booster pumps rarely, if ever, need to run.”
— Facility Services, McMaster UniversityMcMaster University’s facility services personnel, under the supervision of Chief Operating Engineer Joe Emberson, are diligently dedicated to achieving ideal comfort performance combined with reduced energy consumption from the campus chilled water system. Griswold Controls’ pressure independent valves are proving to be an invaluable resource toward achieving those objectives.
Questions about this application? Contact info@GriswoldControls.com or 949.559.6000
Pressure Independent Control Valves
Griswold Controls’ MVP™ and PIC‑V® are Pressure Independent Control Valves. Pressure independent valves dramatically reduce the energy costs, capital expenses, maintenance costs, performance issues, and capacity limitations associated with typical HVAC system pressure fluctuations. They are designed to replace the conventional 2-way control valve and balancing valve pair installed at heating and cooling coils in buildings.
To obtain the most efficient and optimal results in a system, only the necessary amount — no more and no less — of chilled or heated water must be delivered to the heating and cooling coils at all times. This saves energy, increases available plant capacity, minimizes capital expenses, and simplifies system design and control.
Pressure independent valves stabilize flow. With stable flows, the designed heat transfer is maintained. The result is energy savings because less flow is required to achieve the same heat transfer.
Every year billions of dollars are wasted due to the weaknesses in HVAC heating and cooling systems. If systems do not consistently operate at their designed temperature differential, energy waste occurs and money is needlessly thrown away. This unnecessary expense can be eliminated by using Griswold Controls’ pressure independent valves.
When conventional 2-way valves are used to control the flow of water through coils, various actions — such as adjusting a valve or changing the pump speed — affect pressure in the distribution system. These actions in turn affect the flow through a two-way valve even if the load does not change. The thermostat responds and the valve modulates to bring the flow back to what is required. Until the flow is corrected, the coil operates at an off-design point and will over – or under – condition the space.
With a pressure independent valve, set point deviation will not happen. The valve responds only to a signal from a thermostat indicating the load has changed. By responding only to the change in load, the pressure independent valve is self–balancing — it delivers the proper amount of flow regardless of the state of other components in the system. The entire HVAC system is always in a state of constant flow balance.
Griswold Controls’ MVP and PIC‑V pressure independent control valves ensure that all HVAC systems achieve steady flow and high ΔT at all loads, guaranteeing stable temperature control and better heat transfer — resulting in lower energy costs and lower flow requirements.
MVP™ — Features & Benefits
MVP pressure independent control valves maintain the required flow rate regardless of pressure fluctuations.
- Pressure independent control Provides balancing at any point below and including the maximum flow rate, eliminating hot and cold spots in a building.
- Reduces energy required Increases chiller efficiency by 15–20% and increases ΔT across coils, heating and cooling more space with less equipment and energy.
- Flow stability regardless of pressure No change in flow regardless of pressure fluctuations up or downstream — requires less work for the actuator and increases actuator life.
- Multifunction modulating 2-way control Combines differential pressure control with modulating control into one compact valve housing.
- Reduces valve and actuator hunting Compensates for pressure changes in the system, increases occupant comfort, and extends both actuator and seat life.
- Low torque Reduces actuator size needed, allowing for use of a less expensive actuator.
PIC‑V® — Features & Benefits
PIC‑V & SpaceSaver PIC‑V combine a balancing valve & control valve into one, maintaining flow control regardless of pressure fluctuations.
- Pressure independent control Provides balancing at any point below and including the maximum flow rate, eliminating hot and cold spots in a building.
- Flow stability & efficiency No change in flow regardless of pressure fluctuations — heat and cool more space with less equipment & energy, increasing actuator life.
- Controls flow exactly Eliminates all overflow or underflow at coils.
- Low torque Reduces actuator size needed, allowing for a less expensive actuator.
- Universal mounting plate Offers compatibility with most manufacturers’ actuators.
- Next generation triple seals & field-repairable stems Provide resistance to chemical treatments and temperature fluctuations, and allow field servicing without removing the valve.
Have a question about this or another Griswold Controls Case Study?
Fill out the form below and someone from Griswold Controls will get back to you shortly.