Energy efficient, cost savings, occupant comfort

25 February

According to FlowCon International in Denmark, a leading global PICV Valve manufacturer, the U.S. Energy Information Administration published in 2017 that 76% of the world’s energy is consumed in buildings, 20% of the world’s electricity is used to pump fluids around and that high-performance HVAC systems account for over 40% of the energy used in commercial buildings. Considering that 90% of the whole life cost of a pump is energy related, reducing pump activity remains an important strategy to achieve significant energy savings.

When legislation for conservation of fuel and power called for initially 20% and now 30% reduction in C02 emissions, research into heating and indoor climate control was aimed at identifying technologies that offer the greatest potential for improvement and savings.

Historically, actuated control valves have controlled the water flow to terminal units in the UK. In unbalanced hydronic systems, heat transfer equipment closest to the pump was potentially too hot as a result of overflows, whereas heat transfer equipment furthest away from the pump experienced underflows, which affects the ability to deliver the design temperature. The challenge was to balance the system minimising the overflows and underflows. Traditional control valves allow for overflow and underflow to coils which means excess water is pumped to compensate for inaccuracies. As a result, actuators in these traditional valves had to cycle more often to compensate for pressure changes in the system, decreasing the actuator lifetime and increasing pump activity and energy use.

Static/Proportional Balancing Principle: The fow rate is dependent on the pressure change across the valve (Q=A*√ΔP). The flow rate and ΔP increase. The Orifice area is fixed.

The Pressure Independent Control Valve (PICV Valve) in variable flow systems has been widely credited for providing pump savings of up to 35% by delivering system stability. On top of that, further cost saving can be realised through a simplified system design using the PICV Valve for optimal pump control. This can result in energy, emissions and cost savings of 10-40%.
The Pressure Independent Control Valve was designed to replace the conventional 2-way control valve, balancing valve and system differential pressure control valves, so that pressure changes in system would no longer affect the flow. The PICV Valve is typically installed in buildings controlling the flow, temperature and pressure in heating and cooling systems. To achieve the most efficient and optimal results in a system, the exact required amount of chilled or heated water must be delivered to the heating and cooling terminal units.

Dynamic/Automatic Balancing Principle: The flow rate is independent of the pressure change across the valve (Q=A*ΔP). The flow rate is constant, ΔP increases. The Orifice area decreases.

In a nutshell, the Pressure Independent Control Valve offers many benefits compared to the traditional control valve:

1. Easy selection and automatic limitation of the flow to design set point

a. Free from overflow, independent of pressure changes
b. Energy savings

2. Fewer valves required

a. Reduction in system head loss – less restriction/resistance
b. Reduction in pump size
c. Energy savings

3. Lower installation cost, less installation time, simplified commissioning process

a. Setting and ΔP flow verification process, no proportional balancing
b. Commissioning time reduced to by 75%

4. Retrofitting and multi-phased works without rebalancing – valves will adjust automatically to maintain the set flow rate

5. No installation restrictions – can be installed anywhere in the line without affecting its performance

6. Lower building running cost through system stability and reduced pump energy consumption

7. Precise temperature control resulting in an improved indoor climate for occupants

If you want to know more about the benefits of the PICV Valve, its’ applications and variable flow system design, please get in touch with us for a free CPD presentation.

FAQs

What are pressure independent control valves in HVAC systems?

Pressure independent control valves in HVAC ensure consistent flow to terminal units despite system pressure changes, improving efficiency and comfort.

How do energy-efficient valves reduce energy consumption?

Energy-efficient valves like PICVs minimise unnecessary pumping and maintain ideal flow rates, which significantly reduces power use.

What is a pressure independent balancing and control valve?

A pressure independent balancing and control valve maintains flow rate, temperature, and pressure automatically—combining the roles of multiple valves in one.

What is the PICV valve working principle?

The PICV valve working principle involves automatic modulation of the internal orifice to keep flow stable, regardless of differential pressure.

What are the benefits of energy saving valves in commercial buildings?

Energy saving valves reduce pump workload, improve balancing, lower operating costs, and enhance indoor climate control.

Can pressure independent control valves replace traditional balancing systems?

Yes, these energy-efficient valve systems eliminate the need for static balancing and differential pressure valves, simplifying the system design.

What is the role of independent control systems limited by pressure?

Independent control systems limited by pressure provide better control over HVAC performance and energy usage, especially in variable flow setups.

Are PICVs effective in retrofit projects?

Absolutely. PICVs automatically adjust flow without the need for manual rebalancing—ideal for phased or retrofit projects.

How much can PICVs save on energy bills?

Studies show PICVs can reduce pump energy use by up to 35% and contribute to total energy savings of 10–40%.

Do PICVs require frequent maintenance?

No. These energy-efficient valves are low maintenance due to their self-adjusting design and reliable components.