💡 LUMENS vs LUX — What’s the Difference? When designing a lighting system, we often hear the terms Lumens and Lux. But they measure two different things. 🔆 Lumens (lm) → The total amount of visible light produced by a light source. 💡 Lux (lx) → The amount of light falling on a specific surface or working area. 📐 Basic relationship: 1 Lux = 1 Lumen / 1 m² For example, the same 1000-lumen LED can provide: ➡️ 100 lux when the light is distributed over 10 m² ➡️ 50 lux when the light is distributed over 20 m² This is why lux level is more important when evaluating whether a space has sufficient illumination for its intended use. 🏢 In MEP / Lighting Design: 1️⃣ Determine the required lux level 2️⃣ Calculate the required lumens 3️⃣ Select suitable LED fixtures 4️⃣ Determine the number and arrangement of fixtures 5️⃣ Verify the achieved illumination level 📌 Remember: Lumens = How much light the source produces. Lux = How much light reaches the surface. A simple concept, but an impo...
REFRIGERANT FLOW CONTROLS IN HVACR SYSTEMS Understanding Metering Devices, Applications, Advantages, and System Protection Every vapor-compression HVACR system requires a method of controlling refrigerant flow between the high-pressure and low-pressure sides of the system. This component is commonly called a: Refrigerant control Metering device Expansion device Refrigerant flow-control device The metering device performs two essential functions: It creates the pressure drop that allows high-pressure liquid refrigerant to enter the lower-pressure evaporator. It regulates the quantity of refrigerant entering the evaporator so that the coil can absorb heat without starving, flooding, or returning excessive liquid refrigerant to the compressor. Historically, six major types of refrigerant controls have been associated with HVACR system design: Thermostatic Expansion Valve Capillary Tube Automatic Expansion Valve High-Pressure-Side Float Valve Low-Pressure-Side Float Valve Electronic ...