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A brief-overview of the highlights of the 2nd kuwait HVAC&R Conference, a confluence of ideas to improve HVAC system efficiency and implement best practices in construction.
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HVAC&R BEST PRACTICES FOR SUSTAINABILITY Presented by Mr. Sagar Kulkarni LEED AP, WELL AP, PQP, CEM, CEA Managing Director, CEC
Need for Best Practices • Energy-efficiency is the cornerstone of sustainability • In the current scenario, unchecked use of energy is leading to a rapid increase in global temperature • According to the Key World Energy Statistics Report, 2017 published by the IEA, Kuwait has one of the highest per capita rates of electricity consumption – 14951 kWh/capita/annum • As a member of the COP21 Agreement, substantial efforts need to be made to reduce energy consumption and meet the requirements for reduction of carbon emissions Consistent Engineering Consultants. www.consistentconsultants.com
Overview of Energy Consumption • According to the Annual Statistics Report published by DEWA, the Residential sector was responsible for about 74% of the total energy consumed in Dubai, in 2016 • 79% of the total electricity consumed in residential applications was for cooling and air conditioning systems Annual energy end-use distribution for a typical villa Source: KAPSARC analysis Consistent Engineering Consultants. www.consistentconsultants.com
Electricity Consumption by HVAC Systems in Middle East • Nearly 58% of the total energy is consumed by HVAC systems. • However, the adverse climatic conditions of the Middle East makes use of HVAC systems imperative, especially in summer • The peak power demand in summer in the region is nearly thrice the peak power demand in the other months • Implementation of HVAC Best Practices contributes directly to energy conservation and hence, improved sustainability Consistent Engineering Consultants. www.consistentconsultants.com
METHODOLOGIES TO REDUCE HVAC CONSUMPTION Implementing the Sustainability Principle Consistent Engineering Consultants. www.consistentconsultants.com
1. Ensure Detailed Engineering (Avoid Thumb Rules) • Ensure Detailed Engineering Calculations and use of the appropriate software. • Thumb rules are a yardstick for measurement but should not be considered absolute • Selection of correct unit for application i.e. DX, VRF, Package, Chillers, Evaporative Cooling etc. Consistent Engineering Consultants. www.consistentconsultants.com
2. Appropriate Orientation of Glazing in Buildings (REDUCE) • Ensure glazing between East and North West • Orientation of glazing in buildings in a way to obtain maximum natural light and ventilation • No additional cost • Energy savings up to 15% Consistent Engineering Consultants. www.consistentconsultants.com
3. Use of Air Curtains to Seal Building Envelope (REDUCE) • Air curtains reduce thermal exchange through an opening in the building envelope • Lack of transmission of ambient heat to the interior of the building reduces load on the air-conditioning system Consistent Engineering Consultants. www.consistentconsultants.com
Consider the example of power consumption in a mall with and without the use of an air curtain: • Door dimensions: 3m x 3m • Average no. of people visiting the Mall = 3000 per day • Case 1: No Air curtain Total Energy Consumed = Net energy Consumption + Energy Consumed due to Heat Infiltration = 307 kWh/day • Case 2: With Air Curtain Total Energy Consumed = 120 kWh/day Consistent Engineering Consultants. www.consistentconsultants.com
4. Appropriate Selection of Material (REDUCE) • Selection of appropriate material to optimize the heat transfer co-efficient reduces the load on HVAC system Consistent Engineering Consultants. www.consistentconsultants.com
5. Use of FAHU with Heat Recovery System (RECYCLE) • Case 1: Conventional FAHU with cooling coil only. • Case 2: FAHU with dual heat recovery wheels. • Difference between Power Input = 197.5 – 159.3 = 38.2 kW • Total Savings in Annual Power Consumption = 267,705.6 kWh • Total Savings = 120,000 AED; Payback period – 6 months • Total savings = 40,155.84 KD; Payback Period – 1.5 yrs Consistent Engineering Consultants. www.consistentconsultants.com
6. Directing the Extracted Air on Condensing Units (REUSE) • Directing the extracted air over condensing units for improved condenser performance. • As the ambient is cooled down in surrounding area of condenser; the condensing temperature is brought down. Consistent Engineering Consultants. www.consistentconsultants.com
7. Use of Inverter-Based Compressor • Inverter-based compressors have a small variation band • Power consumption is reduced due to lack of multiple start stops Consistent Engineering Consultants. www.consistentconsultants.com
8. Use of Equipment Having High COP/EER • Better the COP, lesser the energy wasted • Use of equipment having a high energy rating can reduce nearly 7-8% of the total energy consumption Consistent Engineering Consultants. www.consistentconsultants.com
9. Use of VFD for Pumps and Fans • Use of variable frequency drives can reduce energy losses by nearly 40% • Soft-start and soft-stop motors help to avoid surge in voltage for AC motors, improving service life Consistent Engineering Consultants. www.consistentconsultants.com
10. Precise Installation • Leak proof construction • Proper sealing of ducts and pipes during • construction • Replace temporary filters after pre-commissioning • Enough flushing of air during commissioning to • remove VOC (Volatile organic compounds) • Commissioning by qualified agencies • Use of leak detection systems Consistent Engineering Consultants. www.consistentconsultants.com
11. Regular Maintenance • Air Filter – Clean Filters to remove dirt buildup • Refrigerant - Make sure there is a appropriate Refrigerant pressure is maintained. • Air vents - Make sure there is nothing blocking the air flow • Coil Cleaning - Remove dirt from coils on condenser and evaporator • Drafts and Leaks – Have central air ducts cleaned yearly for proper air flow • Insulate pipes, caulking windows and doors • Moving parts – Lubricating moving parts to work efficiently and easily Consistent Engineering Consultants. www.consistentconsultants.com
Residential Project in Dubai Consistent Engineering Consultants. www.consistentconsultants.com
Residential Project in Dubai Project Overview • Total area: 125, 090 sq. m. • Function: Mixed Use – Commercial & Residential • No. of Buildings: 4 • Structural layout: Tower 01 and Tower 04 (3B+G+28), Tower 02 and Tower 03 (3B+G+20) • Key Goals: • Implement Green Building Requirements in Design • Maximize energy efficiency Consistent Engineering Consultants. www.consistentconsultants.com
Residential Project: Measures Implemented for Optimizing Energy Efficiency • 75% of roof area insulated by material having solar reflective index ≥ 78 • Orientation of 50% of the building as 150 degrees northwest from east for maximum natural lighting and ventilation • Centralized Fresh Air Handling Units with Duel Heat Recovery Wheels used to treat fresh air provided to all areas. • Apartments designed for optimal thermal and acoustic comfort as per regulations • Use of thermal bridges to reduce flow of external heat into the building • Airlocked lobbies with air curtains at entrances and exits to prevent loss of air • Use of centrifugal water-cooled chillers with high EER • VFD driven Secondary chilled water pumps. • Use of Treated Waste Water for make up of the Cooling Tower. • VFD Fans for Cooling Tower Consistent Engineering Consultants. www.consistentconsultants.com
Impact on Energy Conservation • 14% energy savings with respect to green building standards, with proposed building design • Approximate energy savings with respect to normal buildings = 30% Consistent Engineering Consultants. www.consistentconsultants.com
Sustainable Buildings Consistent Engineering Consultants. www.consistentconsultants.com
The Future of Sustainable Buildings • Use of Occupancy Sensors • Use of high Surface Reflective Index materials • Use of Thermal Bridge • Use of evaporative cooling in areas having low Wet Bulb Temperature • Use of Condensate Drain water • Proper insulation for Ducting & Piping (BS 5422 ) • Proper Installation (No Duct Leakages, proper Flushing, Commissioning by experts etc) • Proper Maintenance (Engineered maintenance team, monitoring regular performance etc.) Consistent Engineering Consultants. www.consistentconsultants.com
THANK YOU Move Away from Verification and Complianceto Performance Based Specifications #Dubai Building Index#Kuwait Building Index www.consistentconsultants.com