Wi-Fi ACU Control for HVAC Energy Savings. April 25, 2017

Transcription

1 Wi-Fi ACU Control for HVAC Energy Savings April 25, 2017

2 Introduction Schools are seeking energy and cost savings projects that are: Cost Effective Good Payback/ROI/SIR Inexpensive (Relatively) Simple to Implement Do not trigger code

3 Typical California School Energy Usage HVAC accounts for almost 50% of energy use

4 Introduction LED Lighting: Energy efficient (>100LPW) Cost effective: Good Payback/ROI/SIR Inexpensive (Relatively) Simple to implement Does not trigger code HVAC Upgrades: Relatively simple to implement Triggers code (including T-24) Expensive (equipment + labor + logistics) Average energy savings Existing SEER to new 14 SEER Not cost effective Average to poor Payback/ROI/SIR Low hours of operation High first cost Existing equipment has long useful life. May not be ready for upgrade

5 Current HVAC Unit Control Current Controls are Stand-Alone: Localized scheduling Schedules entered at each thermostat No way of knowing if schedules are altered T-stats operate w/ last entered schedule Localized temperature setpoints Thermostats can be set for any setpoints No Lockouts set Heating can run during summer No control of HVAC compressor staging Y1 & Y2 are often set backwards 2 nd stage cooling operates first

6 Solution Wi-Fi Enabled Thermostats Control Existing HVAC Equipment: Enables Building/Campus Dashboard Dynamically and accurately manage Operating Schedule Allow for local override of set time durations (1 hour) Sweep off ALL systems Control temperature setpoints Lockout heating/cooling at specific times Example: Lockout heating during Summer Manage HVAC compressor staging Most package units have two (2) stages of cooling Stages can be same size, but often one is larger Start the smaller stage 1 st, operate 2 nd stage only as needed Highly cost effective

7 Wi-Fi Thermostats Interface: Provides a Building & HVAC Dashboard/Overview

8 Wi-Fi Thermostats - Dashboards Quick word about Dashboards Wi-Fi thermostats create a Mesh-Network Any Dashboard can be programmed to See the mesh and interface with it through APIs Allows for Open control Strongly recommend against Proprietary systems Application program interface (API): Set of routines, protocols, and tools for building software applications. API dictates how software components are to integrate/interact. APIs are used to programming graphical user interface (GUI) to connect to hardware and other software.

9 Wi-Fi Thermostats - Dashboards Quick word about Dashboards Contd. The School can provide a dedicated, isolated (behind firewall) IP address for communication OR An independent network can be provided for the Dashboard Independent com network is inexpensive (~$20/month) Systems are Cloud Based, so no local hardware to maintain Allow for Multiple Usernames with varying levels of access Level 1: Can see only Local School/Class T-stats Level 2: Can see Campus wide Level 3: Can see and modify Local School/Class setpoints/schedules Level 4: Can see and modify Campus wide setpoints/schedules All credentialed users have unique logins to allow tracking and eliminate loss of access when personnel depart

10 Wi-Fi Thermostats Contd Scheduling: Allows for Overall & Specific Scheduling Critical for Energy Savings Turn HVAC Off!

11 Wi-Fi Thermostats Scheduling: Allows for Overall Control of Setpoints Critical for Energy Savings Manage how HVAC Operates!

12 Wi-Fi Thermostats Strategies: Allows for Peak Demand management Determine Peak Demand threshold and manage HVAC to remain below the threshold. Stagger/stage operation of HVAC units. Utilize Fan Only w/out cooling for 15 minute intervals Slightly raise setpoints to minimize calls for cooling and compressor runtime Critical for Cost Savings Manage when HVAC Operates!

13 Wi-Fi Thermostats - Installation Installation: Simple wire-to-wire connection Ensure install quality is high and consistent Utilize qualified Company & personnel Use Vanity/Wall Plate covers to avoid holes in walls from existing T-stats Experienced to understand wiring for various types of HVAC units, split systems, packaged units, through wall units, etc. Supervision by Journeyman electrician to certify install on all units

14 Cost Effectiveness Example: Southern California Climate Zone: Electricity Savings: 400-kWh/ton/year Typical 4 ton unit savings: 1,600 kwh/year (Usage of 8-9,000kWh/yr) Utility cost: $0.18/kWh to $0.22/kWh Electricity cost savings: $320/year (@ $0.20/kWh) Wi-Fi Thermostat Implementation Costs: Materials: Thermostat, wall plate: $275 Labor: $175 Interface: $75 Overhead: $75 Total: $600 (Can be between $500 - $800) Payback: 1.9 years (Not including any natural gas savings) Highly cost effective 20 to 40% HVAC energy savings

15 Case Study Prentice Day School 32 Rooftop AC units 8 Through Wall/Bard AC units w/ Stand-alone thermostats No programming on T-stats Excessive AC unit operation

16 Solution Wi-Fi Thermostats w/ Controls Maximize off hours while maintaining comfort Schedule & control AC units Easy Installation Simple thermostat interface Excellent energy savings Excellent HVAC energy reduction Utility incentives available (varies)

17 Results Prentice Day School, Santa Ana Main Admin Building Four Classroom Bldgs. Science Bldg. Six Portables 32 rooftop heat pump units 8 through wall AC units Electricity use: 206,000 kwh/yr Electricity cost: $43,200/yr Savings of 48,300 kwh/yr (1,510 kwh/unit) Elec Cost Savings of $10,100/yr 23.4% Overall Energy Reduction Utility incentive of $6, % Funded through On-Bill Financing Client is very pleased. Achieving energy savings Teachers & Staff like familar/simple interface

18 Case Study Prentice Day School, Santa Ana The Prentice School Lassen Drive North Tustin, CA Reference: Jared Robison Network IT Manager Cell:

19 Contact Chikezie Nzewi Director of Energy Engineering EMCOR Mesa Cell:

20 Q & A

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