Tim Sisson - Trane HVAC OVERVIEW

HVAC OVERVIEW

HVAC Systems

System Types

Acoustics

Controls

Modernization … more than one

• Down to the Studs

– Opportunity for new “System” Type

• Renovation

– Possible opportunity for new “System” Type

• IT + Systems Upgrades

– Information Technology Upgrade

– Lighting and Controls

HVAC System Types

• CHPS Design Manual

– System Types

– Evaluation Matrix

System Types

• Unitary or Packaged Equipment

– Single Zone Constant Volume

– Single Zone VAV**

– Variable Air Volume

System Types

Central Systems

• Hydronic Heating and Cooling

– 4 Pipe

– 2 Pipe (Back to the Future)

• Centralized Heat Pumps

– Water Source & Ground Source

• Decentralization of Complex Components

– Refrigeration Compressors

• Centralization of Reliable Components

Modernization: System Change

• Typically…existing central system is replaced

with individual packaged unitary equipment.

• Why?

– 1st _Cost

– Perceived reliability

Single Zone Constant Volume

• Most typical unit change out “upgrade”

• Adapter curb allows for intermixing of mfg.

• Standard connections?

• 2-Stage Compressor

– Stage 1 = 67% Capacity – Stage 2 = 100% Capacity

• System operates in

low stage in part load

conditions

• Enhanced

temperature control

Packaged AC - Hi-Efficiency Fan Motors

• E

lectronically

C

ommutated

M

otors (ECMTM, X13*)

• Permanent magnet, brushless, DC Motor

• Constant torque – pressure independent fan

operation

• Wide operating

range

• Soft-start

capability

Air Conditioning Units – Energy Efficiency

Unit Options - Reduce Maintenance Cost

Option Downflow Horizontal Hinged Access Panels Yes Yes Hail Guards Yes Yes Circuit Breakers Yes Yes Disconnects Yes Yes Phase Monitor Yes Yes Convenience Outlet Yes Yes Smoke Detectors Yes Yes Hot Gas Reheat* Yes* Yes* Factory installed economizer Yes Yes

Phase Monitor Hinged Access Doors

Hail Protection

Disconnect Switch 115VAC Outlet

RTU -

Supply Fan Energy Savings

San Diego 33% _24% 67% 64% 0% 20% 40% 60% 80% 100% 13 EER 15 EER Fresno 27% _20% 73% 69% 0% 20% 40% 60% 80% 100% 13 EER 15 EER Livermore 39% _29% 61% 58% 0% 20% 40% 60% 80% 100% 13 EER 15 EER Compressor/Condenser Supply Fan

* Modeled using TRACETM _{Load Design Software}

15 SEER units have ECM Supply Fan Motors

Displacement Ventilation - Concept

•Energy Savings

•Improved Indoor Air Quality

•Acoustics Performance

Displacement Ventilation - Practice

Classroom Diffusers

DV Rooftop Packaged HVAC Unit

DV - Modernizations

• Barriers

– Ceiling Height - 9Ft. Minimum

– Diffuser location

Central Systems

2 Pipe Systems

Legacy System Limitations

• Entire System on for one classroom use • No simultaneous heating & cooling

• Switchover lag

Modernization

• Technology Upgrades

– Air Cooled Chillers with Scroll Compressors – Integrated Pumping Packages

– Central Equipment Turndown Capabilities – Direct Digital Controls

– Enhanced Boiler Performance – Improved Building Envelope – Rapid Switchover

Increased Flexibility Reduce Cost • Low + High Head Pumps • Variable Speed Pumps • Buffer Tank

Air Cooled Chillers

-

Industry Overview

OLD

Component Improvements

Brazed Plate Evaporator Electronic Expansion Valve “Low Noise” Condenser Fans Scroll Compressors Digital Controls

Special Applications

Partial Heat Recovery

• Up to 140F leaving water temperature

• Roughly 20% of heat recovered from cooling load • Pre-heat for pre-heat of swimming pools, etc. **

• Sanitary water: (need separate heat exchanger for

potable water)

• Fan control for better heat recovery at part load and reduced ambient temperatures

Acoustics - Impact on School Design

• Isolating the classroom

• Controlling room absorption

• Selecting HVAC equipment

HVAC Systems in Schools

In-room l unit ventilators* l fan-coils* l PTACs l mini-splits *cabinet style Central l chillers with central air handlers l large rooftop units Near-room l unit ventilators* l fan-coils* l water-source heat pumps* l single-zone rooftop units *concealed

Near-room

HVAC system

Near-room

HVAC system

supply airborne casing radiated + return airborne source receiver

Near-room

HVAC system

Near-room

HVAC system

source receiver supply airborne return

Near-room HVAC system

Near-room HVAC system

source receiver supply airborne supply airborne return airborne return airborne casing radiated casing radiated

Acoustics

• ANSI/ASA S12.60 limits can be met using

– Standard equipment from major HVAC companies – Standard system components

– Industry accepted installation methods

• Successfully achieving sound goals requires

– Acoustical analysis of the desired system

• Modeling resources readily available

• Acoustical consultants available (NCAC, INCE, ASA) • Commercially available tools (from Trane, ASHRAE)

– Reliable sound data for all system components

Controls / Automation

• Interlocks

• Thermostats

Door and Window Interlocks

Door or Window Open

Air Conditioning Unit Compressor Off !

• Flexibility

• Reduced construction cost

• Robust communications • 5+ year battery life

• Easy installation

Automation Architecture

Multi-Purpose Controller VAVs RTU Unitary Controller Ethernet WAN/LAN BACnet/IP    Packaged RTU PC

with Web Browser

VAVs RTU    BACnet MSTP B BACnet MSTP A Controller

Controls / Automation

• Interoperability

– BACnet appears to now the “standard”

• Modernization:

– Allows competitive bidding of controls

– All major equipment and control mfg

– Full system implementation

• IP – District / Campus Level • MSTP – Building Level

Wired Communications

Building Controller Service Tool

VAV Controller Cooling Tower Control

Zone Sensor

VAV Controller BACnet Comm. Interface

Wireless Communications

Building Control

Service Tool

Tracer TU with TU Adapter

BACnet Comm. Interface

VAV Controller

Cooling Tower Control

Zone Sensor

Wireless Communication

•

Wireless Mesh

– Redundant, self healing networks – Leading HVAC wireless solution – Future Interoperability

• Latest ZigBee radios (2006 vs. Pro)

• Higher power radios

• Maximum range/reliability

– Factory installation

• Lower installed cost

Education Green Dashboard

• Customized software-as-a-service dashboard for K-12.

• Provides visualization of energy data and its effect on the

environment with students and facilities staff at K-12 schools.

• Aids a curriculum to support classroom learning.

• Districts leverage their investment in their school buildings and

infrastructure into the classroom learning

• Works with District automation to collect

How does the Education Green Dashboard work? Education Green  Dashboard   QAS Data  Center Servers School Computers  with Internet  Access Dashboard  Data  Gateway  Installed on  School’s PC  or Server BACnet Control  System Home Computers  with Internet  Access Meter School Lobby Classroom At Home Touchscreen Kiosk with  Internet Access

HVAC - Modernizations