# Presentation: 098144

## ASHRAE Seminar #46Diagnostics from an Operations Perspective: Needs and ExperiencesWeb-based Information Tools for Reporting Air Conditioning Service Data

- by
- Roy Crawford
- Honeywell Home and Building Controls
- Minneapolis, Minnesota
- January 31, 2001

## Why Collect and Report AC Service Information?

- Verify that proper service was performed
- Bill verification
- Warranty authorization?
- Provide equipment history for later analysis
- Maintenance histories
- Performance trends

## Why Use the Web?

***It’s being used for everything else!***

- It is already there, practically free
- Allows multiple users
- Service technicians and contractors
- Building owners
- Equipment manufacturers?
- Only requires web browser software on PC

## Options for Transferring Service Information to the Web

- Manually
- Permanently installed equipment
- Portable electronic service tool

## Manual Data Collection

- Use conventional pressure gauges and thermometers
- Record data with pencil and paper
- Manually enter data via web-browser

***Slow, tedious process***
***Prone to errors***

## Permanently-Installed Equipment

***Continuous monitoring***
- detect intermittent faults
- analyze real-time performance
- on-board diagnostics
***Instantaneous alarming***
***Can allow remote control***

***High costs ****(*electronics, sensors, installation, communications)
***Doesn’t eliminate all site visits**** *(filter changes, etc.)
***Used on Critical Applications***

## Portable Electronic Service Equipment

- Temporarily connect pressure and temperature sensors
- Monitor, analyze, and record performance on PDA
- Can also log inspection and service tasks on PDA
- Direct data transfer to Web (land line or wireless)

*Faster, more accurate than manual methods*
*Often more cost-effective than permanently-installed systems*

## Measured Data Options

**Air Temperatures**
- Indicate capacities
- Relatively cheap sensors
**Refrigerant (Suction and Liquid) Pressures and Temperatures, Outdoor Temperature**
- Indicate system “health”
- Relatively expensive (pressure sensors) for permanent installations
**Cutout Switches**
- Indicate faults, out-of-service
- “Free” sensors (OEM-installed), cheap electronics (digital)
**Flow meters, Humidity, etc.**
- Expensive and/or unreliable

**T**

**T**

**T**

**T**

**T**

**P**

**P**

- suction

- discharge

- liquid

- return
- air

- supply
- air

- outdoor
- air

- leaving
- air

**P**

**P**

**T**

## Other Information Options

**Automatically Generated from Measured Data**
- Derived performance variables
- Superheat, subcooling, coil splits, etc.
- Diagnoses
- Dirty coils, low refrigerant charge, etc.
- Equipment performance
- System capacity, efficiency?
**Manually Entered by Service Technician (PDA)**
- Inspection data
- Checked belts, changed filters, etc.
- Service performed
- Added charge, cleaned coils, etc.

## Information Access

- AC Unit

- Measurement Unit, PDA, etc.

- Modem

- ISP

- phone
- line

***World Wide Web (Internet)***

- Cell Phone, Pager, etc.

- Wireless
- Com. Co.

- Web Browser
- (Building Owner)

- Web Browser
- (Contractor)

- Web Browser or Server
- (OEM)

- RF

- Web Server
- (service contractor or
- 3rd party service)

## A/C Analyzer Web Server Functions

**Central Database of AC Unit Performance**
- Inspection and routine maintenance tasks performed (check belts, replace filters, etc.)
- Any unplanned service performed (add charge, replace compressor, etc.)
- Operating conditions before and after service
**Application Programs**
- Review/verify service performed on individual units
- Provide historical performance trends
- most common faults, failures, required service, etc.
- sorted by location, technician, equipment type, etc.

## Web Report:  Unit Performance

**Web Report:  Unit Performance**

***Measured Data***

***Calculated Quantities***

***Diagnosis***

***Service Performed***

## Web Report:  Site Equipment Summary

*Review service data*
*Schedule additional maintenance*
*Ensure proper equipment installation/repair*
*Authorize bill payment*

## Web Report:  Efficiency Data

***Detect performance degradation***
***Estimate benefits from servicing***

- Efficiency Index

- Currently Estimated
- Efficiency

- Estimated Efficiency
- after Servicing

- =

- Actual Field Data from 1400 Rooftop AC Units

## Possible Information Interactions

## Conclusions

*Collecting data and uploading to Web*
- Manual
- Too tedious and error-prone to be useful
- Permanently-installed equipment
- Expensive, but good for critical applications
- Smart service equipment
- Cost effective for many applications
*Web-based data reporting and analysis*
- Can provide numerous useful interactions between *service personnel*, *building owners*, and perhaps even *equipment manufacturers*