Integrating a Saving Energy controller in Existing Air Condition units

Case Study

TLC - Temperature Limit Control

Unit requirements

• Fits to any existing A/C (Air Condition) system

• Does not require any modification in the existing controller of the A/C

• Hidden inside the A/C unit

• Enables limits for both Cooling and Heating

• Saving Energy will not disturb the users of the A/C

• Easy, quick and simple installation

TLC – miniature Temperature Limit Controller

TLC – operation mode

T1 – Return Air Temperature sensorT1 – Return Air Temperature sensor

T2 – Supply air Temperature sensorT2 – Supply air Temperature sensor

Supply230VACSupply

230VAC A/C controller output to compressor lineA/C controller output to compressor line

To CompressorTo Compressor

Heating Temp . Limit knob

Heating Temp . Limit knob

Cooling Temp. Limit knob

Cooling Temp. Limit knob

TLC – Features

• Saves energy and electricity costs without disturbing the A/C users

• Overriding the energy waste of end-users who select high Heating set-point and

low Cooling temperature set-point

• Very small unit that fits into any existing A/C system

• Very Simple (2 knobs) adjusting

• Easy installation – Does not require any external or internal preparations

Test procedure• The test was made along 6 months in 4 different departments

• TLC was installed in each A/C on the output line from the control electric

board of the A/C to the compressor

• 2 Time counters were installed in each A/C

• Counter 1 – on the line before the TLC (counting the hours that the A/C

controller set the compressor to work)

• Counter 2 – on the line after the TLC (counting the hours the

compressor is actually working)

Test procedure

From the A/C control box

To A/C compressor

Counter 1 Counter 2

Results by departments

AREACounter 1 (hours)

(before TLC)

Counter 2 (hours)

(after TLC)Energy Saving %

Department 1

(Electric dept.)38015460%

Department 2

(Fire Safety dept.)25515539%

Department 3

(Sanitation dept.)1244167%

Department 1

(A/C dept.)44737217%

Saving Average:40%

The test showed an average of 40% saving in the working hours of the

compressors comparing to A/C units without TLC installed

Air Condition units (window, top, split, mini-central)

Total labor hours (yearly) @ plant 2400

Total working hours for 1 A/C (60% of the time) 1440

Average energy consumption of A/C 2.5 KW

KW/Hour cost (localy) 13.5 cents

A.C operation cost per hour 2.5 * 13.5 = 33.75 cents

Total yearly expenses per A/C without TLC 1440 (hours) * 0.3375 cents

= 486 US$

Total savings per A/C per year (30% calculation) is 145.80 US$

Savings calculations

Total savings for one A/C unit (yearly) 145 US$

Investments costs (TLC + installation) 100 US$

Return of investment within 8 months (100/145 = 0.68)

A/C units in plant 7000

Summary

Total yearly savingsTotal yearly savings

7000 * 145 US$ = 1015000 US$7000 * 145 US$ = 1015000 US$

Adding TLC in all 7000 plants A/C units

Will save 1 Million US$ On yearly electricity bills -

Which are

5% of the total Electricity bills of the plant

Conclusion