Signature product
Negawatt Chiller Performance Study
We temporarily instrument your cooling plant and measure how it actually performs under real operating conditions, typically over four weeks of continuous logging.
The objective is not a spot reading. It is the actual performance curve of the plant in kW/RT.
What happens on site
01
Survey
Site suitability, plant access, and measurement boundary
02
Install
Temporary instrumentation via approved field partners
03
28-day log
Continuous data under real operating conditions
04
Remove & report
Equipment out; kW/RT analysis and findings delivered
Subject to site suitability. Field work may be delivered by Negawatts.io directly or through approved partners, depending on location, geography, scale, procurement, and capability. This path aligns with the vChill plant performance offer. DIFY field studies are sized for opportunities with indicative annual conservation value of SGD 50,000 or more, so the journey fits the prize. Smaller opportunities stay on DIY tools and DIWY support until the quantum justifies field work.
Measured vs target performance
Industry practice often treats about 0.65 kW/RT as a typical plant norm band. On this platform the performance target is 0.58 kW/RT at 8.5°C supply condition. Always separate measured performance from targets, and state the temperature condition with the target.
Illustrative measured
1.38 kW/RT
Poor / unoptimised plant example
Typical norm band
~0.65 kW/RT
Common whole-plant reference
Platform target
0.58 kW/RT
At 8.5°C · benchmark, not labelled AFTER unless measured
Where the kW/RT goes
Typical plant intensity includes design, commissioning gaps, controls, and maintenance. Optimised operation cuts the stack, not just one component.
Water side
Chillers + CHWPs + CWPs + CTs
kW/RT · design baseline ≈ 0.85 shown in stack body
Air side
AHUs + FCUs
kW/RT · design baseline ≈ 0.40 shown in stack body
Illustrative redraw from engineering practice (IDPM-style analysis). Percentages and levels are not a site guarantee. Align with measured plant data on each project.
Methodology
How we measure plant performance
Equations, component budgets, and instrument uncertainty so engineers can see the method, not only the marketing.
System efficiency budget
Specific power is the sum of plant components. Improve the whole system, not only the chiller nameplate.
| Component | Typical kW/RT | Improved kW/RT |
|---|---|---|
| Chiller | 0.54 | 0.47 |
| CHWP | 0.04 | 0.04 |
| CWP | 0.04 | 0.04 |
| CT | 0.03 | 0.03 |
| Sys Eff | 0.65 | 0.58 |
Cooling load (RT)
RT ≈ [Flow × ΔT × constant] / 24
System efficiency = kW / RT. Site target on this platform is 0.58 kW/RT at 8.5°C supply condition, with ~0.65 kW/RT as a common norm band. Always label measured vs target and state the temperature condition.
Illustrative component budget redrawn from engineering practice. Not a guarantee for any site.
Measurement uncertainty
Temporary instrumentation is specified so total system uncertainty stays within accepted plant performance guidelines.
| Unit | Allowable uncertainty | Instrument |
|---|---|---|
| kW | 1.0% or better | Power meter with factory-certified CTs |
| Flow | 2.0% or better | Ultrasonic or magnetic flow meter |
| Temp | 0.5% or better | Thermistor with high-resolution instrument |
| Stability | 1.0% | Sustained reading stability under load |
Total system uncertainty ≈ ±5%
Per ASHRAE Guideline 22 practice and Singapore Green Mark plant efficiency measurement context. ΔT uses two temperature sensors. Site protocols may tighten these limits.
01 Measure
Establish existing performance
Continuous temporary instrumentation and kW/RT analysis under real loads.
02 Optimise
Improve operations
Identify and implement operational improvements with engineering and controls partners.
03 Verify
Measure again
Re-measure after intervention. Build the evidence path toward Proof of Conservation, without implying automatic NWT issuance.