Evaporator & Condenser Views
What You'll Learn
- How to access the evaporator and condenser component views from the Diagnostics screen
- What measurements are displayed for each component and what they mean
- How failure indicators appear on the component views
- The SEER-to-CTOA 4-bucket system for condenser performance evaluation
- When to use component views vs. the overall Diagnostics screen
What You'll Need
- Device: iPhone (iOS 15+) or Android phone/tablet (Android 10+) with measureQuick installed
- Account: Logged in with an active measureQuick account
- Context: A test in progress or a completed test with diagnostic results on a cooling system (A/C or heat pump in cooling mode)
- Knowledge: Familiarity with the Diagnostics screen (see B14), basic refrigeration cycle concepts (see E1)
- Probes: At minimum, suction line temperature, liquid line temperature, high-side pressure, low-side pressure, and outdoor ambient temperature probes connected
- Time: 10 minutes to read; 15 minutes to walk through with a live or demo test
Step-by-Step Guide
Step 1: Access Component Views from the Diagnostics Screen
During or after a test, navigate to the Diagnostics screen (bottom navigation bar). The Diagnostics screen shows an overall system summary with pass/fail indicators for each subsystem.
To access the component-specific views:
- Look for the Evaporator and Condenser sections on the Diagnostics screen
- Tap on either section to open its dedicated component view
Diagnostics screen with Evaporator and Condenser sections visible, showing tap targets
Each component view focuses on one side of the refrigeration cycle. The evaporator view shows indoor coil performance. The condenser view shows outdoor coil performance. Separating them makes it easier to isolate which component is contributing to a system fault.
Step 2: Read the Evaporator View
The evaporator view displays measurements related to the indoor coil and low side of the refrigeration system.
Key measurements shown:
| Measurement | What It Tells You |
|---|---|
| DTD (Design Temperature Difference) | The difference between return air and supply air temperature. Indicates how much cooling the evaporator is producing. Typical target: 18-22F for standard cooling. |
| Suction Pressure | Low-side pressure at the compressor inlet. Directly related to evaporator temperature. |
| Superheat | Temperature of the suction gas above its saturation point. Indicates whether the evaporator is receiving the correct amount of refrigerant. Low superheat suggests flooding; high superheat suggests starvation. |
| Return Air Temperature | Air entering the evaporator coil. Provides context for DTD and capacity calculations. |
| Supply Air Temperature | Air leaving the evaporator coil. The difference between return and supply is the DTD. |
| Evaporator Saturation Temperature | The boiling point of the refrigerant at the measured suction pressure. Used to calculate superheat. |
Indoor Measurements showing Return/Supply temps, %RH, estimated airflow, and test procedure picker
Each measurement has a color-coded indicator: green (pass), yellow (warning), red (fail), or gray (not measured). Tap any measurement row to see the target range, current value, and an explanation of the result.
Step 3: Read the Condenser View
The condenser view displays measurements related to the outdoor coil and high side of the refrigeration system.
Key measurements shown:
| Measurement | What It Tells You |
|---|---|
| CTOA (Condenser Temperature Over Ambient) | The difference between the condenser saturation temperature and the outdoor ambient temperature. This is the primary indicator of condenser performance. |
| Liquid Pressure | High-side pressure. Directly related to condenser saturation temperature. |
| Subcooling | Temperature of the liquid refrigerant below its saturation point. Indicates whether the condenser is fully condensing the refrigerant. Low subcooling may indicate low charge; high subcooling may indicate overcharge or restriction. |
| Outdoor Ambient Temperature | Air entering the condenser coil. Required to calculate CTOA. |
| Condenser Saturation Temperature | The condensing point of the refrigerant at the measured liquid pressure. Used to calculate subcooling and CTOA. |
Condenser detail view showing CTOA, liquid pressure, subcooling, outdoor ambient, and saturation temperature with indicators
Step 4: Understand the SEER-to-CTOA 4-Bucket System
measureQuick uses a SEER-based target system for CTOA evaluation. The expected CTOA depends on the equipment's rated efficiency. Higher-efficiency equipment is designed to reject heat with a smaller temperature difference between the condenser and outdoor air.
The four CTOA target buckets:
| SEER Rating | CTOA Target |
|---|---|
| 6-9 SEER | 30F |
| 10-12 SEER | 25F |
| 13-16 SEER | 20F |
| 17+ SEER | 15F |
measureQuick pulls the SEER rating from the system profile you configured during project setup. If the equipment profile includes a SEER rating, the condenser view automatically applies the correct CTOA target.
A CTOA significantly above the target indicates the condenser is not rejecting heat efficiently. Common causes: dirty condenser coil, restricted airflow over the outdoor unit, non-condensable gases in the system, or overcharge.
A CTOA below the target is less common but may indicate low charge (less refrigerant to condense, so the condenser "overcools" what is there) or an oversized condenser relative to the compressor.
Choose SEER/CTOA screen with Standard tab showing four efficiency tiers and CTOA target values
Step 5: Interpret Failure Indicators on Component Views
Failure indicators on the component views work the same way as on the main Diagnostics screen (see B14):
- Green - the measurement is within the target range for this component
- Yellow - minor fault; outside the ideal range but within a broader tolerance
- Red - major fault; outside the acceptable range
- Gray - not measured; the required probe is not connected or not reporting data
When a component view shows red, the detail for that measurement explains what is out of range and by how much. The component views make it straightforward to see whether a problem is on the evaporator side, the condenser side, or both.
For example, if the evaporator view shows high superheat (red) while the condenser view shows normal subcooling (green), the issue is likely on the low side - a metering device restriction, low charge reaching the evaporator, or insufficient airflow across the indoor coil. If both sides show faults, the root cause may be system-wide, such as an incorrect refrigerant charge.
Step 6: When to Use Component Views vs. the Overall Diagnostics Screen
Use the overall Diagnostics screen for a quick system health check. It gives you the Vitals Score, all subsystem pass/fail indicators, and the stability status in one view. Start here for every test.
Use the component views when:
- The overall Diagnostics screen shows a refrigerant charge failure and you need to determine which side of the system is causing it
- You want to show a customer the specific performance of their indoor or outdoor unit
- You are troubleshooting and need to see all related measurements for one component grouped together
- You are comparing evaporator and condenser performance side by side to isolate a fault
The component views do not replace the Diagnostics screen. They provide a focused perspective on one half of the refrigeration cycle for deeper analysis.
Video Walkthrough
measureQuick Diagnostics: Behind The Curtain: (4,695 views, 9:22) - Covers the diagnostic engine, including component-level evaluation
Introduction to measureQuick: (13,518 views, 1:30:48) - Comprehensive walkthrough including diagnostic screens and subsystem detail views
Tips & Common Issues
The condenser view does not show a CTOA target
CTOA targets require a SEER rating in the system profile. Go to the project's system profile and enter the equipment SEER rating. If you do not know the SEER rating, check the equipment nameplate or use the AI System Profiler (D1) to identify the unit.
Superheat and subcooling readings seem wrong
Verify that your pressure probes are connected to the correct ports (high side to the liquid/discharge line, low side to the suction line). Swapped pressure connections produce inverted calculations. Also confirm the correct refrigerant type is selected in the system profile, as saturation temperatures are refrigerant-specific.
Gray indicators on evaporator measurements
Gray means the app has no data for that measurement. Confirm the suction line temperature probe and low-side pressure probe are connected and transmitting. Check probe connection status on the measurement screen (see Test Mode Navigation).
Should I use CTOA or subcooling to evaluate condenser performance?
Both. CTOA tells you how efficiently the condenser rejects heat relative to outdoor conditions. Subcooling tells you whether the refrigerant is fully condensing before it leaves the condenser. A system can have normal subcooling but elevated CTOA (dirty condenser reducing efficiency), or normal CTOA but low subcooling (undercharge). Evaluate both together.
My SEER rating is between two buckets
measureQuick assigns the bucket based on the SEER value in the system profile. A 12.5 SEER unit falls into the 10-12 bucket (25F CTOA target). If you believe the target does not match your equipment, check the manufacturer's specifications for the rated CTOA and compare.
Related Articles
Prerequisites:
Follow-up articles:
- Reading Diagnostic Flags - interpreting specific fault codes
- Fault Types: Minor vs Major - understanding escalation from component faults
- Subcooling and Superheat - detailed measurement interpretation
- HVAC Vitals Score - how component results feed into the overall score
Related in the same domain:
- Test Mode Navigation - probe connection and live measurement screens
- Grid View - alternative measurement layout
Related in other domains:
- A/C Installation Workflow - component views during installation commissioning
- System Stabilization - readings must stabilize before evaluating component views
Need Help?
Contact measureQuick support: support@measurequick.com
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