Before you spend thousands on new equipment, it pays to know exactly where your energy is being wasted.
A few inexpensive tools can help you:
- See where heat or cool air is escaping,
- Identify under-insulated areas,
- Spot appliances that draw more power than they should.
This guide covers the best DIY energy audit tools and how to use them—so you can prioritize fixes that actually move the needle on your energy bill.
Quick Comparison: Best Energy Audit Tools
| Tool | What It Does | Price Range | Best For |
|---|---|---|---|
| FLIR ONE Pro (Thermal Camera) | Visualizes heat loss, air leaks, insulation gaps | $349–$399 | Serious DIYers, whole-home assessment |
| Seek Thermal Compact (Budget Thermal) | Basic thermal imaging via smartphone | $199–$249 | Budget-conscious homeowners |
| TP-Link Kasa KP125M (Smart Plug) | Monitors per-appliance energy use | $15–$20 each | Finding energy hogs, appliance monitoring |
| Emporia Vue Gen 3 (Whole-Home Monitor) | Tracks every circuit in real time | $139–$159 | Whole-home energy visibility |
| P3 Kill A Watt EZ (Plug-In Meter) | Measures appliance wattage and cost | $25–$35 | Quick appliance checks, no app needed |
Tool #1: Thermal Camera — See Where Your Energy Is Escaping
A thermal camera is the fastest way to “see” where your home’s building envelope is underperforming. It detects temperature differences on surfaces, making air leaks, missing insulation, and drafty windows immediately visible as color variations on your phone screen.
You don’t need a professional-grade camera for a DIY home audit. A mid-range smartphone attachment or standalone unit works well for identifying the biggest problem areas.
FLIR ONE Pro
The FLIR ONE Pro attaches to your smartphone and gives you a live thermal image overlaid with a regular camera view (called MSX imaging), making it much easier to interpret what you’re seeing. It has a 160×120 thermal resolution—more than enough for home energy audits.
✓ Why We Like It
- MSX imaging makes thermal images easy to read
- Works with iOS and Android (check connector type)
- FLIR app is excellent for saving and sharing images
- Durable, professional-grade build
✗ Worth Knowing
- Higher price than budget alternatives
- Must match your phone’s connector (Lightning or USB-C)
Best for: Homeowners who want to do a thorough audit and may use the camera again for future inspections or maintenance checks.
Price range: $349–$399
View on Amazon →Seek Thermal Compact
If the FLIR ONE Pro is more than you want to spend, the Seek Thermal Compact is a solid budget alternative. It has lower resolution (206×156) but is more than adequate for spotting drafts, missing insulation, and air leaks around windows and doors.
Price range: $199–$249
View on Amazon →Tool #2: Energy Monitoring Smart Plugs — Find Your Appliance Energy Hogs
Smart plugs with energy monitoring let you see exactly how much electricity each appliance is drawing—and calculate what it costs you per month. This is one of the most eye-opening exercises you can do: most homeowners are surprised by how much certain appliances (old refrigerators, space heaters, gaming consoles) actually cost.
TP-Link Kasa KP125M
The Kasa KP125M is consistently rated the best energy monitoring smart plug by independent reviewers. It tracks real-time wattage and cumulative kWh usage, integrates with Alexa, Google, and Apple HomeKit, and the Kasa app is one of the cleanest and most reliable in the category.
✓ Why We Like It
- Accurate energy monitoring with kWh tracking
- Works with all major smart home platforms
- Slim profile—doesn’t block the second outlet
- Reliable app with usage history
- Affordable—buy several to test multiple appliances
✗ Worth Knowing
- Only works with 2.4 GHz Wi-Fi
- Indoor use only
Best for: Identifying which appliances are costing the most, setting up schedules to reduce standby power, monitoring specific circuits.
Price range: $15–$20 each (often available in 4-packs)
View on Amazon →P3 International Kill A Watt EZ
If you don’t want a smart home app, the Kill A Watt EZ is a simple plug-in meter that shows you real-time wattage, cumulative kWh, and estimated monthly cost right on its display. No Wi-Fi, no app, no account—just plug it in and read the numbers.
Price range: $25–$35
View on Amazon →Tool #3: Whole-Home Energy Monitor (Advanced)
Smart plugs tell you about individual appliances. A whole-home energy monitor tells you about everything—every circuit in your home, in real time. It installs in your electrical panel and uses current sensors to track usage across all circuits simultaneously.
Emporia Vue Gen 3
The Emporia Vue Gen 3 is the most popular whole-home energy monitor for DIY installation. It includes 16 individual circuit sensors, so you can see exactly how much each circuit (HVAC, water heater, EV charger, kitchen, etc.) is consuming at any moment. The app is well-designed and shows historical trends that help you spot unusual usage patterns.
✓ Why We Like It
- 16 individual circuit sensors included
- Real-time and historical usage data
- Integrates with solar systems and EVs
- DIY installation (comfortable with electrical panels)
- Excellent app with cost tracking
✗ Worth Knowing
- Installation requires working in your electrical panel—hire an electrician if you’re not comfortable
- Monthly subscription for some advanced features
Best for: Homeowners who want complete visibility into their energy use, especially useful before and after solar installation to measure actual savings.
Price range: $139–$159
View on Amazon →How to Use These Tools in a Weekend
Your Weekend Energy Audit Checklist
- Walk the home with a thermal camera. On a cold day (or hot day in summer), scan all exterior walls, windows, doors, attic hatches, and electrical outlets on exterior walls. Mark anything that shows a significant temperature difference—these are your air leaks and insulation gaps.
- Test key appliances with smart plugs. Plug in your refrigerator, chest freezer, window AC units, space heaters, and any other suspected energy hogs. Let each one run for at least 24 hours to get an accurate daily kWh reading. Multiply by 30 for monthly cost.
- Install a whole-home monitor (optional). If you want the full picture, install an Emporia Vue or similar device. Run it for 1–2 weeks to establish a baseline before making any changes.
- List your top issues by potential savings. Rank your findings: air sealing and insulation typically give the best return, followed by replacing inefficient appliances, then behavioral changes.
- Use the free guide to prioritize fixes. Our Energy Savings Guide includes a prioritized checklist of the 25 most impactful improvements, ranked by difficulty and expected savings.
Want to Cut Your Energy Bill Without Guessing?
Download our free Energy Savings Guide—25 proven, homeowner-tested ways to use less energy and stay comfortable.
Get the Free Guide →Disclosure: Some links on this page are affiliate links. If you purchase through them, NRGplex may earn a small commission at no extra cost to you. We only recommend products we believe are genuinely useful.
