Last updated: August 13, 2026. By Dan McKenna, founder, Elite Energy Management.
The short answer: it depends on what your buildings already have. If your locations run an energy management system or connected thermostats, software-only monitoring layers AI fault detection onto the data those systems already produce, with no installation, no capital cost, and results in weeks. If a site has no controls at all, hardware has to come first. Many multi-site operators end up using both.
What is software-only HVAC monitoring?
Software-only HVAC monitoring connects to the systems a building already has, an energy management system, connected thermostats, or existing sensors, and analyzes the data they already produce. Temperatures, setpoints, compressor and fan staging, runtimes, and outdoor conditions are read continuously and screened by AI for the early signatures of developing faults: refrigerant loss, failed cooling stages, short cycling, airflow problems, and units that quietly work harder every week to hold the same temperature.
Because nothing is installed, deployment is measured in days rather than site visits. The upside of catching faults early is well documented. According to the U.S. Department of Energy, fault detection and diagnostics tools could deliver up to 50 percent HVAC and refrigeration energy savings if widely adopted. Software-only platforms exist to make that kind of detection practical without a construction project.
What is hardware-bundled HVAC monitoring?
Hardware-bundled monitoring ships its own equipment: controllers, meters, sensors, gateways, and often replacement thermostats, installed at every location and connected to the vendor's platform. Pricing usually takes one of two shapes. Most commonly, the hardware and installation are paid upfront and a monthly fee for platform access continues on top. Some vendors instead roll everything into a single per-location monthly subscription, which typically runs on multi-year terms.
The added hardware buys granularity. Circuit-level metering can attribute energy use to individual pieces of equipment, and dedicated sensors can watch things a thermostat cannot see. The tradeoffs are real, though: capital or long-term contract commitments, an installation visit at every site, and equipment that ties the building to one platform.
How do the two approaches compare?
| Software-only | Hardware-bundled | |
|---|---|---|
| Upfront cost | None | Hardware and installation typically paid upfront, or rolled into a multi-year subscription |
| Installation | None, connects to existing systems | Site visit at every location |
| Time to first insight | Days to connect, a few weeks to learn each unit's normal behavior | Weeks to months, gated by installation schedules |
| Ongoing cost structure | Monthly software subscription, typically per unit | Monthly platform fee on top of the hardware purchase, or an all-in per-location subscription |
| Typical contract length | Monthly or annual | Annual to multi-year, longest when hardware is financed into the fee |
| Monitoring depth | Everything the existing controls can see: temperatures, staging, runtimes, setpoints | Adds circuit-level metering and dedicated sensors |
| Site requirement | An existing EMS or connected thermostats | None, works at sites with no controls |
| Switching later | Cancel the subscription, your systems and data sources stay in place | Installed equipment may need removal or replacement |
| Best fit | Sites that already have controls, operators who want fast proof | Sites with no controls, operators who want one vendor to own equipment and software together |
What does each approach cost?
The difference is structural, not just a number. On the hardware route, the most common pattern is equipment and installation paid upfront, with a monthly fee for platform access continuing on top. Some vendors instead fold everything into one per-location subscription, which is where multi-year terms come from: the fee has to recover the equipment and installation over time. Software-only platforms price per unit per month because there is nothing to recover, and nothing to pay before day one. Elite Energy Management costs $5 to $18 per rooftop unit per month depending on tier, so a typical restaurant with four rooftop units lands between $20 and $72 per month, with a 10 percent discount for annual prepay.
Cost matters more in some buildings than others. According to EPA ENERGY STAR, restaurants use about five to seven times more energy per square foot than typical commercial buildings, and high-volume quick service locations can reach ten times. At that intensity, a rooftop unit that degrades quietly gets expensive fast, and a monthly monitoring fee is small against a single avoided emergency service call.
When is software-only the right choice?
Software-only monitoring is the right starting point when your sites already have an energy management system or connected thermostats, such as eViewIoT or Pelican Wireless, because the data needed for fault detection already exists and is going unanalyzed. It also fits operators who want proof before commitment, since a pilot can run on live building data within weeks, and operators who would rather not add another capital project or multi-year contract. And it is the only approach that pencils for portfolios of smaller buildings, where per-site installation economics never work out.
When does hardware-bundled make sense?
Hardware-bundled monitoring makes sense when sites have no connected controls at all, since analytics cannot run on data that does not exist. It also fits operators who want circuit-level energy attribution across everything in the building, not just HVAC, and operators who prefer a single vendor accountable for the equipment and the software together. If thermostat or controls replacement is already planned, bundling monitoring into that project can be efficient.
Can you combine the two approaches?
Yes, and multi-site operators often should. Run software-only monitoring across the sites that already have controls, which is usually most of the fleet, and add hardware only at the locations that have nothing. The same analytics layer then watches every site the same way.
That is how Elite Energy Management deploys today: AI monitoring across nearly 1,000 rooftop units at more than 250 commercial locations in 28 states, reading every unit once a minute, more than a million readings a day. Most of those sites needed no new hardware at all. Where a site had no controls, partner hardware went in first and the monitoring layer followed.
Frequently asked questions
Do I need to replace my thermostats to get HVAC fault detection?
No. If your buildings already have an energy management system or connected thermostats, software-only monitoring reads the data those systems produce. Replacement only comes up when a site has no connected controls at all.
Does software-only monitoring work at sites with no EMS or smart thermostats?
No. Software-only monitoring needs an existing data source. Sites without connected controls need at least basic hardware, connected thermostats at minimum, before any analytics layer can watch them.
Is software-only monitoring less accurate than hardware-based monitoring?
Extra sensors add granularity, especially circuit-level energy metering. But the data existing controls already produce, temperatures, staging, runtimes, and setpoints, is enough to catch the most common and most expensive failure modes, including refrigerant loss, failed cooling stages, and short cycling, and to spot units degrading long before anyone in the building notices.
How long before software-only monitoring produces results?
Data starts flowing within days of connecting. Clear-cut problems surface almost immediately, and detection gets sharper over the first few weeks as the system learns each unit's normal behavior.
What does Elite Energy Management cost?
$5 to $18 per rooftop unit per month depending on tier, with a 10 percent discount for annual prepay. No hardware, no installation, no long-term contract required.
If your locations already have an energy management system, the fastest way to evaluate software-only monitoring is to see it on your own buildings. Elite Energy Management offers a free fleet health assessment: read-only access to your existing EMS, a scored report on every unit within one week, no hardware, no commitment. Request yours here.
Related reading: a plain-English guide to fault detection and diagnostics and how to monitor HVAC across all your locations without installing anything.