Software for the yard running indirect-fired heaters.

An indirect-fired heater is the unit a yard sends when the heat has to go into a space people work in, or onto equipment that cannot get wet. The burner is sealed and vented through a flue, so the exhaust, the fumes, and the moisture of combustion never reach the supply air — only clean, dry heat moves down the duct. That is why these units run freeze protection on frac tanks, cure concrete in the cold, and warm enclosed bays where a direct-fired heater would not be safe. It is also why they are awkward to run as a fleet: every unit goes out with ducting, a thermostat, and a fuel plan, the hour meter climbs fast on a month-long winterization, and the cold itself is hard on fuel, burners, and exchangers. EquipFlow runs heaters the way the yard that built it does — one record per unit.

Built inside Rental King, right now.

Rental King is a heavy-equipment rental yard in Odessa and Midland, TX. They run indirect-fired heaters, manlifts, forklifts, light towers, generators, compressors, and water trucks on MSA contracts through the Permian Basin — 24/7, oilfield pace. EquipFlow was designed and first deployed inside that yard. Every feature was tested against their live operation before it shipped. The product runs there today.

Heaters are seasonal, high-utilization, easy-to-undercharge units, and that is where money leaks. A heater parked on a frac-tank pad for freeze protection earns nothing extra if the standby days never reach the invoice, and the ducting that left with it gets lost or torn if no inspection accounts for it on return. The hour meter drives both the burner PM and the billing, so it has to be captured the same way every time — at return, on the inspection, against the rental record. When dispatch, billing, maintenance, and inspection all read from one unit record, the dispatcher promises the right unit with enough duct to reach, the mechanic services the burner on real run hours, and the bookkeeper closes the month without reconstructing a long winter from memory. That single-record discipline is what keeps a heater fleet from bleeding through the cold season.

Indirect-Fired Heater specs the rental record tracks.

Every number below is a sourced specification range. The render layer is the only path these values reach the page — they live on the unit record, not in a dispatcher's head.

Heat output

350000-1000000BTU/hr

Heated-air output

2500-7060cfm

Thermal efficiency

81%

Diesel fuel consumption (full load)

3.0-6.0gph

Onboard fuel tank capacity

42-210gal

Maximum duct run

50-125ft

Exhaust flue diameter

6in

How EquipFlow handles indirect-fired heaters on the dispatch board.

An indirect-fired heater is rarely just the box on the trailer. It dispatches with ducting, a thermostat, and often a fuel plan, so the dispatch board treats the duct lengths, transitions, and the flue setup as line items confirmed against the rental record before the truck rolls. Sending a high-output unit to a job that needs a long duct run, then arriving without enough duct to reach the far corner of the tent, is a return trip. The board shows which heaters are staged, which are on location running, and which are due back, on the same responsive screen at any hour, because winter demand spikes overnight when a cold front lands and a dispatcher is assigning units in the small hours. Conflicts surface at assignment, not at the gate, so the same unit is not promised to two pads in one freeze.

Billing indirect-fired heaters — MSA, standby, and site-level tax.

Most cold-weather heater demand in the oilfield is MSA-contracted, so the negotiated rate lives as an override on the customer record per equipment class rather than in a sheet the dispatcher keeps. A heater rental created for that account picks up the right rate on its own. Winterization is the standby case made plain: a unit can sit on a frac-tank pad running through weeks of freeze protection while the crew works nothing on it, and those idle-but-billable days carry a standby rate separate from active days. The dispatcher marks standby and the invoice carries both lines without a month-end rebuild. Delivery, pickup, ducting, and fuel-fill charges ride the same invoice. Tax follows the delivery-site record, so a unit moved between counties through a long winter still bills the correct rate per site, and invoices post to QuickBooks Online on close.

Maintenance on indirect-fired heaters.

Heater PM is hour-meter driven, not calendar driven, because a freeze-protection unit can run nearly around the clock for a month while a yard spare waits out a mild stretch untouched. The hour-meter reading is captured on the return inspection and posts to the unit record, and the maintenance module advances the PM clock from that reading so the next service lands on real run time. The burner is the heart of the unit, so service leans on the fuel filter, the combustion nozzle, the igniter and flame sensor, and the heat-exchanger and flue condition alongside the blower motor and belts. A cracked or sooted heat exchanger is the failure that matters most, since it is what keeps combustion separate from the supply air. Work orders, parts, and meter history live on the unit record, which is also where a damage charge from a return inspection becomes a repair ticket.

Indirect-Fired Heater return inspections.

Two inspection rhythms apply. While the heater is on rent, the operator runs a daily check — fuel level, the burner lighting clean, the duct seated, the flue clear — and that is the customer's responsibility. The yard's own control is the return inspection. Before a heater comes off rent, the driver runs a mobile-web checklist on a phone with no app to install, records the hour-meter reading, and attaches required photos that cannot be skipped. Heater-specific checks belong here: the heat exchanger and flue for cracking and soot, the burner and nozzle, the blower and belt, fuel-system condition and leaks, and the ducting and transitions for tears and crushed sections. The inspection ties to the rental record before the truck leaves the site, so a damage dispute has photos and a timestamp behind it.

Common indirect-fired heater classes in the field.

The product, the same way it runs for indirect-fired heaters.

The sections below are the EquipFlow modules that matter most when running indirect-fired heaters — each links to the full feature detail.

Operator guides for running indirect-fired heaters.

Field-tested playbooks that go deeper on pricing, dispatch, billing, and maintenance for fleets like this.

• Adding a New Equipment Category to Your Yard →
• Air Quality Equipment Rentals →
• Compressed Air Equipment Rentals →
• Equipment Rental for Industrial Maintenance Shutdowns →

What you give up running indirect-fired heaters in EquipFlow.

EquipFlow is a web app, so the return inspection needs a signal to load. On a remote pad with no coverage, the driver cannot finish the mobile inspection at the site; most yards run it at the yard on return instead, which means the photos and hour reading land later than ideal. There is no built-in telematics today, so a unit's burner-runtime or fault data from a manufacturer portal is not pulled in automatically — the hour meter is captured at return. Fuel itself is not metered through the software; fuel fills are billed as charges, not read off a sensor. And the rate logic assumes the MSA-and-standby model the oilfield runs on, so an unusual billing setup should come to the demo to be scoped honestly.