Let me save you from the mistake I made in May 2022. Ignore the headline flow rate on Howden Roots blower specification sheets and start with the pressure range and speed curve. That one change would have kept our plant from buying the wrong blower and burning roughly $18,000 on rework, freight, and downtime.
If you found this page through "Howden commercial waste removal," I should be clear: I'm not talking about dumpsters or bin collections. I'm talking about the Howden Roots blowers used in commercial wastewater and waste-to-energy facilities. And if you're wondering where to buy a burner phone, this isn't that article either. But if you're responsible for specifying or replacing a Howden Roots blower, keep reading.
The mistake that reset my checklist
I've been handling gas and air handling equipment orders for six years—or rather, seven, counting the years before I officially handled budgets. In that time, I've personally made and documented four significant mistakes, totaling roughly $80,000 in wasted budget. This one was the most expensive, and it taught me to look at the fine print under the big numbers.
In 2022, we were retrofitting a blower at a commercial waste removal site. The old unit was a Howden Roots blower, and it kept tripping on high discharge pressure. I pulled up the replacement specification sheet and did what felt natural: compared maximum CFM numbers between suppliers. The option with the highest flow looked like the best value. It wasn't. When I compared the performance curves side by side, the "best" blower couldn't deliver our required flow at the pressure we needed. At our duty point, it was about 18% short. We installed it anyway, and discovered the problem during the startup test.
Seeing the two curves side by side made me realize why pressure matters as much as flow. It sounds obvious in hindsight, but the spec sheet had made it look simple.
What to actually check on Howden Roots blower specification sheets
The thing is, a Roots blower specification sheet is not a list of product features. It's a set of performance curves folded into a table. If you read only the flow column, you're missing the part that determines whether the blower will survive your application.
- Flow at your operating pressure, not maximum flow. A Roots blower is a positive-displacement machine, which means the relationship between speed, pressure, and flow is a curve. If the spec sheet lists 2,000 CFM at 5 psi and 1,200 CFM at 12 psi, you need to know which end of that curve you're buying.
- Speed and brake horsepower. More speed doesn't mean more value—it means more wear, more noise, and more power demand. Compare RPM and BHP at your duty point, not at the edge of the curve.
- Inlet conditions. Most spec sheets use standard inlet conditions: 101.3 kPa and 20°C. If your site is at altitude, in a hot building, or handling digester gas, the actual capacity will be lower. What I mean is that a blower rated for 1,000 CFM at standard conditions can deliver 850 CFM in summer at altitude, and that's before you account for dirty filters.
According to Howden's published product documentation (howden.com), performance data is referenced to specified inlet conditions. In my experience, more specification mistakes come from ignoring that note than from any other single cause.
Why a Mr. Heater label helped it click
One of my early jobs involved buying diesel heaters for a temporary warehouse. I remember looking at a Mr. Heater box and thinking, "This is just a spec sheet: BTU, tank size, done." For a heater, that works more or less. For a blower, it doesn't. A blower specification sheet describes a family of operating points, not a single output. That's why buying on the loudest number is dangerous.
When I compared the Howden datasheet and the old supplier quote side by side—same job, different pressure assumptions—I finally understood why the details matter so much. The difference wasn't the blower. It was the duty point.
What I do now
Now I follow a three-step rule before I send any Howden Roots blower specification sheet to a supplier for quoting. First, I define the duty point in writing: minimum and maximum inlet pressure, discharge pressure, temperature, and flow. Second, I ask the vendor to mark the operating point on their curve—not in an email, on the actual document. Third, I check the motor power after the performance curve, not before.
That rule would have caught the 2022 mistake in about ten minutes. Instead, the error survived for two months, through the purchase order and the factory test. It wasn't until the startup engineer asked why the blower was surging that someone looked at the curve. In Q3 2024, we sent the same duty point to three vendors and got pricing that varied by 30%. That wasn't a market signal—it was a spec signal. The vendors were quoting different curves.
When this advice doesn't apply
Here's where I need to be honest about my own limitations. I'm not a compressor engineer, so I can't speak to rotor profile design, internal clearances, or metallurgy. What I can tell you from a buyer's perspective is how to catch mismatches before they become purchase orders.
My experience is based on about 50 mid-sized blower packages—maybe 48, I'd have to check our tracker. If you're working with high-pressure hydrogen, refinery gas, or a process where API 619 compliance matters, your checklist will need different items. Get Howden's application engineers involved early. And if you're buying a diesel heater for a warehouse, ignore everything I just said—that's a completely different decision.
One last thing: if your search history includes "where to buy a burner phone," I can't help with that, and I'm not judging. But the most useful calls I've made about equipment weren't anonymous. They were to plant operators who ran the equipment we were considering. No burner phone can replace that.
