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Quotes - Engineering - SalesHigh Inlet Temperature Refrigerated Air Dryers, 20 to 125 SCFM
Dryers built for 180 to 200°F air straight off a piston compressor
A reciprocating compressor without an aftercooler discharges air at 180 to 200°F, and a standard refrigerated dryer rated for 100°F inlet either trips on high pressure or dries at less than half its nameplate. The dryers on this page are built for that air: they cool it, separate the water that condenses, and deliver dry air to a 2 to 30 hp shop, service bay or small plant without an aftercooler in front of them.
Two current series cover the duty. One accepts 200°F inlet air in five sizes from 25 to 100 SCFM with a zero-loss drain and a smart controller; the other takes 180°F air in five sizes from 25 to 125 SCFM and is built to sit next to the compressor with a matched high-temperature inlet filter. Both run from a 115 V cord. The retired 180°F series, 20 to 125 SCFM, is listed with its successor.
Cooling 200°F air costs refrigeration capacity, so these dryers deliver a 50°F pressure dew point, ISO 8573-1 class 6, rather than the 38°F of a standard dryer. For tools, tire machines, lifts and blow-off air that is more than enough; a paint line or a process needing class 4 air gets an aftercooler and a standard dryer instead.
- Rated for 180°F or 200°F inlet air from piston compressors with no aftercooler
- 20 to 125 SCFM covers 5 to 30 hp reciprocating compressors
- 115 V single phase, 1/2 in to 1 in NPT, integrated separator and drain
- 50°F pressure dew point, ISO 8573-1 class 6, at rated flow
Every high inlet temperature model
Sixteen models rated at their high-temperature inlet conditions and 100 psig. The two current series come first; the retired series follows with the series that replaces it.
| PART NUMBER | SERIES | SCFM | CONNECTION | VOLTAGE | STATUS |
| HRHT25A | HRHT Series | 25 | 3/4 in MNPT | 115/1/60 | Current |
| HRHT35A | HRHT Series | 35 | 3/4 in MNPT | 115/1/60 | Current |
| HRHT60A | HRHT Series | 60 | 3/4 in FNPT | 115/1/60 | Current |
| HRHT80A | HRHT Series | 80 | 3/4 in FNPT | 115/1/60 | Current |
| HRHT100A | HRHT Series | 100 | 1 in FNPT | 115/1/60 | Current |
| HTR 0025 | HTR Series | 25 | 1/2 in MNPT | 115/1/60 | Current |
| HTR 0050 | HTR Series | 50 | 1 in FNPT | 115/1/60 | Current |
| HTR 0075 | HTR Series | 75 | 3/4 in FNPT | 115/1/60 | Current |
| HTR 0100 | HTR Series | 100 | 3/4 in FNPT | 115/1/60 | Current |
| HTR 0125 | HTR Series | 125 | 3/4 in FNPT | 115/1/60 | Current |
| HITN20 | HITN Series | 20 | 3/4 in NPT | 115/1/60 | Replaced by HRHT |
| HITN25 | HITN Series | 25 | 3/4 in NPT | 115/1/60 | Replaced by HRHT |
| HITN35 | HITN Series | 35 | 3/4 in NPT | 115/1/60 | Replaced by HRHT |
| HITN50 | HITN Series | 50 | 1 in NPT | 115/1/60 | Replaced by HRHT |
| HITN75 | HITN Series | 75 | 1 in NPT | 115/1/60 | Replaced by HRHT |
| HITN125 | HITN Series | 125 | 1 in NPT | 230/1/60 | Replaced by HRHT |
Three series for hot inlet air
Why a standard dryer fails on hot air
Air at 190°F holds roughly ten times the water of air at 100°F, and every pound of that water must be condensed by the refrigeration circuit. A standard dryer's evaporator and condenser were sized for the 100°F case; fed 190°F air it runs its compressor at the limit, trips on high discharge pressure on a warm afternoon, and passes wet air the rest of the time. A high-inlet-temperature dryer has a larger condenser and exchanger for its nominal flow, a separator ahead of the chiller to take the bulk condensate, and a drain sized for the volume, which on a 10 hp piston compressor can be several gallons a day.
Which compressor, which size
Piston compressors deliver 3.5 to 4 SCFM per horsepower, so a 5 hp unit is 18 to 20 SCFM and the 25 SCFM model, a 7.5 hp is 26 to 30 and the 35 SCFM model, a 10 hp is 35 to 40 and the 50 SCFM, a 15 hp is 52 to 60 and the 60 or 75, a 20 hp is 70 to 80 and the 80 or 100, and a 25 to 30 hp is 87 to 120 and the 100 or 125 SCFM model. Two-stage compressors run somewhat cooler than single-stage machines but still above 150°F without an aftercooler, so they belong here too.
What is in the box
The 200°F line uses a brazed-plate exchanger on the 25 and 35 SCFM units and an aluminum plate-fin exchanger on the 60 to 100 SCFM units, an integrated moisture separator, a zero-loss electronic drain, and a controller with LED diagnostics, alarm history and, on the larger sizes, energy-saving fan control; the refrigerant is low-GWP R513A. The 180°F direct-expansion line puts a water separator ahead of the chiller, fits a zero-air-loss drain and a digital dew point display, and is offered with a 1 micron inlet filter package sized to each model. The retired series carried a two-stage separator, a timed electric drain and a dew point indicator.
Installing next to the compressor
Keep the pipe run from the compressor head short and give it a drop leg with a drain, because the air is at its wettest between the head and the dryer. Fit a high-temperature particulate filter rated for 450°F at the dryer inlet to stop carbon and scale from the hot cylinders, and put the 0.01 micron oil-removal filter after the dryer where the air is cool enough for its element. Mount the dryer where the condenser draws room air rather than the compressor's discharge, and pipe the drain to a condensate separator; a small piston compressor with no aftercooler makes surprising amounts of water. The reciprocating compressor section sizes the dryer from horsepower.
High inlet temperature dryer questions
Yes, and for a compressor above about 30 hp that is the better answer, because it gets a 38°F dew point and a wider choice of dryers. Below 30 hp an aftercooler, its separator and its drain cost as much as the dryer, so a high-inlet-temperature unit that does both jobs is the simpler purchase.
A 50°F pressure dew point, ISO 8573-1 class 6, at rated flow and rated inlet temperature. Fed cooler air, for example 150°F from a two-stage compressor, they deliver a lower dew point, but they are not rated for class 4 air.
The current 25 to 100 SCFM series is rated for 200°F inlet; the 25 to 125 SCFM direct-expansion series and the retired series are rated for 180°F. Measure the discharge temperature at the dryer inlet on a hot day before choosing; a single-stage compressor at 175 psig can exceed 200°F.
A high-temperature particulate filter rated for the inlet air, not a standard coalescer whose element is limited to 150°F. The direct-expansion series offers a matched 1 micron inlet filter package; the separate high-temperature filter line covers 15 to 1,600 SCFM.
The 200°F series, size for size from 25 to 100 SCFM; the 20 SCFM size is covered by the 25 SCFM model and the 125 SCFM size by the 125 SCFM direct-expansion unit. All are 115 V, so the swap is a piping change at most.
