Altec AIR HR4 — 12 SCFM Inlet Heatless Desiccant Air Dryer

Made in the USA. The Altec AIR HR4 provides ultra-dry compressed air for smaller compressed air systems and point-of-use applications requiring a -40°F pressure dew point. Its twin-tower heatless regenerative design dries air in one tower while regenerating the other, helping protect moisture-sensitive pneumatic equipment, instrumentation, and processes.

Size for delivered air: the HR4 is rated for 12 SCFM inlet flow and delivers 8.8 SCFM usable outlet flow after 3.2 SCFM of regeneration purge at 100 PSIG. Confirm the required outlet flow and actual operating conditions before selecting your dryer.

Key Features

• Made in the USA — Altec AIR heatless desiccant drying.
• 12 SCFM inlet / 8.8 SCFM outlet at the standard 100-PSIG rating.
• -40°F/-40°C standard pressure dew point — ISO 8573-1 Class 2 for water.
• Spring-loaded desiccant beds help extend desiccant life.
• Fully re-pressurizing design supports steady outlet pressure and airflow.
• NEMA 4X electrical rating and compact design with versatile mounting options.
• 3/8" NPT inlet and outlet connections.
• Selectable moisture indicator and tower pressure gauges let you configure monitoring accessories.

Overview & Sizing

Choose the HR4 when your application requires a lower pressure dew point than a refrigerated dryer can provide. Match the dryer to the air demand at the point of use and account for purge consumption when checking compressor capacity. Air entering the dryer must be cooled and properly filtered; this dryer is not a substitute for upstream condensate removal.

The 12 SCFM inlet rating is based on 100 PSIG inlet pressure and 100°F inlet temperature. For other inlet pressures, apply Altec's inlet-flow factor and purge-flow factor separately, then subtract calculated purge from calculated inlet flow. A -100°F/-73°C requirement needs a different capacity factor. Call 877.247.2381 for sizing help.

Compare another size: Altec AIR HR5 Heatless Desiccant Air Dryer – 16 SCFM.

Technical Specifications

Choose Your Configuration

• Voltage: HR4-11 is the factory 120-VAC model, shown as 115V/1Ph in the current selector. HR4-21 is the factory 240-VAC model, shown as 230V/1Ph. Confirm supply compatibility against the factory nameplate.
• Moisture indicator: select Yes to add the optional visual moisture indicator; identified by M in the website SKU.
• Tower pressure gauges: select Yes to add the optional gauges; identified by PG in the website SKU (Altec's factory option code is P).

Recommended Filtration & Accessories

Filter kits are sold separately. Use properly sized inlet coalescing filtration to help protect the desiccant and an outlet particulate filter to capture desiccant dust. Choose from these matched Altec AIR filter kits:

• AD11-HR14 — Recommended two-filter kit: one XA-grade 0.01-micron coalescing pre-filter and one X1-grade 1-micron particulate after-filter; 3/8" NPT.
• AD21-HR14 — Three-filter upgrade: adds an X5-grade 5-micron coalescing pre-filter ahead of the 0.01-micron pre-filter and 1-micron after-filter; 3/8" NPT.
• AD11-HR14-R / AD21-HR14-R: corresponding kits with outlet regulator and gauge.
• Optional floor stand: available separately. The 175-PSIG V1 option is not available for HR1–HR4.

Contact Compressed Air Advisors Online to add the matched filter kit or request a special configuration. Filter flow ratings do not increase dryer capacity.

What's Included

• Altec AIR HR4 heatless desiccant air dryer in the selected AC voltage configuration.
• Moisture indicator and tower pressure gauges only when selected as Yes.

Filter kits, regulator kits, floor stands, piping, and installation materials are sold separately. A -100°F dew point, DC power, or other special configuration must be quoted separately.

Lead Time

Contact us for current factory availability and an estimated ship date if your project has a required delivery date.

Frequently Asked Questions

How much usable dry air does the HR4 deliver?

At 100 PSIG and the standard -40°F pressure dew point rating, inlet capacity is 12 SCFM, purge consumption is 3.2 SCFM, and usable outlet flow is 8.8 SCFM. Size for your required outlet flow plus purge demand; the 12 SCFM headline is inlet capacity.

What dew point does this dryer provide?

Standard performance is a -40°F/-40°C pressure dew point, corresponding to ISO 8573-1 Class 2 for water. This is a moisture classification, not a complete oil and particle purity rating. A -100°F/-73°C configuration is available by request and requires revised sizing.

Does this dryer use compressed air for regeneration?

Yes. The twin-tower heatless design uses a portion of dried compressed air to regenerate the off-line desiccant bed. Published purge consumption is 3.2 SCFM at 100 PSIG.

Which electrical option should I choose?

Altec lists HR4-11 as 120 VAC and HR4-21 as 240 VAC, single-phase, 60 Hz. The current website selectors label these 115V/1Ph and 230V/1Ph respectively. Confirm your electrical supply and the selected factory model/nameplate before ordering. DC models are available by request.

Are moisture indicators and pressure gauges included?

They are optional. Select Yes for the moisture indicator and/or tower pressure gauges to include those accessories. A base configuration with both set to No does not include either option.

Which filters should I use?

Altec AIR recommends AD11-HR14: one 0.01-micron coalescing pre-filter and one 1-micron particulate after-filter. AD21-HR14 adds a 5-micron coalescing pre-filter. Kits are sold separately; an -R kit adds an outlet regulator and gauge.

Can I operate this dryer above 150 PSIG?

No. The listed standard configuration is rated to 150 PSIG maximum. The V1 175-PSIG option is not available for HR1–HR4.

How do pressure and temperature affect selection?

The standard rating is based on 100 PSIG inlet pressure, 100°F inlet temperature, and a -40°F pressure dew point. Use Altec's pressure correction factors for other pressures, calculate purge separately, and subtract purge from corrected inlet capacity. Maximum inlet temperature is 120°F; that limit is not the full-capacity rating condition.

Why Buy From Compressed Air Advisors Online?

Get expert help selecting the dryer, filtration, and accessories for your actual airflow, pressure, and dew point requirements. Our team supports customers nationwide. Call 877.247.2381 before ordering if you need help choosing a configuration.

Shipping & Returns

Free shipping within the contiguous United States. Contact us for special delivery requirements.

Eligible returns require an RMA within 14 days and must be new and unused. A 25% restocking fee applies, and the customer pays return freight. Electrical items and built-to-order equipment are non-returnable. Return eligibility is subject to our return policy.