Nadair ST-700-35H Hybrid Central Vacuum Power Unit, 700 AW, 35L

Quick Summary

The Nadair ST-700-35H is a 700-airwatt central vacuum power unit with a 35 L / 9.25 gal bottom-load canister, 141.2 inches of water lift and 140.2 CFM of airflow. Its hybrid filtration system lets you operate with a disposable bag or with the included washable permanent filter for bagless operation.

Authorized Nadair Dealer Ace Vacuums can help you evaluate this whole-house vacuum for an existing central vacuum piping network, including the piping run and the hose connection requirements. The unit has a 63 dB noise level, top air intake, rolled steel construction and a 10-year residential-use warranty with one year of labor coverage.

Quick Highlights

• 700 airwatts with a 5.7-inch, two-stage Ametek thru-flow motor
• 141.2 inches of water lift and 140.2 CFM of airflow
• 35 L / 9.25 gal bottom-load rolled steel canister
• 63 dB operation with foam isolation and an integrated muffler
• 10-year warranty on specified parts, with one year of labor coverage

Product Overview

The Nadair ST-700-35H is designed as a central vacuum system for homes with existing or new central vacuum piping. Its 700 airwatts, 141.2 inches of water lift and 140.2 CFM provide the core suction and airflow specifications for a full central vacuum installation, while the bottom-load canister makes debris removal practical wherever the unit is mounted.

This model uses hybrid cyclonic filtration, so homeowners can choose between a triple-layer disposable filtration bag and bagless operation with the included permanent machine-washable filter. Nadair states that the filtration system filters up to 99.97%. The permanent filter must remain installed at all times, including when a disposable bag is being used.

The 35 L / 9.25 gal canister is the larger-capacity option compared with the ST-700-25H, while retaining the same 700 airwatts, 141.2 inches of water lift, 140.2 CFM airflow and 63 dB noise specification. Its rolled steel canister is intended to resist wear, corrosion and damage, and the top air intake is designed for connection to an existing piping network.

The ST-700-35H is a power unit only. A hose and attachment kit are sold separately and must match the home's inlets, including whether the installation uses low-voltage or electric hose controls. Ace Vacuums can help size the unit for the home's piping run and help identify compatible accessories.

Expert Recommendation

This model suits homeowners who want a high-capacity hybrid central vacuum power unit without moving to Nadair's Heavy Duty or Super Duty lines. The 35 L canister is useful when a larger debris container is preferred, and the choice of bagged or bagless operation gives the homeowner flexibility in how the system is maintained.

The ST-700-25H is a better fit when the same 700-airwatt performance is wanted in a smaller 25 L / 6.6 gal canister. A Heavy Duty model such as the HD-750-32H is a better fit for shoppers who specifically want 750 airwatts, 146 inches of water lift and soft start/stop, while a Super Duty model is the relevant comparison for shoppers seeking self-cleaning cyclonic filtration.

The unit requires proper central vacuum installation, low-voltage control wiring for a hose on-off switch and a suitable protected location. It is not a portable vacuum and does not include the hose or cleaning tools needed to use the home's inlets.

Best For

Larger Canister Preference

The 35 L / 9.25 gal bottom-load canister provides more capacity than the ST-700-25H's 25 L / 6.6 gal canister while keeping the same 700-airwatt performance.

Flexible Filtration

Hybrid cyclonic filtration allows operation with the included triple-layer disposable bag or with the included permanent washable filter for bagless use.

Existing Piping Networks

The top air intake is designed to connect to an existing central vacuum piping network using standard 2-inch outside-diameter PVC piping that meets ASTM F2158.

Noise-Conscious Homes

The 63 dB specification is supported by double noise isolation, including noise-isolating foam and an integrated muffler.

Long-Term Ownership

The rolled steel canister is resistant to wear, corrosion and damage, and the specified motor, electronic module, body, housing and dust canister parts have a 10-year residential-use warranty.

Bagged or Bagless Households

Homeowners can choose the convenience of disposable bags or use the permanent washable filter for bagless operation, provided the filter remains installed.

Not Ideal For

• It may not be the right choice for shoppers who want soft start/stop, since that feature is listed for the Heavy Duty and Super Duty comparison models rather than this ST-700-35H.
• The unit requires installation in a suitable location with central vacuum piping and low-voltage wiring for the hose on-off switch; it is not a standalone portable vacuum.
• A hose and attachment kit are not included, so the homeowner must purchase accessories that match the home's low-voltage or electric inlets.
• The larger 35 L canister may require more installation space than the ST-700-25H's 25 L canister, even though both models have the same listed height and similar overall dimensions.

Key Features

• 700 Airwatts: The two-stage Ametek thru-flow motor is rated at 700 airwatts.
• Strong Airflow: The system provides 141.2 inches of water lift and 140.2 CFM of airflow.
• Hybrid Filtration: Use a disposable bag or the included permanent washable filter for bagless operation.
• Large Canister: The bottom-load canister holds 35 L / 9.25 gal and is easy to remove where installed.
• Noise Isolation: Noise-isolating foam and an integrated muffler support the listed 63 dB noise level.
• Rolled Steel Body: The rolled steel canister is resistant to wear, corrosion and damage.
• Top Air Intake: The top intake is designed to connect with an existing central vacuum piping network.
• Status LED: An LED indicator displays the status of the power unit.
• Long Warranty: The residential-use warranty covers specified parts for 10 years and includes one year of labor.

What Makes This Model Stand Out

The main distinction of the ST-700-35H is its combination of 700-airwatt performance and a 35 L / 9.25 gal canister. It matches the ST-700-25H in motor output, water lift, airflow and noise level, but provides the larger canister size for homeowners who prefer greater capacity.

Its hybrid design also avoids forcing a single maintenance approach. The included disposable bag offers a contained debris-removal option, while bagless operation is available with the permanent filter. In either configuration, the permanent filter must remain installed and must be washed with cold water when the canister is emptied.

Product Comparisons

ST-700-35H vs ST-700-25H

Both models provide 700 airwatts, 141.2 inches of water lift, 140.2 CFM of airflow, 63 dB operation and hybrid filtration with or without a disposable bag. The ST-700-35H has a 35 L / 9.25 gal canister, while the ST-700-25H has a 25 L / 6.6 gal canister.

ST-700-35H vs HD-750-32H

The ST-700-35H is rated at 700 airwatts, 141.2 inches of water lift, 140.2 CFM and 63 dB, with a 35 L / 9.25 gal canister. The HD-750-32H lists 750 airwatts, 146 inches of water lift, 141.2 CFM and 65 dB, with a 32 L / 8.45 gal canister and soft start/stop.

Central Vacuum vs Portable Vacuum

A central vacuum power unit stays in a garage or basement instead of requiring the homeowner to carry a heavy machine from room to room. Its exhaust can be vented outside when the installation is designed for that, but it requires installed piping, a hose and compatible cleaning tools.

Bagged vs Hybrid Operation

Bagged operation uses a disposable triple-layer bag, while hybrid operation can use the permanent washable filter without a disposable bag. The permanent filter must stay installed in both modes, and it should be washed with cold water whenever the canister is emptied.

Questions Buyers Commonly Ask

Can this unit connect to my existing central vacuum piping?

The ST-700-35H is designed for an existing piping network and fits standard 2-inch outside-diameter PVC piping meeting ASTM F2158. Ace Vacuums can help check the piping run and accessory compatibility before installation.

Do I have to use disposable bags?

No. This is a hybrid system that can be used with the included triple-layer disposable bag or in bagless operation with the included permanent washable filter. The permanent filter must remain installed at all times.

Is the 35 L canister the main reason to choose this model?

It is a key difference from the ST-700-25H, which has a 25 L / 6.6 gal canister. Both models list the same 700 airwatts, water lift, airflow and noise level.

Does the unit include a hose and cleaning tools?

No. The hose and attachment kit are sold separately and must match the home's inlets. Check whether the system uses low-voltage or electric hose controls before selecting accessories.

Can the exhaust be vented outside?

Outdoor venting is recommended by the manual. The exhaust should not point at a wall or ceiling or discharge into a closed space.

Technical Specifications

Installation Notes

• Install the unit in a well-ventilated, weather-protected location away from heat; it must not be installed outdoors.
• Allow at least 6 inches / 15 cm of clearance around the power unit.
• Have a certified central vacuum installer complete the installation. The included wall bracket is packed in the foam.
• The unit uses a 110-120 VAC, 60 Hz, 15 A circuit. Its own circuit is recommended but not required; do not use an extension cord or adapter.
• Use the 72-inch / 1.83 m grounded power cord and connect the low-voltage wire needed for the hose on-off switch.
• Connect the top air intake to compatible standard 2-inch outside-diameter PVC piping. Outdoor exhaust venting is recommended, and the exhaust should not point at a wall or ceiling or into a closed space.

Maintenance Tips

• Empty the canister or replace the disposable bag three or four times per year, as indicated by the manual and household use.
• If using a disposable bag, use the FD-22.5L-3NAD replacement bag. Bags are sold in packs of three.
• Keep the FP-12 permanent filter installed at all times, including when using a disposable bag.
• Wash the permanent filter with cold water each time the canister is emptied, and replace it every year to keep the warranty.
• Use the LED indicator and the condition of the canister or bag to help monitor the unit between maintenance intervals.

Ideal Buyers

Perfect for:

• Homeowners who want a 700-airwatt central vacuum power unit with a larger 35 L canister.
• Households that want the choice of disposable-bag or bagless operation.
• People replacing a compatible central vacuum power unit on an existing standard 2-inch PVC piping network.
• Homeowners who value a rolled steel canister and a 10-year residential-use parts warranty.
• Buyers who want a 63 dB unit with noise-isolating foam and an integrated muffler.

Why Buy from Ace Vacuums

When you purchase from Authorized Nadair Dealer Ace Vacuums, you receive:

• Genuine Nadair central vacuum power units
• Expert help sizing the right unit for your home and piping
• Guidance on matching hoses and attachment kits to your inlets
• Genuine Nadair replacement bags and filters
• Knowledgeable customer support before and after the sale

Available Online & In-Store

The Nadair ST-700-35H is available online and in-store through Authorized Nadair Dealer Ace Vacuums.

Visit Our Showrooms

• Fairfax, VA: 11110 Main St, Fairfax, VA 22030
• Leesburg, VA: 300 Fort Evans Rd NE, Leesburg, VA 20176

Call 703-997-9292 (ext. 1 Fairfax, ext. 2 Leesburg). Both stores are open 7 days a week to compare central vacuum systems and talk with our specialists.

Comparison Table

Pros and Cons

Pros

• 700 airwatts with 141.2 inches of water lift and 140.2 CFM of airflow.
• 35 L / 9.25 gal bottom-load canister provides more capacity than the ST-700-25H.
• Hybrid filtration supports disposable-bag or bagless operation.
• 63 dB noise level with foam isolation and an integrated muffler.
• Rolled steel canister is resistant to wear, corrosion and damage.
• 10-year warranty on specified parts with one year of labor for residential use.

Cons

• A hose and attachment kit are sold separately.
• The unit requires compatible central vacuum piping, low-voltage wiring and proper installation.
• Disposable bags are an ongoing accessory cost for homeowners who prefer bagged operation.
• The larger canister may require more room than the ST-700-25H's 25 L canister.

Frequently Asked Questions

What kind of product is the Nadair ST-700-35H?

It is a central vacuum power unit for a whole-house vacuum installation. The power unit connects to the home's central vacuum piping and works with a separately purchased hose and cleaning kit.

How powerful is the ST-700-35H?

The motor is rated at 700 airwatts. Nadair lists 141.2 inches of water lift and 140.2 CFM of airflow.

How large is the dirt canister?

The bottom-load rolled steel canister holds 35 L / 9.25 gal. It is larger than the ST-700-25H's 25 L / 6.6 gal canister.

Can I use the system without a disposable bag?

Yes. The hybrid filtration system supports bagless operation with the included permanent washable filter. The permanent filter must still remain installed.

What bag fits this model?

The specified replacement bag is the FD-22.5L-3NAD bag. The unit includes one triple-layer disposable filtration bag, and replacement bags are sold in packs of three.

What filter fits this model?

The specified permanent replacement filter is the FP-12. One permanent machine-washable filter is included with the power unit.

How do I clean the permanent filter?

Wash it with cold water each time the canister is emptied. It must remain installed at all times and should be replaced every year to keep the warranty.

How often should I empty the canister or replace the bag?

The manual says to replace the bag or empty the canister three or four times per year. Actual timing depends on household use and the amount of debris collected.

What is the noise level?

The listed noise level is 63 dB. Noise-isolating foam and an integrated muffler provide the stated double noise isolation.

Does it work with standard existing piping?

The product is designed for standard 2-inch outside-diameter PVC piping meeting ASTM F2158. A qualified installer should verify the existing piping and the complete piping run.

What electrical connection does it need?

The manual specifies 110-120 VAC, 60 Hz and a 15 A circuit. A dedicated circuit is recommended but not required, and extension cords or adapters should not be used.

Is a power cord included?

Yes. The unit has a 72-inch / 1.83 m grounded power cord.

Does the package include a hose?

No. The hose and attachment kit are sold separately. Accessories must match the home's inlets and the low-voltage or electric control arrangement.

Where should the power unit be installed?

Install it in a well-ventilated, weather-protected area away from heat, with at least 6 inches / 15 cm of clearance on all sides. It should not be installed outdoors.

Can the exhaust be vented outdoors?

Outdoor venting is recommended. The exhaust should not point at a wall or ceiling or discharge into a closed space.

What warranty comes with the unit?

The warranty is 10 years on the motor, electronic module, body, housing and dust canister while you own it, with one year of labor. The warranty is for residential use only.

How does this compare with the ST-700-25H?

Both models list 700 airwatts, 141.2 inches of water lift, 140.2 CFM and 63 dB. The ST-700-35H has the larger 35 L / 9.25 gal canister, while the ST-700-25H has a 25 L / 6.6 gal canister.