What CFM Vacuum Pump Do You Need? VEVOR 3.5–9 CFM Guide
HVAC vacuum pumps are often compared by CFM first, but CFM is only part of the decision. This VEVOR family ranges from 3.5 to 9 CFM and includes both single-stage and two-stage rotary-vane designs. The single-stage configurations list a 5 Pa ultimate vacuum, while the two-stage 6 CFM and 9 CFM models list 0.2 Pa. Choosing well means balancing free-air displacement, ultimate vacuum, power, oil capacity, weight, and the type of service work you actually do.
What CFM HVAC vacuum pump do you need?
A higher CFM rating means greater listed free-air displacement, but it does not replace the need to consider final vacuum level and the complete service setup. In this VEVOR family, 3.5–5 CFM single-stage options list a 5 Pa ultimate vacuum, while the 6 and 9 CFM two-stage options list 0.2 Pa. For many buyers, the first decision is therefore not simply “more CFM,” but single-stage vs two-stage.
Compare VEVOR HVAC Vacuum Pumps →Key Takeaways
Higher CFM means greater listed free-air displacement, not automatically a better fit for every job.
The 3.5, 4 and 5 CFM single-stage configurations list a 5 Pa ultimate vacuum.
The 6 and 9 CFM two-stage configurations list a 0.2 Pa ultimate vacuum.
These listed configurations use 1/4" SAE and 1/2" ACME intake fittings.
What Does CFM Mean on an HVAC Vacuum Pump?
CFM stands for cubic feet per minute and, on these models, refers to free-air displacement. Under otherwise comparable conditions, a higher displacement rating can move a larger volume of air per minute during the earlier part of evacuation. Actual evacuation time still depends on the system volume, hose size and length, restrictions, moisture, oil condition, connection quality, and the target vacuum level.
Single-Stage vs Two-Stage Vacuum Pumps
Single-Stage
The listed 3.5, 4 and 5 CFM single-stage VEVOR models use a single-stage rotary-vane design and specify a 5 Pa ultimate vacuum. They are generally lighter than the 9 CFM two-stage model in this family.
Two-Stage
The 6 and 9 CFM models use a two-stage design and specify a deeper 0.2 Pa ultimate vacuum. They also step up in power, weight, or both compared with the smaller single-stage configurations.
VEVOR HVAC Vacuum Pump Comparison
| Configuration | Stage | CFM | Ultimate Vacuum | Power | Oil Capacity |
|---|---|---|---|---|---|
| 3.5 CFM / 1/4 HP | Single | 3.5 | 5 Pa | 180 W or 1/4 HP* | 260 ml |
| 4 CFM / 1/3 HP | Single | 4 | 5 Pa | 150 W | 260 ml |
| 5 CFM / 1/2 HP | Single | 5 | 5 Pa | 250 W | 280 ml |
| 6 CFM / 1/2 HP | Two | 6 | 0.2 Pa | 370 W | 260 ml |
| 9 CFM / 1 HP | Two | 9 | 0.2 Pa | 750 W | 600 ml |
*This family contains two listed 3.5 CFM single-stage SKUs with closely related specifications. Check the selected SKU before ordering. Current availability can change.
How to Choose Between 3.5, 4, 5, 6 and 9 CFM
01 · Decide whether you need single-stage or two-stage
If the specified ultimate vacuum is a major buying requirement, compare 5 Pa single-stage models with the 0.2 Pa two-stage models before comparing CFM alone.
02 · Compare free-air displacement
Choose a displacement level appropriate to the system volume and your workflow. Higher CFM can provide more pumping capacity, but hoses and restrictions can limit real-world performance.
03 · Check weight and portability
The listed 3.5–6 CFM configurations range roughly from 11 to 17 lb, while the 9 CFM two-stage model is listed at 34.61 lb.
04 · Confirm fittings and refrigerant compatibility
These listed models use 1/4" SAE and 1/2" ACME intake fittings and list compatibility with R134a, R22, R410a and other non-flammable refrigerants.
05 · Check current stock for the exact SKU
Not every configuration is always in stock. Use the product selector to confirm current availability before choosing by specification alone.
Common Vacuum Pump Buying Mistakes
- Choosing only by CFM and ignoring ultimate vacuum.
- Assuming every model in the family is two-stage.
- Ignoring pump weight when the tool needs to be carried between jobs.
- Forgetting to confirm intake fittings and hose compatibility.
- Comparing horsepower labels without checking the listed electrical power and exact SKU.
- Ignoring oil capacity, oil condition, and routine maintenance requirements.
Quick Selection Checklist
- I chose single-stage or two-stage based on the required specification.
- I compared CFM with system size and workflow needs.
- I checked ultimate vacuum.
- I checked pump weight and portability.
- I confirmed fittings and refrigerant compatibility.
- I checked current inventory for the exact configuration.
VEVOR HVAC Vacuum Pumps: 3.5–9 CFM
Compare current stock, CFM, single- vs two-stage construction, ultimate vacuum, power, oil capacity, fittings and weight.
View Vacuum Pump Options →Frequently Asked Questions
Specifications and availability vary by SKU. Follow the selected product manual and applicable service procedures.