QuietScore › Bathroom & Utility Fans › Delta 70BT
Delta 70BT noise level
The Delta 70BT is louder than the category median of 0.7 sones, and its 70 CFM rating makes it suitable for bathrooms up to roughly 70 sq ft. It also meets the stricter ENERGY STAR “Most Efficient” criteria for its category.
Full specifications
| Brand | Delta |
|---|---|
| Model number | 70BT |
| Model name | BreezSlim |
| Category | Bathroom & Utility Fans |
| Sound level | 1 sone (≈40 dBA, approximate) |
| Airflow | 70 CFM |
| Efficiency | 10.6 CFM/W |
| Duct size | 4 inch diameter |
| Speeds | 1 |
| Integrated lighting | No |
| ENERGY STAR certified | Yes — Most Efficient |
| On market since | 2016-07-29 |
| Markets | United States, Canada |
Quieter alternatives with similar airflow
| Model | Sones | ≈ dBA | Airflow | Efficiency | |
|---|---|---|---|---|---|
| Greenheck SP-A70 | 0.1 | 7 | 70 CFM | 5.1 CFM/W | specs |
| Broan XB80=XB00HwithXB80F | 0.1 | 7 | 80 CFM | 13.8 CFM/W | specs |
| Greenheck SP-A90L | 0.1 | 7 | 99 CFM | 6.1 CFM/W | specs |
| AUPU BF4-S10CL | 0.1 | 7 | 100 CFM | 9.5 CFM/W | specs |
| Greenheck SP-LP0810W | 0.1 | 7 | 100 CFM | 10 CFM/W | specs |
Similar bathroom & utility fans
| Model | Sones | ≈ dBA | Airflow | Efficiency | |
|---|---|---|---|---|---|
| Nektra 33003851 | 1 | 40 | 70 CFM | 3.4 CFM/W | specs |
| Delta ITG70BT ME | 1 | 40 | 70 CFM | 10.6 CFM/W | specs |
| HomeWerks Worldwide 7105-10 | 1 | 40 | 70 CFM | 3.4 CFM/W | specs |
| HomeWerks Worldwide 7105-10-MB | 1 | 40 | 70 CFM | 3.4 CFM/W | specs |
| Tuscany 7105-11-M | 1 | 40 | 70 CFM | 3.4 CFM/W | specs |
Frequently asked questions
How many sones is the Delta 70BT?
The Delta 70BT is certified at 1 sone in ENERGY STAR lab testing, which is approximately 40 dBA. That is comparable to a quiet modern refrigerator humming in the next room.
Is the Delta 70BT quiet?
At 1 sone, the Delta 70BT is quieter than 30% of the 811 certified bathroom & utility fans we track, and louder than the category median of 0.7 sones.
How powerful is the Delta 70BT?
It moves 70 CFM, which is adequate for a bathroom of roughly 70 sq ft under the standard 1-CFM-per-square-foot guideline, at an efficiency of 10.6 CFM per watt.
Data provenance: Sound levels are certified lab measurements (sones) reported in the U.S. EPA ENERGY STAR certified products dataset — not manufacturer marketing claims. Source: ENERGY STAR Certified Ventilating Fans (US EPA), last fetched 2026-06-13. The dBA figure is an approximate conversion from sones — see our methodology.