2012 IRC & IMC Defined
2012 IRC Ventilation Requirements and S&P Solutions
The Ventilation Requirements of the IRC are found in Chapter 15: Exhaust Systems. We have provided a brief overview of each section requiring ventilation (for the full code visit www.iccsafe.org):
Section M1502: Clothes Dryer Exhaust
The Code Specifies:
- The dryer exhaust MUST terminate to the outside
- The MAX. length of the [dryer] exhaust duct is 35 feet from the connection of the outlet terminal
Problem Created by Code:
- What if the dryer is NOT located close to the outlet terminal?
- What if the duct is longer than 35 feet so elbows are necessary creating complicated duct work? (ref. table 1502.4.4.1)
FACT: When ducting from a dryer to the outlet is long and/or complicated the dryer cannot overcome the static pressure thus reducing efficiency and causing increased or poor drying time.
S&P's Recommended Solution:
- A Clothes Dryer Booster Fan will help overcome the static pressure created from long and/or complicated duct runs.
PV100X with Current Sensor
Section M1503: Range Hoods
The Code Specifies:
- Makeup air is required when system is capable of exhausting 400+ CFM
- The rate of makeup air must be (approx.) equal to the exhaust air
S&P's Recommended Solution:
GOOD:
TD-MIXVENT
BEST:
TD-Silent
Section M1507: Mechanical Ventilation
The Code Specifies:
- Whole-house ventilation AND Local Exhaust is required.
Note: There is a common misconception that either Whole-house OR Local Exhaust is required. The IRC 2012 requires that both requirements be met. The Local Exhaust fans do count towards meeting the Whole-house requirement. - Bathroom and toilet air must be exhausted directly to the outdoors and shall not be recirculated within the residence
Whole-house Ventilation Requirements:
- One or more supply or exhaust fans, plus associated ducts and controls
- Local exhaust or supply fans contribute to the whole-house ventilation requirement
- System must have controls that enable manual override
- Outdoor (makeup) air must be provided at a continuous rate (ref. table 1507.3.3)
Exception: if you use controls that enable operation for at least 25% of each 4 hour segment you can operate intermittently.
Floor Area (sq. ft.) | # Bedrooms & Required CFM | ||||
0-1 | 2-3 | 4-5 | 6-7 | > 7 | |
< 1500 | 30 | 45 | 60 | 75 | 90 |
1501-3000 | 45 | 60 | 75 | 90 | 105 |
3001-4500 | 60 | 75 | 90 | 105 | 120 |
4501-6000 | 75 | 90 | 105 | 120 | 135 |
6001-7500 | 90 | 105 | 120 | 135 | 150 |
> 7500 | 105 | 120 | 135 | 150 | 165 |
S&P's Recommended Solutions (Whole-house):
GOOD:
PC-Premium CHOICE Fan (Exhaust)
GOOD:
TD-MIXVENT (Supply)
BETTER:
2 TD-SILENT (Exhaust & Supply)
Local Exhaust Ventilation Requirements:
- Exhaust the minimum air flow rate based on Table 1507.4:
Area to be exhausted | Exhaust Rates |
Kitchens | 100 CFM intermittent or 5 ACH continuous (based on kitchen volume) |
Bathrooms | 50 CFM intermittent or 20 CFM continuous |
S&P's Recommended Solution (Local Exhaust):
GOOD:
PC-Premium CHOICE Fan
BEST:
TD-MIXVENT
2012 IMC Ventilation Requirements and S&P Solutions
The following sections of the IMC 2012 require ventilations:
- Section 403.1: Ventilation System
- Section 403.2: Outdoor Air Required
- Section 403.3: Min Air Flow Rates
- Section 403.4: Exhaust Ventilation
- Section 403.6: Variable Air Volume System Control
- Section 403.7: Balancing
All IRC 2012 Residential Solutions can be used as IMC 2012 Commercial Solutions!
Section 403.1: Ventilation System
The Code Specifies:
- Supply and Return (Exhaust) Air is required
- Supply Air must equal amount of Exhaust Air
Section 403.2: Outdoor Air Required
The Code Specifies:
- Minimum airflow rate determined by Section 403.3
- Must deliver required rate of outdoor airflow to the BREATHING ZONE within each OCCUPIABLE SPACE
Section 403.4: Exhaust Ventilation
The Code Specifies:
- Exhaust airflow rate determined by Section 403.3
- Exhaust makeup air can be combination of outdoor air, recirculated air and transfer (except as limited by Section 403.2)
Section 404.6: Variable Air Volume System Control
The Code Specifies:
- Controls required to regulate the flow of outdoor air
- Control system must be designed to maintain the outdoor airflow rate required by Section 403.3
S&P's Recommended Control Solutions:
- FT622 or FT247 Controls
- Designed exclusively for TD-100, TD-100X1 and TD-150 to allow the fans to run continuously at a low rate
Note: All summaries and solutions recommended by S&P are the most common situations and in our opinion the best solutions to meet the standards. Please refer to the entire IRC or IMC 2012 Standards and your local code to ensure you are meeting all requirements.