Mech Exhaust Required in Residential Kitchens

[Gregg Harris]

"I would argue 505 is specific to domestic kitchen exhaust equipment and is more specific than a footnote in a ventilation table"But... footnote b says mechanical ventilation is required in the kitchen. It does not say that the hood must be the ventilation method. In fact it doesn't say anything about hoods.

A ceiling exhaust fan, similar to a bath fan would comply if it was 100 CFM intermittent or 20 CFM constant.

Can someone with the 2009 and 2012 IMC confirm that Kitchens do indeed have footnote b, so I can understand whether this is just an Ohio issue?

Foot note (b) is in both 09 and 12 but you are dealing with 2 different sections.

401.1 Scope.

This chapter shall govern the ventilation of spaces within a building intended to be occupied. Mechanical exhaust systems, including exhaust systems serving clothes dryers and cooking appliances; hazardous exhaust systems; dust, stock and refuse conveyor systems; subslab soil exhaust systems; smoke control systems; energy recovery ventilation systems and other systems specified in Section 502 shall comply with Chapter 5.

401.2 Ventilation required.

Every occupied space shall be ventilated by natural means in accordance with Section 402 or by mechanical means in accordance with Section 403. Where the air infiltration rate in a dwelling unit is less than 5 air changes per hour when tested with a blower door at a pressure of 0.2-inch water column (50 Pa) in accordance with Section 402.4.1.2 of the International Energy Conservation Code, the dwelling unit shall be ventilated by mechanical means in accordance with Section 403.

 

[mtlogcabin]

Where the air infiltration rate in a dwelling unit is less than 5 air changes per hour when tested with a blower door at a pressure of 0.2-inch water column (50 Pa) in accordance with Section 402.4.1.2 of the International Energy Conservation Code, the dwelling unit shall be ventilated by mechanical means in accordance with Section 403.

I see that is new to the 2012 IMC which could make a big change where I live since the state requires 4 ACH max.

I agree the 2012 will require a kitchen exhaust system in a dwelling designed with less than 5 ACH.

The earlier editions do not

Gregg thanks for finding the change

 

[Gregg Harris]

I see that is new to the 2012 IMC which could make a big change where I live since the state requires 4 ACH max. I agree the 2012 will require a kitchen exhaust system in a dwelling designed with less than 5 ACH.

The earlier editions do not

Gregg thanks for finding the change

Vobis sunt grata

delectalio mea

 

[Yikes]

Just confriming: out here in California, our California Mechancial Code is based on the UMC, not the IMC, so for multifamily housing in CA there is no requirement for domestic kitchen range to have a hood that discharges to the outdoors. Corollary: if an apartment happens to happens a domestic range hood that discharges to outdoors, there is no minimum CFM requirement.

Am I correct?

 

[mtlogcabin]

I believe you do

2012 UMC

Chapter 4 has a lot of changes.

402.1.2 requires dwellings to meet Chapter 4 or ASHRAE 62.2

402.2 requires natural ventilation openings to be permanently open or controls to prevent the opening from being closed while occupied

Same as the 2009 UMC

403.7 requires exhaust ventilation

Table 403.7 Residential kitchens requires 50/100 cfm/unit

 

[Gregg Harris]

Local Ventilation Exhaust Requirements [

ASHRAE 62.2

, Section 5]

:

In addition to meeting the Whole-Building Ventilation Requirements discussed in the previous

section,

ASHRAE 62.2

requires that

each

kitchen and bathroom have a local ventilation exhaust

system installed that exhausts indoor air to outside the dwelling. The Local Ventilation Exhaust

Requirements in one room can be met by a Whole-Building Ventilation exhaust system installed

in that room (in this case Local Ventilation

Exhaust systems would still have to be installed in

other kitchens and bathrooms where the Whole-Building Ventilation exhaust system is not

installed.) Use of operable windows is not allowed for meeting the local ventilation exhaust.

 

[Yikes]

I agree that 2009 UMC (2010 CBC) table 4-1 requires ventilation air for the apartment unit. My mechanical engineer uses a continuous running bathroom fan* (and undercuts in the doors) to achieve this.

That said, I do not see anythign that would ADDITIONALLY require kitchen-specific exhaust. Table 4-4 has exhaust requirements for "Kitchen-commercial" and "Kitchenettes". I don't know what the code defintion of a "kitchenette" is, but it doesn't sound like an apartment unit kitchen.

As the OP said, on multifamily housing we are getting squeezed between the requirements of the code to provide exhaust to the outside (and makeup air), vs. the city planning requirements to try and avoid wall-mounted louvers. On my last project I tried to use a subduct system with roof-mounted exhaust, but the requirement for continuous power meant we had to add a generator to the project.