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California Energy Code 140.4(n) requirement

John shane

Registered User
Joined
Feb 13, 2020
Messages
12
Location
California
Hi, what is the usual workaround on a building with windows that have no autmatic closer which is required by code to have HVAC window interlocks. The HVAC system will be a new mini split LG, I ask the manufacturer but they can only provide a dry contact in the unit which can shut it off at a signal. The signal can be given by a door sensor contact but how do I delay the receipt of the signal by 5 minutes? Or is there any other workaround in this?
 
SECTION 140.4 – PRESCRIPTIVE REQUIREMENTS FOR SPACE CONDITIONING SYSTEMS
subsection (n) Mechanical System Shut-off.
Any directly conditioned space with operable wall or roof openings to the outdoors shall be provided with interlock controls that disable or reset the temperature setpoint to 55°F for mechanical heating and disable or reset the temperature setpoint to 90°F for mechanical cooling to that space when any such opening is open for more than 5 minutes.

EXCEPTION 1 to Section 140.4(n): Interlocks are not required on doors with automatic closing devices.
EXCEPTION 2 to Section 140.4(n): Any space without a thermostatic control (thermostat or a space temperature sensor used to control heating or cooling to the space).
EXCEPTION 3 to Section 140.4(n): Healthcare facilities.
EXCEPTION 4 to Section 140.4(n): High-rise residential dwelling units.

Building Energy Efficiency Standards - Title 24
Toll-free in California: 800-772-3300
Outside California: 916-654-5106
title24@energy.ca.gov
 
And the contractors here in MA, think they have it tough when that have to leak test the building and put in radon ventilation
 
A couple of clarifications:
The interlock requirement is for a (1) prescriptive compliance approach to (2) "Nonresidential, High-Rise Residential and Hotel/Motel Occupancies".

That's why almost everyone I know pays for a Title 24 consultant to do a performance approach. You spend a little more on design services doing performance instead of prescriptive, but save it in the construction.

See https://up.codes/viewer/california/ca-energy-code-2019/chapter/5/nonresidential-high-rise-residential-and-hotel-motel-occupancies-performance-and#140.1
 
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