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California Energy Code 140.4(n) requirement

John shane

Registered User
Joined
Feb 13, 2020
Messages
10
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?
 

mark handler

Sawhorse
Joined
Oct 25, 2009
Messages
11,126
Location
So. CA
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
 

TheCommish

Sawhorse
Joined
Sep 27, 2011
Messages
1,293
Location
Charlton Ma
And the contractors here in MA, think they have it tough when that have to leak test the building and put in radon ventilation
 

Yikes

Gold Member
Joined
Nov 2, 2009
Messages
1,903
Location
Southern California
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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