Window ACs, Wall-Sleeve Units and Portable Heat Pumps: Title 24?
The Energy Code excepts room air conditioners and room air-conditioner heat pumps from several controls, such as the setback thermostat rule, and takes their efficiency from the appliance regulations. Whether installing one needs a permit is the building department's decision, and a unit sized to condition a garage or porch can change that space's status.
- Choose your report
- Upload your plans
- Pay securely
- Permit-ready report by email
What the Standards actually say about room units
Part 6 names room air conditioners and room air-conditioner heat pumps in four exceptions:
- Both are excepted from the setback thermostat requirement (Exception to Section 110.2(c)).
- Room air-conditioner heat pumps are excepted from the supplementary-heater controls (Exception 2 to Sections 110.2(b) and 150.0(h)7).
- They are excepted from the heat pump thermostat requirements, which include an outdoor temperature display and a lockout above 35 degrees F (Exception 2 to Section 150.0(i)2).
Those carve-outs recognize a product that has no central thermostat or ducts. They do not say that a room unit is outside the code altogether.
Efficiency comes from the appliance rules
Part 6 sets no efficiency tiers of its own for room units; the appliance rules do. Room air conditioners are certified to the Energy Commission under the Appliance Efficiency Regulations and rated in combined energy efficiency ratio (CEER), while central equipment uses SEER2 and EER2. An appliance regulated by those rules may be installed only if it complies (Section 110.1). A shopper can confirm a model in the Commission's appliance database.
The capacity test
"Directly conditioned space" is defined by capacity: wood heating, mechanical heating above 10 Btu/hr per square foot, or mechanical cooling above 5 Btu/hr per square foot (Section 100.1(b)). The definition looks at capacity, not at whether a unit is plug-in. That matters because a space converted from unconditioned to conditioned is newly conditioned space, which must comply as an addition. A unit cooling a garage, shed or porch for living use is the case to raise with the department first.
Permits and replacements
Replacing equipment the Standards regulate is an alteration, not a repair, and the Commission lists newly installed mini-split systems among alterations covered by the code. Whether a plug-in window unit needs a permit is a local question, so ask the building department. Hardwired and ducted systems follow the mini-split checklist.
Related: repair versus alteration, mini-splits in an ADU and HVAC under Title 24. A residential report covers permanent systems.
Common Title 24 Questions
- When is Title 24 required for a home?
- Does a remodel need Title 24?
- Does a room addition need Title 24?
- What plans are needed for a residential Title 24 report?
- How much does a residential Title 24 report cost?
- How long does a residential Title 24 report take?
Frequently Asked Questions
Part 6 has no rule written for plug-in room units beyond the exceptions above, and permits are decided locally, so ask the building department. A permanent system or a space conversion is a different case.
In CEER, certified to the Energy Commission by the manufacturer under the Appliance Efficiency Regulations, and visible in the Commission's appliance database.
Explore Air Conditioners
- Does Replacing an AC Coil or Compressor Trigger Title 24?
- Adding Air Conditioning to an Existing House: Title 24 Requirements
- Does Adding Central Air Need Title 24?
- Air Conditioner Replacement Title 24 Checklist
- Can You Install Electric Baseboard or Wall Heaters Under Title 24?
View all Air Conditioners guides → · HVAC and Water Heating · Title 24 guide