Title 24 Pool and Spa Requirements
Pools and spas are regulated as equipment: §110.4 covers the heater, cover, inlets and time switch and, under §110.4(c), how the heating is sized, which unless an exception applies means solar collectors covering at least 60 per cent of the water surface, a heat pump pool heater as the primary heater, or another listed option. Section 150.0(p) adds the pump, piping, filter and valve rules for homes.
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The heater
Under §110.4(a) a pool or spa heater may be installed only if its manufacturer certifies three things: it meets the appliance efficiency standards that apply to it, it has a readily accessible on-off switch on the outside of the heater so it can be shut off without touching the thermostat setting, and it carries a permanent, weatherproof plate or card with its efficiency rating and operating instructions. Section 110.5 adds that natural gas pool and spa heaters may not have a continuously burning pilot light.
Table 110.4-A names the test standard for each heat source: UL 1261 for electric resistance, ANSI Z21.56/CSA 4.7a for gas, AHRI 1160 plus a safety standard for heat pumps, and ICC/APSP 902/SRCC 400 for solar pool heaters.
How the heating must be sized
Section 110.4(c) is the provision that shapes the design. For a single-family home the heating has to be one of:
- solar pool heating with collector area of at least 60 per cent of the pool or spa surface area
- a heat pump pool heater as the primary heater, sized under Reference Joint Appendix JA16.3, with a supplementary heater of any fuel
- a system taking at least 60 per cent of its annual heating energy from on-site renewable or recovered energy
- solar combined with a heat pump pool heater and no other supplementary heater
The compliance manual works an example: a 288 square foot pool with a gas heater backing up solar needs at least 172.8 square feet of collectors. It adds that roof area with less than 70 per cent annual solar access may not be suitable, so where the collectors go is part of the pool design. Where a heat pump pool heater has a supplementary heater, §110.4(d) requires controls that keep the backup off whenever the heat pump alone can carry the load.
Exceptions to the sizing rule
Five cases are exempt from §110.4(c): portable electric spas that meet the Title 20 appliance regulations; alterations to existing pools and spas that already have heating; pools and spas heated only by solar, with no backup; heaters used only for permanent spas in existing buildings with gas available; and permanent spa heaters where there is not enough solar access roof area for a solar system. A portable spa still has to meet Title 20’s efficiency and cover requirements.
Covers, inlets, timers and future solar
- An outdoor pool or spa with gas or electric heating must be installed with a cover.
- Every pool or spa system leaves room for solar: at least 18 inches of pipe between the filter and heater, dedicated suction and return lines, or built-in connections.
- A pool needs directional inlets that mix the water and a permanently installed time switch, so pumps can run off-peak and only as long as water quality requires.
Pumps and plumbing at a home
Section 150.0(p) sets the hydraulic rules. The dedicated-purpose pool pump must be listed in the Energy Commission’s directory of certified equipment, and filtration flow may not exceed the rate that turns the pool over in 6 hours or 36 gpm, whichever is greater. A multi-speed pump defaults to the filtration rate within 24 hours, with an override for servicing. The piping needs at least 4 pipe diameters of straight pipe before the pump, water velocity no higher than 8 feet per second in the return and 6 in the suction, and sweep elbows. Filters are sized to NSF/ANSI 50, and backwash valves are at least 2 inches or the return pipe diameter.
Paperwork
The compliance manual’s list of certificates of compliance has no pool-specific form; pool and spa heating is recorded by the installer on CF2R-PLB-03-E. The building department decides what it wants with the permit application. If the pool comes with a new house, the rest of that project’s requirements are on new home Title 24 report.
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
Not necessarily. A gas heater can be the supplementary heater behind a heat pump pool heater, or the backup to solar collectors covering at least 60 per cent of the pool surface. Replacing a heater on an existing heated pool is exempt from the sizing rule.
Under §110.4(b)3, an outdoor pool or spa with gas or electric heating equipment must be installed with a cover. An unheated pool is not caught by that rule.
They are exempt from the heating sizing rule in §110.4(c). The compliance manual notes they must still meet the Title 20 efficiency and cover requirements for portable electric spas.
Filtration flow may not exceed the rate needed to turn the pool over in 6 hours, or 36 gpm if that is greater. The manual notes that lower flow rates and longer filtration times save more energy.