Corpus sync: neutrality remakes, note hygiene, datasheet relocation, transformer-split cross-refs
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title: Terminal Heating Units
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−## Capacity ratings shall be submitted at the scheduled entering and leaving water temperatures, not at a generic catalog condition, so that the reviewer can confirm the unit performs at the actual system supply temperature. {note}
+## Capacity ratings shall be submitted at the scheduled entering and leaving water temperatures, not at a generic catalog condition, so that the reviewer can confirm the unit performs at the actual system supply temperature.
## Closeout Submittals {toc}
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## Hydronic and steam unit heaters shall be listed to UL 1995 or an equivalent NRTL standard for heating equipment.
−## The manufacturer shall have produced terminal heating units of the specified type for not less than five years. {note}
+## The manufacturer shall have produced terminal heating units of the specified type for not less than five years.
## A listing label demonstrates that the unit's electrical construction, element guarding, and over-temperature protection were evaluated by an independent laboratory; an unlisted electric heater is not acceptable for a code-compliant installation. {note}
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## Units in car washes, natatoriums, food-service areas, chemical or pharmaceutical spaces, or coastal locations shall be provided with stainless steel or epoxy-coated enclosures and coil protection.
−## A standard baked-enamel steel cabinet corrodes within a season in a wash-down or chlorinated environment; the corrosion-resistant enclosure and coil coating must be specified explicitly because it is not the catalog default. {note}
+## A standard baked-enamel steel cabinet corrodes within a season in a wash-down or chlorinated environment; the corrosion-resistant enclosure and coil coating must be specified explicitly because it is not the catalog default.
## Cabinet units in occupied spaces shall be provided with a baked-enamel or powder-coat finish in the color selected from the manufacturer's standard range. [[drawing: architectural finish schedule]]
−## Architectural enclosures shall align with adjacent wall finishes and reveals where the unit is exposed in a finished space. {note}
+## Architectural enclosures shall align with adjacent wall finishes and reveals where the unit is exposed in a finished space.
# Electrical {toc}
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−## A voltage mismatch — an electric heater ordered for 240 V on a 277 V lighting panel, or the reverse — is among the most common field problems on this equipment and produces a non-functional unit and a change order; the voltage must be coordinated with the serving panel before ordering. {note}
+## A voltage mismatch — an electric heater ordered for 240 V on a 277 V lighting panel, or the reverse — is among the most common field problems on this equipment and produces a non-functional unit and a change order; the voltage must be coordinated with the serving panel before ordering.
## Branch-circuit conductors, overcurrent protection, and disconnecting means shall be sized and provided in accordance with NFPA 70 Articles 424 and 210 for the unit's minimum circuit ampacity.
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## A fan that runs while the control valve is closed blows unheated air into the space, which feels like a draft and wastes fan energy; the end-switch interlock prevents cold-blow by holding the fan off until the valve opens. {note}
−## Modulating units served by a variable-speed plant shall be provided with a 0-10 V modulating valve actuator compatible with the BAS, as coordinated with [[sync/hvac-variable-frequency-drives]] where applicable. {note}
+## Modulating units served by a variable-speed plant shall be provided with a 0-10 V modulating valve actuator compatible with the BAS, as coordinated with [[sync/hvac-variable-frequency-drives]] where applicable.
# Freeze Protection {toc}
−## Any hydronic or steam unit serving a vestibule, entry, loading dock, or other space exposed to freezing air shall be provided with a freeze-protection strategy; omitting it is a leading cause of coil failure. {note}
+## Any hydronic or steam unit serving a vestibule, entry, loading dock, or other space exposed to freezing air shall be provided with a freeze-protection strategy; omitting it is a leading cause of coil failure.
## The Contractor shall provide the freeze-protection method indicated for each unit exposed to freezing conditions.
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−## Specifying a vestibule or loading dock unit with no aquastat, no heat trace, and no continuous-flow provision leaves the coil to freeze the first time the entry door is propped open in cold weather; the freeze-protection method must be an explicit part of the specification, not an afterthought. {note}
+## Specifying a vestibule or loading dock unit with no aquastat, no heat trace, and no continuous-flow provision leaves the coil to freeze the first time the entry door is propped open in cold weather; the freeze-protection method must be an explicit part of the specification, not an afterthought.
## Where glycol is used for freeze protection, the solution concentration shall be selected for the design low temperature and the coil capacity shall be re-rated for the glycol solution's reduced heat-transfer performance.
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## Suspended and wall-mounted units shall be installed with the clearances required for filter, motor, and trap access, coordinated with the reflected ceiling plan and adjacent construction. [[drawing: reflected ceiling plan]]
−## Cabinet units installed too close to a wall or recessed into a tight pocket cannot be serviced; the access clearances must be coordinated with the architecture before rough-in, because a unit that cannot be opened cannot have its filter or motor changed. {note}
+## Cabinet units installed too close to a wall or recessed into a tight pocket cannot be serviced; the access clearances must be coordinated with the architecture before rough-in, because a unit that cannot be opened cannot have its filter or motor changed.
## Ceiling-suspended propeller and blower units shall be supported and braced against seismic loads in accordance with ASCE 7 for the project's seismic design category.
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## Hydronic and steam connections shall be made with unions or flanges at the unit so the unit can be isolated and removed without cutting piping.
−## Each hydronic unit shall be provided with a means of isolation, balancing, and air venting at the coil so the coil can be served and balanced independently. {note}
+## Each hydronic unit shall be provided with a means of isolation, balancing, and air venting at the coil so the coil can be served and balanced independently.
## Filters in cabinet and force-flow units shall be installed accessible for replacement from the front or bottom of the unit without dismantling the enclosure.
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## Startup shall confirm correct fan rotation, valve and damper operation, thermostat or BAS response, and freeze-protection cutout operation where provided.
−## The freeze-protection aquastat or low-limit shall be tested by simulating a low coil temperature and confirming the fan de-energizes. {note}
+## The freeze-protection aquastat or low-limit shall be tested by simulating a low coil temperature and confirming the fan de-energizes.
## Electric units shall be tested to confirm the element thermal cutout de-energizes the element on simulated over-temperature.
−## Test results shall be recorded and submitted in the field quality-control report. {note}
+## Test results shall be recorded and submitted in the field quality-control report.
# Delivery, Storage, and Handling {toc}
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−## Replacement filters shall match the size and rating recorded in the closeout filter schedule so the owner can reorder without re-measuring. {note}
+## Replacement filters shall match the size and rating recorded in the closeout filter schedule so the owner can reorder without re-measuring.