Air Handler Unit which heats and/or cools air. The ahu tag is used model air handling equipment designed to heat or cool air. In Project Haystack, packaged rooftop units are considered a special class of AHU. Packaged units use the ahu tag, but should also specify the rooftop tag: AHUs should always be marked as ahu and equip. The following tags are also used: AHUs should define their heating method using one of the following tags: Cooling method should be defined using one of the following tags: An AHU should be tagged as either constantVolume or variableVolume based on its ability to adjust the volume of air flow. Typically this distinction is based on whether the AHU's fan is single speed or a VFD. The following tags define the system used to deliver air to the zones: A Variable Volume Temperature or VVT system is defined as a constant volume AHU with VAV terminal units. This is indicated by the presence of both the constantVolume and vavZone tags.

In multi-duct systems, the AHU discharges into multiple ducts for simultaneous cooling, heating, or neutral air: Most points in an AHU are associated with one of the following sections of the unit: The follow diagram shows the logical flow of air through an AHU: The following lists points commonly used with an AHU:Single-flow air handling unit / horizontal Single-flow air handling unit / horizontal Stand-alone air handling unit for smaller air volumes, housing mad of insulated panels. Available with TexFog humidifierWhat does AHU mean in Architecture? This page is about the meanings of the acronym/abbreviation/shorthand AHU in the Academic & Science field in general and in the Architecture terminology in particular. This term is used in Air Conditioning designing for buildings Academic & Science » Architecture Find a translation for AHU in other languages: Select another language: - Select -简体中文 (Chinese - Simplified)繁體中文 (Chinese - Traditional)Español (Spanish)日本語 (Japanese)Português (Portuguese)Deutsch (German)العربية (Arabic)Français (French)Русский (Russian)한국어 (Korean)עברית (Hebrew)Український (Ukrainian)اردو (Urdu)Magyar (Hungarian)मानक हिन्दी (Hindi)Indonesia (Indonesian)Italiano (Italian)தமிழ் (Tamil)Türkçe (Turkish)ภาษาไทย (Thai)Tiếng Việt (Vietnamese)Čeština (Czech)Polski (Polish)Bahasa Indonesia (Indonesian)Românește (Romanian)Nederlands (Dutch)Ελληνικά (Greek)Latinum (Latin)Svenska (Swedish)Dansk (Danish)Suomi (Finnish)فارسی (Persian)ייִדיש (Yiddish)Norsk (Norwegian)

What does AHU mean? Ahuthe Asiatic gazelle see more » Embed as a link: Discuss this AHU abbreviation with the community: Use the citation below to add this abbreviation to your bibliography: . STANDS4 LLC, 2016. Use of odors as an indicator of drywall associated corrosion is limited.  Odors have not been reported in all homes exhibiting drywall associated corrosion. Occupant reported health symptoms have limited use in identifying homes with drywall associated corrosion.  The symptoms reported by occupants are not unique or consistent across affected homes. Documenting the presence of odors and/or occupant symptoms may be important to public health agencies, but their relationship to the presence or absence of drywall associated corrosion in homes remains unclear. Sentinel Indicators of Drywall Associated Corrosion (Possible Case = all 3) The home was constructed or renovated with new drywall since 2001. Observed corrosion of air conditioner evaporator coil exemplified by black corrosion on copper tubing components. 

The corrosion can result in refrigerant leakage making it impossible to cool the home requiring coil replacement.  Coil failures indicative of this problem typically occur every 6-14 months Observed metal corrosion, indicated by blackening of one or more of the following: copper wires, ground wires, and electrical connectors un-insulated and un-coated copper pipes and fittings10 ton hvac split system silver and copper jewelryhow to remove ac split unit mirror backing in bathroomscentral air conditioning fan problems If you have answered yes to all three of the above indicators, the home meets the criteria for “possible case”. Continue to Criteria 2 or 3 only if home meets the criteria for “possible case”. 

Trained professionals performing home assessments based upon this case definition should use their experience, training, and professional judgment to establish their inspection procedures and sampling strategies. Professional judgment is necessary to determine the number of samples and weight of evidence needed to meet each set of criteria.  A trained professional, not the homeowner, should conduct inspections and testing described in Criteria 2 and 3. Supporting Indicators of Drywall Associated Corrosion (Probable Case = 1 or more) Observed markings on the back of drywall indicating the country of origin is China. Objective analysis of drywall in home finds Strontium levels exceed 2,000 mg/kg (ppm), indicating the gypsum used in the drywall was probably mined in China.  Analytical methods commonly used for this include XRF and ICP. (2, 3, 5, & 7-12) If you have met the criteria for “possible case” and answered yes to at least one of the above indicators in Criteria 2, the home meets the criteria for “probable case”. 

These criteria do not confirm that the drywall causes corrosion. Identifying the origin of the drywall is considered a screening tool for suspect drywall, but confirmation requires analysis described in Criteria 3. Confirmatory Evidence of Drywall Associated Corrosion (Confirmed Case = 1 or more) Elemental sulfur (Orthorhombic sulfur, cyclooctasulfur, S8) content of gypsum core exceeding 10 mg/kg (ppm), indicating the gypsum in drywall samples from the home contains the source material that is believed to contribute to the reduced sulfur gasses emitted from corrosive drywall. Analytical methods commonly used for this include GC/ECD, GC/MS, or HPLC. (1-4, 6, & 8-11) Laboratory analysis of suspect drywall headspace for reduced sulfur gas emissions (H2S, COS, CS2) indicating drywall samples from the home emit reduced sulfur gasses capable of causing copper corrosion. Analytical methods commonly used for this include GC/SCD.6 Results that are indicative of corrosive drywall must be established by each laboratory based upon internal procedures, comparison to control samples, and validated methods.

Qualitative analysis of suspect drywall for its ability to cause corrosion/blackening of copper under controlled conditions, indicating drywall samples from the home emit gasses capable of corroding copper.  Results that are indicative of corrosive drywall must be established by each laboratory based upon internal procedures, comparison to control samples, and validated methods. If you have met the criteria for “possible case”, ruled out other sources of hydrogen sulfide as significant contributors to copper corrosion in the home, and receive positive results on a sufficient number of samples from one or more of the above evaluations in Criteria 3, the home meets the criteria for a “confirmed case”. Some confounding factors that should be excluded as causes of observed corrosion are hydrogen sulfide from well water, sewer gas, or soil gas. Un-insulated copper pipe1 leading to the air handling unit with signs of blackening corrosion. Un-insulated copper pipe2 leading to the air handling unit with signs of blackening corrosion.

Un-insulated copper pipe3 leading to the air handling unit with signs of blackening corrosion. Un-insulated copper pipe4 leading to the air handling unit with signs of blackening corrosion. Un-insulated copper pipe5 leading to the air handling unit with signs of blackening corrosion. Un-insulated copper pipe1 leading to the air handling unit with no signs of blackening corrosion. Un-insulated copper pipe2 leading to the air handling unit with no signs of blackening corrosion. Un-insulated copper pipe3 leading to the air handling unit with no signs of blackening corrosion. Un-insulated copper pipe4 leading to the air handling unit with no signs of blackening corrosion. Evaporator coil1inside the air handler unit showing blackening corrosion of copper. Evaporator coil2 inside the air handler unit showing blackening corrosion of copper. Evaporator coil3 inside the air handler unit showing blackening corrosion of copper. Blackening corrosion on copper tube of the evaporator coil inside the air handling unit.

Some corrosion has been removed showing un-corroded metal. Evaporator coil showing blue/green and dark red patina on copper tubing and dark orange rust on other metals. Evaporator coil elbows showing dark orange rust on other metals blue/green and dark red patina. Evaporator coils showing blue/green and dark red patina on copper tubing and dark orange rust on other metals. Evaporator coils showing dark red patina on copper tubing and small amount of orange rust on steel. Electrical outlet showing blackening corrosion on the ground wire (bare wire on bottom). Blackening corrosion on the exposed copper of wiring on the electrical panel inside an air handling unit. Blackened in-wall speaker wire. Blackening corrosion on bare ground wires Blue/green patina on the ground wire inside air handling unit. Electrical switch panel with the cover removed showing no corrosion on the bare copper ground wire. Mirror1 showing a slight darkening of the edges.

Mirror2 showing significant darkening of the edges. Mirror3 showing significant darkening of the edges. Mirror4 showing significant darkening of the edges. Light fixture above bathroom vanity showing corrosion of chrome plated surface. Door hinge showing corrosion. Coins and an antique piece of metal that homeowners reported as darkening. Metal finishes on furniture that a homeowner reported as darkening. Water heater in garage with no corrosion on copper water lines. Toilet water shut-off valve showing corrosion. Shower fixture showing corrosion of chrome plating. Bath faucet with black corrosion pitting the chrome plating. Fire sprinkler head showing corrosion. Blackening corrosion1 on copper tubes of a refrigerator. Blackening corrosion2 on copper tubes of a refrigerator. Blackening corrosion3 of a copper water tube leading to a refrigerator. Drywall with "CHINA" markings on a piece of drywall Cut from a wall cavity.