Roof drying processes and associated systems. A representative process includes drawing moisture-laden air from within the internal structure of a roof via a vacuum blower, a extraction insert and an extraction manifold, and removing moisture from the moisture-laden air via a dehumidifier. The dry air can be directed back into the roof through an injection insert and an injection manifold.

A structure comprises at least one outer wall having an internal wall section and an outer wall section with an air flow passage therebetween. A circulation system circulates air through the flow passage to inhibit moisture accumulation and mold growth. A sensing system determines the presence of moisture in the flow passage and generates a signal in response thereto. A controller receives the signal from the sensing system and controls the circulation system to maintain a predetermined temperature and relative humidity in the flow passage.

In an embodiment of the invention, a dripless air conditioning (A/C) vent includes a vent diffuser in communication with an A/C vent. The vent diffuser includes a pair of end cap components fabricated from poly-vinyl chloride (PVC) and a pair of side channel rails also fabricated from PVC and arranged oppositely to one another, each side channel rail secured at each distal end to a corresponding one of the end cap components. The vent diffuser further includes at least one inside channel rail also fabricated from PVC and secured at each distal end to a corresponding one of the end cap components at a position intermediate to where each side channel rail is secured and a middle cap arranged perpendicularly to each of the channel rails and secured to a common bottom face of each of the channel rails.

A method of providing cooled air to electronic equipment includes capturing heated air from a volume containing electronic equipment, cooling the heated air by more than fifteen degrees Celsius in an air-to-water heat exchanger, and supplying cooling water to the air-to-water heat exchanger at a temperature above a dew point temperature of the heated air.

An outdoor unit for an air-conditioning apparatus is configured to suppress damage on hairpin portions at an end portion of an outdoor heat exchanger due to freezing. The outdoor unit includes: an air passage defined inside a casing; an outdoor heat exchanger, which is installed in the air passage, and includes a plurality of heat exchange portions; an outdoor unit fan configured to introduce air into the outdoor heat exchanger; and an air passage blocking object installed in the air passage, and configured to block air flow. The outdoor heat exchanger includes: a heat transfer tube configured to allow refrigerant to pass therein; and a fin connected to the heat transfer tube. The heat transfer tube includes a hairpin portion, which is bent and folded back and to which no fin is connected. The air passage blocking object is configured to cover the hairpin portion.

A total heat exchange device includes: a fan for the exhaust air path which directs air from an indoor exhaust port to an outdoor discharge port through an exhaust air path; another fan for intake air path which directs air from an outdoor suction port to an indoor intake port through an intake air path; and a heat exchange element for exchanging heat between air passing through the exhaust air path and air passing through the intake air path. Also included is a temperature detector for detecting an outdoor temperature and a controller configured to perform a heat exchange mode in which heat is exchanged between air passing through the exhaust air path and air passing through the intake air path or a defrosting mode in which frost on the heat exchange element is thawed, in accordance with the outdoor temperature detected by the temperature detector.

A heat exchanger of the present disclosure is operated in a cooling operation mode in which a region to be heat-exchanged is cooled by the heat exchanger or in a drying operation mode in which the heat exchanger is supplied with wind from a blowing fan, and comprises: a refrigerant pipe which forms a flow path of a refrigerant; a cooling fin which is coupled to the refrigerant pipe; and a hydrophilic coating with which the surface of at least one of the refrigerant pipe and the cooling fin is coated, wherein the hydrophilic coating contains: a first type transition metal oxide which becomes acidic by reacting with water formed on the refrigerant pipe or the cooling fin, so as to have antimicrobial activity when the heat exchanger is operated in the cooling operation mode; and a second type transition metal oxide or a post transition metal oxide which has antimicrobial activity when the heat exchanger is operated in the drying operation mode.

A steam dispersion apparatus includes a steam chamber communicating in an open-loop arrangement with a first steam source for supplying steam to the steam chamber. The steam chamber includes a steam dispersion location at which steam exits therefrom at generally atmospheric pressure. A heat exchanger communicates in a closed-loop arrangement with a second steam source for supplying steam to the heat exchanger at a pressure generally higher than atmospheric pressure. The heat exchanger is located at a location that is not directly exposed to the air to be humidified, the heat exchanger being in fluid communication with the steam chamber so as to contact condensate from the steam chamber. The heat exchanger converts condensate formed by the steam chamber back to steam when the condensate contacts the heat exchanger.

Control systems are provided that provide thermodynamically decoupled control of temperature and relative humidity and/or reduce or prevent frost formation or remove previously-formed frost. The control systems herein may be included as a component of a heating, ventilation, air conditioning, and refrigeration system that includes a heat exchanger.

A stepped damper for a vertical column of an HVAC air handling unit is disclosed. The stepped damper includes a series of offset pivoting blades which, when closed, form a continuous slope running to a drain. In this way, the pivoting blades, when closed, form a ramp that functions to direct any fluid, condensation, or moisture down the ramp and toward the drain located at a low point along the stepped damper. The stepped damper of the present invention is adapted for positioning within a vertical column of an HVAC air handling unit, for example, a vertical air intake column, such that the stepped damper sits adjacent the top of the vertical column for preventing undesired objects from entering the vertical column. The present stepped damper is particularly adapted for preventing any fluid, condensation, or moisture from flowing down and into the vertical column.