HVAC_Heating_Cooling Flashcards
(16 cards)
Why are hydronic systems generally not used for cooling?
They don’t radiate coolness well and cause condensation issues.
What is a ‘cool beam’ system in HVAC?
It uses cold water pipes in ceiling trays to cool warm air rising from occupants, which then falls back cooled.
How do cool beams avoid radiant cooling problems?
They use convection by cooling warm air, not the body directly.
Why is dehumidification necessary in cool beam systems?
To prevent excessive condensation buildup that could drip onto occupants.
What is one major advantage of steam heating systems?
They require no pumps or fans; steam moves naturally through the system.
Why does steam create suction in the system?
As steam condenses back into water, it decreases in volume, pulling more steam through.
What is a key requirement for condensate return lines in steam systems?
They must flow downhill to avoid ponding and pipe damage.
Where are steam systems still commonly used?
Large campuses or multi-building complexes where centralized heating is efficient.
What does a baseboard radiator below a window help prevent?
Condensation on glass and radiant heat loss from occupants to the cold window.
How does a baseboard radiator help with air circulation?
It creates a convective current that warms the cold air near the floor.
Why is electric heating efficient at point-of-use?
Almost all input electricity converts directly to heat.
Why is electric heating generally considered inefficient overall?
Electricity generation is often inefficient and polluting.
In what situations is electric heating ideal?
Remote locations, infrequent use, or where electricity is cheap (e.g., near hydroelectric dams).
What is a common use of electric radiant floor heating?
Supplemental warmth in tiled bathrooms or kitchens.
Why isn’t electric radiant floor heating good as a primary heat source?
Small wires can fail over time and are difficult to repair when embedded in floors.
How is electric heat used to melt snow?
Electric lines embedded in sidewalks activate only during select conditions to melt snow/ice.
