HYDRONICS CHAPTER 8

In Northern climates, low-temperature limit switches are installed that force dampers to close and activate the heating system to ____% when the outdoor low-temperature limit is reached

100%

Average flow through a coil should not exceed?

8 FPS

Air handling units

A basic hydronic air handling unit (AHU) consists of an air filter, one or more cooling and or heating coils and a fan. other items such as dampers and humidifiers may be included. As opposed to the individual room type units discussed earlier, air handling units are classified as central station units and are intended to be used with a substantial amount of ductwork to supply a number of rooms or areas with conditioned air.

Of the types of chilled beams ____ systems are similar to convection systems and have ventilation air delivered through ductwork by a central air-handling system

Active

How does copper tube aluminum fin baseboard compare to cast iron baseboard?

BTU output the same however aluminum fin copper tube baseboard can be installed much quicker.

The ____ in a cabinet heater adds energy to the air so that directional louvers can be used on the top or front of the heater to distribute the air more efficiently in a building space.

Blower

A ____ convection unit is a convection terminal unit that creates convective currents by mechanically moving air pst a terminal unit element.

Cabinet

Types of radiant cooling terminal units.

Chilled beams and radiant cooling ceiling panels

Four advantages of baseboard radiator units are that they are large, they operate cleanly, they interfere only minimally with furniture placement, and the distribute the heat near the floor. (T/F)

FALSE (Baseboard radiators are small not large in comparison to other types of heating units)

Efficiency units include a desiccant wheel to dehumidify air and an energy recovery wheel to separately control the humidity and temperature of conditioned air (T/F)

FALSE (Environmental units)

In most cases, the inlet to a heating coil is on the top of the coil, and the outlet is on the bottom (T/F)

FALSE (Inlet is typically on the bottom and outlet is on the top)

The most recognizable type of radiator is the standing radiator that has a section of horizontal tubes that are connected with headers at each end (T/F)

FALSE (Vertical)

Cast-iron baseboards and baseboards with finned type copper tube or steel pipe heating elements can be mixed on the same circuit, since the cast-iron type usually holds the same amount of water as the finned copper type. (T/F)

FALSE (cast iron baseboard holds much more water than finned copper tube)

All air-handling systems use some form of humidity control to add moisture to building air during the winter heating periods (T/F)

FALSE (common but not a given)

A ____ is intended to supply air only to the room where it is located

Fan coil unit

Fewer paths in a coil means?

Fewer paths in a coil the higher the velocity of the HTF and the higher the rate of heat transfer and coil capacity however the pressure drop of the HTF will also be higher.

There are ____ types of hydronic heating forced-air convection units

Four (cabinet unit heaters, kicks pace convection heaters, unit heaters, and unit ventilators)

Cast Iron Radiators

Has sections of vertical tubes that are connected with headers at each end. direct type of heat transfer also creates natural convection currents. no longer made

As chilled water temperature increase, less moisture condenses out of the air, and the RH

Increases

Baseboard Radiator

Kind you have in home installed along outside walls under windows also called fin tube. (Bending of fins restricts heat transfer important to keep protected)

In most cases, a cooling system will reduce the humidity levels in a space by removing the ____ heat of the moisture in the air

Latent

Radiant panel baseboard

New style. two tubes of copper, PEX, or copper line aluminum attached to the back of panel. snaps into brackets on wall very low profile 1/2"

Panel Radiator

Radiator designed to function more efficiently at lower HTF temperatures than a traditional radiator. Usually individual not an integral part of a building and are used for spot heating. (ALSO CAN BE ART)

Types of radiant heating terminal units

Radiators and radiant panels

A (n) ____ of conditioned spaces below 30% tends tor educe moisture levels in occupants, which can result in respiratory infections, dry skin, and general discomfort.

Relative humidity

Chilled beam Passive

Similar to radiant systems. heat flows from surfaces up towards chilled beam as long as there are warmer temperatures within that space. Heat is absorbed by the chilled HTF and returned as warmer HTF to the chiller

____ systems are used on driveways, walkways, parking areas, stairways, ramps, loading docks, and other outside surfaces.

Snow melt

A radiant ceiling panel grid can be embedded into a new ceiling, or preformed panels can be mounted to the surface of a ceiling (T/F)

TRUE

Although not technically a cabinet unit heater, a kickspace heater is ideal for use in kitchen, bathroom or other are where there is not enough wall space for a baseboard radiator or convection unit (T/F)

TRUE

Currently, the copper tube with aluminum fin type baseboard radiator is commonly used. (T/F)

TRUE

The taller the cabinet heater, the higher the heat output. (T/F)

TRUE

There are two types of convection units, natural convection units, which depend upon natural gravity to circulate the air, and forced convection units, which utilize fans or blowers to move air across the unit's element (T/F)

TRUE

A (n) ____ is a hydronic system component that transfers heat between the heat transfer fluid (HTF) flowing through it and the air in building spaces

Terminal Unit

There are ____ types of terminal units commonly used in hydronic heating systems.

Two (Radiant heating units and convection units)

A ____ heater is a self-contained, forced-air convection heater that is not connected to ductwork and contains a fan, an HTF coil, and controls in one cabinet.

Unit

Where dissimilar metals are present any of the following can be used except

a

Difference between baseboard convection unit and baseboard radiator.

almost identical. tube size may be smaller in baseboard convection unit due to the greater heat output of the unit.

Cabinet unit heater

forced air convection heater that has a blower or fan. difference to cabinet convection units is that the blower or fan moves the air and a filter cleans the air. Used where a large quantity of heat from a single unit is required.

Fan coil units

hydronic terminal unit that uses a fan to blow room air over a coil through which heated or chilled HTF is circulated. exists in ductwork does not bring in outside air.

kickspace convection heaters

multipurpose hydronic forced air convection heater consisting of an HTF coil, a fan, and an enclosure and is small enough to fit in the kickspace under a set of cabinets or vanities.

cabinet convection unit

natural convection terminal unit enclosed in a cabinet. grill in bottom and top for cool and warm air respectively. available in freestanding, semi-recessed, wall-hung, and full recessed.

Chilled beam Active

similar to convection systems ventilation air delivered through ductwork. Cool air is forced out the ductwork after it flows over the chilled beam. warm air then flows up to the beam to be cooled and re circulated.

Unit ventilators

similar to unit heaters however bring in outside air.

Radiat panels

system that heats a space by increasing temperature of one of its interior surfaces. releases 55%-70% of its heat to a room by radiation and the rest by convection.

Cleanable tub coils

two types one type includes a removable cover at each end and one with removable plug. cleanable tub coils are desirable in situations where tubes may become clogged or fouled form a considerable mineral content

Baseboard convection Unit

used finned tube enclosed in a low cabinet installed along a baseboard. type of natural convection unit