line s

thermostats are

essentially temperature actuated switches

3 different types of residential switches

line voltage, low voltage, electronic

line voltage thermostats

act as an on/off switch to conduct full power to the heater

low-voltage thermostats

are primarily for high amperage electric heating systems. they operate on 24v power source supplied by a transformer, the light construction of these thermostats allow them to be highly responsive and provide more accurate control

electronic thermostats

are extra low voltage and use semiconductor components for both temperature sensing and control circuit switching

room thermostats should be mounted approximately

1.5m above floor

baseboard heaters watts per foot

250w/ft

baseboard advantages

long life, low maintenance, clean, efficient, environmentally friendly

baseboard disadvantages

heat movement mostly up, need multiple thermostats for entire house

electric heaters commonly use resistance wires such as

nichrome

you install baseboard heaters at

floor level, preferably under windows or other areas at high heat loss

unit heaters

are small and compact, yet have high heating capacity

unit heaters contain

a heating element, a blower fan, and usually comes with louvres and diffusers to direct the airflow/ a fan switch is often provided to allow for air circulation in warm weather without operating the heater elements

the unit heater can be installed at

the ceiling or wall, or recessed into a wall

electric furnaces

an electric furnace is compose of a blower heater combination(furnace), which forces hot air through ductwork via floor registers

the electric furnace contains

several resistance heating elements, a circulating fan, and an air filter. the unit also houses the contactors (relays) blower controls, and a high temperature safety cutout

electric furnaces heating elements are normally switched

in increments of 5 kw or less to reduce line drops that can result in the flickering of lights when large loads are switched

gas-fired forced-air furnaces

they operate on the same principle as electric furnaces. a blower is used to force heated air through ductwork via floor registers

furnaces are usually located in

the basement or crawl space of a house

furnaces operate on the principle of which

a fan draws return air from the living/dining room area, passes it through the heat exchanger, then blows the warm air to the rooms

supply registers for for furnaces are located

they are generally located around the perimeter of the room, preferably in front of areas of high heat loss

furnace ventilation

because the combustion gases and smoke cannot be vented into the house, a heat exchanger is required to keep the products of combustion separated from the circulated air. the circulated air passes over the heat exchanger piping, picking up the heat

gas fired furnaces operate in operation, the biggest difference is

how the main burners are ignited, direct spark ignition (dsi) , electrically heated hot surface ingniter similar to diesel engine glow plug, while others use continuously burning pilot light

the room thermostat controls the gas valve or blower motor

the gas valve

the purpose of a anticipator in a room thermostat for a furnace is

to prevent overshoot

a thermocouple