CHAPTER 8Mechanical Systems and Insulation

This is a cable located outside a house

It provides electricity service through underground or overhead wires from the road to the structure

It typically provides 240 Volts electricity from the street supply◦ The size of the entrance cable controls the

amount of electricity that is available

Electrical Service Entrance Cable

Electric service size describes the number of amps that are provided to any structure through a primary wire service

Once the power enters a structure, it travels to a main disconnect with 2 circuit breakers or fuses ◦ One fuse is for the negative black wire while the other is

for the positive red wire◦ Fuses are rated according to the amperage that the wire

can carry safely (e.g. 60 amps / 100 amps etc.)

Service size is determined by the thickness of the cables

Electric Service Size

Distribution panels are electrical panels that are located between service entrance wires and power distribution in any structure

It acts as an interface and is connected by service wires to the main disconnect

Types of distribution panels:1. Knob and tube (old system, prone to fire, results in high

insurance premiums)2. Circuit breakers (new industry standard, safer and cheaper

to insure)

Some properties in downtown Toronto still have knob and tube distribution panels

Distribution Panel

What type of electricity distribution is more expensive to insure and most prone to fire?◦ Knob and tube

What is the name of the distribution panel type that replaced knob and tube?◦ Circuit breakers

RECAP

An electricity main disconnect switch provides people with the option to shut-off-all power in a structure◦ It is the main power switch for a structure

Switch handles are typically located outside the structure while breakers or main fuses are located inside the main structure

Hydro authorities frequently seal covers onto the main disconnect so that only they are able to access it

Electricity Main Disconnect

A grounded outlet is the third ground wire◦ It does not conduct electricity◦ It grounds excess electricity◦ It acts as a safety measure

Grounding is a process by which electricity is diverted to the ground

Positive wire = red/white, negative wire = red, ground wire = copper/green

Grounded Outlets

What color is the ground wire?◦ The grounded outlet wire is green

What is the function of the grounded outlet?◦ It grounds excess electricity or bypasses

electricity to the ground

RECAP

Heating systems are used to keep structures warm

There are several types of systems:1. Steam2. Warm air3. Radiant4. Electrical5. Hot water

Heating Systems

Furnaces are central heating systems that generate heat in one location and distribute it to different parts of the structure◦ Distribution normally happens through sheet

metal ducts

All furnaces except electric furnaces have:1. Heat Exchanger2. Burner3. Blower

Furnaces

Electric furnaces have heating elements/coils

Convection is the movement caused by hot and cold ◦ Cooler gasses are more dense and they sink because of

gravity◦ Hotter gases are less dense and rise because of gravity ◦ This movement results in the transfer of heat

Convectional refers to heat generated by coils or burning gas◦ It is distributed through structures by a fan

Furnaces

Types of furnaces1. Electrical furnace

Does not rely on actual combustion, which means it does not have a chimney, burner or heat exchanger

Instead, it has heating elements Blower forces air across heating element to warm air,

and the air is circulated in the home through ducts2. Gas furnace

Four types1. Convectional2. Mid-efficiency3. High-efficiency4. High-efficiency pulse

Furnaces

3. Gravity Furnace/Octopus Furnace Function the same way as a convectional furnace but

do not have a fan to blow air through the ducts It uses convection (gravity) to circulate hot air It has 8 pipes going to 8 different rooms which is why it

is called Octopus Furnace Pipes carry hot air, which rises as cool air sinks to the

ground Cool air returns to furnace through an inlet These furnaces are obsolete because of their high level

of inefficiency4. Oil Furnace

Similar to gas furnace Oil must be stored on site to operate it

Furnaces

What is the main difference between a conventional furnace and a gravity furnace?◦ A gravity furnace does not have a fan

Which furnace type has a radiator?◦ Convectional furnace

What kind of furnace is a gas furnace?◦ Convectional

What is an octopus furnace?◦ A convectional and gravity furnace

RECAP

A boiler is a heating system that generates heat in one location and distributes it through pipes to other locations in a structure◦ They are made up of open and closed systems

Hot water systems do not boil water but heat it to a maximum of 160 degrees Fahrenheit

Boilers have two primary components:1. Heat exchanger which contains natural gas or oil on

one side and the water that will be heated on the other

2. Boiler

Boiler

Types of boiler systems1. Closed-boiler system

Does not have overflow expansion pipe or tank It is industry standard these days Has circulating pump that forces water throughout

home pipe system

2. Open-boiler system Has overflow expansion pipe or tank Old system that has been discontinued It requires expansion tank which is typically placed

above the highest radiator in a structure This tank allows for expansion when the water is heated It does not require a pump since it makes use of gravity

Boiler

HVAC = “heating, ventilation and air conditioning” ◦ It is a heating/cooling system used in commercial

buildings typically mounted above ceilings ◦ It ensures even distribution of fresh air, heating and

cooling throughout a structure

HVAC has the following components:1. Air handler = series of fans that moves air2. Ductwork = ducts transport air through structure3. Condensing unit = compresses the Freon gas that

is used to cool air; is placed outside the structure4. Roof Top HVAC = mounted on roof of structure

HVAC

Chimneys are vertical structures that contain a single or multiple flues that help discharge smoke/gases from a furnace or fire

Chimneys are no longer required and are often removed till they are below roof-level during re-roofing◦ This means you don’t have to worry about

maintaining them◦ It also reduces risk of water leakage from chimney

flashing (see flashing)

Chimney

A flue is a distinct and separate channel that allows for smoke in the chimney

A cap is a structure above the chimney that prevents water from entering it

Chimney Flue and Cap

Classes of drainage systems1. Class 1 – no tank

Waterless toilets with pit; found on construction sites2. Class 2 – no tank

Can only be used for non-human waste, called grey-water system

3. Class 3 – no tank Uses cesspool, similar to class 2 but used for human

waste4. Class 4 – has a tank

Private drainage system that is common in rural areas, called leeching bed system

5. Class 5 – has a tank Holding tank, not private drainage system Emptied by collection company

Drainage Systems

Class 4 and 5 are used in rural and recreational areas

Class 4 system includes:1. Septic tank – which has bacteria that

eats/decomposes waste2. Leeching bed – filter with holes surrounded by

filter materials such as sand

Drainage Systems

Types of leeching beds1. Conventional Leeching Bed

Most common Installed where land well-drained and bed can work

using stone-filled trenches dug below ground level Water is allowed to leech back into ground water,

filtering through various layers of ground 2. Raised

Second most common Used where landscape doesn’t allow for self-filtration Filtering materials are brought onsite and a raised

bed is made for stone-filled trenches

Drainage Systems

3. Filter Used only when space is limited The entire bed is excavated and filled with special

filtering sand that allow for closer pipes within the bed

Class 5 Holding Tank◦ It is the porta-potty system where tank

periodically emptied by waste removal services

Drainage Systems

Class 4 septic tank system is a private drainage system

Class 4 septic tank system consists of an absorption bed or leeching bed

Class 4 septic tank is a treatment tank

RECAP

R-2000 is an energy efficiency program pertaining to the construction of new homes

It sets performance standards that are more stringent than those stated in Building Codes

It is the most energy efficient construction designation and includes all things energy efficient, such as solar panel roofs and CSA standard windows

R-2000