BENSON VRC-3 100-3, Installation, Service And User Instructions Manual

1704VRC3-AMEN, p 18/35 

Figure

2b

:

Combustion

air

and

flue

pipe

sockets,

Type

C

Table

6

Combustion

air

inlet

&

flue

pipe

requirements

1 

Flue

pipe

outlet

collar

2

Combustion

air

pipe

inlet

collar

3.4

Air

supply

It

is

important

to

ensure

that

there

is

an

adequate

air

supply

at

all

times

for

both

com

‐

bustion

and

heating

requirements.

Modern

constructions

involve

the

greater

use

of

insulation,

improved

vapor

barriers,

and

weather

proofing.

This

practice

means

that

buildings

are

sealed

much

tighter

than

in

the

past.

The

combustion

air

supply

for

a

power

vented

gas

fired

air

heater

(Type

B

installation)

can

be

affected

by

lack

of

air

supply.

Natural

infiltration

may

not

be

adequate.

Use

of

extract

fans

aggravates

this

situation.

It

is

important

to

ensure

that

there

is

an

adequate

air

supply

at

all

times.

Reliance

on

doors

and

windows

is

not

allowed.

Always

ensure

that

an

adequate

inlet

for

fresh

air

for

combustion

is

provided

sized

to

suit

the

total

installation

of

any

combustion

apparatus.

Fit

an

access

guard

to

the

combustion

air

inlet

on

the

back

of

the

heater

and

take

appropriate

action

to

ensure

that

it

remains

unblocked.

See

figure

2c.

WARNING:

This

model

air

heater

is

installed

as

a

type

B

application

and

is

designed

to

take

air

for

combustion

from

the

space

in

which

it

is

installed.

Do

not

restrict

the

combustion

air

intake.

Figure

2c

Combustion

air

and

flue

pipe

sockets,

Type

B

1

2

1 

Flue pipe outlet collar  

2 

combustion air inlet opening 

3.5

Air

distribution

Follow

recommended

practice

for

building

air

distribution.

The

following

notes

are

of

particular

importance:

"Where

free

blowing

air

heaters

are

installed

it

must

be

taken

into

account

that

heated

air

is

buoyant

when

it

leaves

the

appliance,

therefore,

air

patterns

within

the

space

being

heated

will

modify

the

air

throw

pattern

achieved.

In

building

having

low

heat

loss

where

single

heaters

are

required

to

cover

a

large

floor

area

and

in

buildings

with

high

ceiling

heights,

air

re

‐

circulation

fans

may

be

fitted

to

ensure

even

heat

distribution

and

minimize

stratification.

Care

should

be

taken

to

avoid

impeding

air

flow

with

storage

racking,

partitions,

etc."

3.6

Electrical

supply

Wiring

external

to

the

air

heater

must

be

carried

out

in

accordance

with

the

rules

in

force

and

by

appropriately

qualified

persons.

A

constant

230

Volt

50

Hertz

single

phase

fused

electricity

supply

with

neutral

link

is

required.

All

heaters

and

controls

must

be

earthed.

A

lockable

isolator

with

contact

separation

of

at

least

3.0

mm

on

all

poles

should

be

installed

adjacent

to

the

appliance

and

within

reach

of

any

person

working

on

the

heater.

1

2

VRC-3

Flue pipe

Inlet pipe

Flue pipe

Inlet pipe

Flue pipe

Inlet pipe

Flue pipe

Inlet pipe

1,5

Heater socket
& pipe dia

mm

Max. straight
length

m

9

9

Concentric vertical vent or wall terminal : Mugro/Burfix dia 130
Concentric horizontal vent or roof terminal : Mugro/Burfix dia 130

Equivalent length
of 45° elbow

Equivalent length
of 90° elbow

m

m

1,5

0,75

0,75

20 & 30

other sizes

100

100

130

130