beautypg.com

87%-efficiency boilers – special instructions – Raypak HI DELTA 302B User Manual

Page 40

background image

40

87%-Efficiency Boilers –

Special Instructions

Water Piping

An 87%-efficiency boiler requires a minimum inlet
water temperature of 120ºF (49ºC) to prevent exces-
sive condensation in the combustion chamber. An
87%-efficiency boiler operated with an inlet tempera-
ture of less than 120ºF (49ºC) must have a manual
bypass or an approved low-temperature operation
system to prevent problems with condensation. A man-
ual bypass, shown in Fig. 15, must be piped into the
system at the time of installation. This piping is like a
primary/secondary boiler installation with a bypass in
the secondary boiler piping. Raypak strongly recomm-

NOTE: The constructions of the 84%- (standard)

and 87%-efficiency (optional) boilers are very similar,
and they are installed to the same requirements,
except as noted in this section.

ends that a thermometer be placed into the boiler inlet
piping next to the in/out header to facilitate tempera-
ture adjustment. Inlet water temperatures below 120ºF
(49ºC) can excessively cool the products of combus-
tion, resulting in condensation on the heat exchanger.

Venting

Appliance Categories

See Table T for appliance category requirements for
the 87%-efficiency Hi Delta.

CAUTION: Proper installation of flue venting is criti-

cal for the safe and efficient operation of the boiler.

NOTE: For additional information on appliance

categorization, see appropriate code NFGC (U.S.)
and B149 (Canada), or applicable local building
codes.

10°F T

20°F T

30°F T

Min. Flow

Max Flow

Model

No.

gpm

P (ft) gpm

P (ft) gpm

P (ft) gpm

P (ft)

T gpm

P (ft)

T

302BE

52

3.3

26

<1.0

N/A

N/A

20

<1.0

26

90

9.8

6

402BE

69

5.8

35

1.5

23

<1.0

20

<1.0

35

90

10.0

8

502BE

87

9.1

44

2.5

29

1.1

22

<1.0

40

90

10.4

10

652BE

N/A

N/A

57

4.4

38

2.0

28

1.1

40

90

10.8

13

752BE

N/A

N/A

65

6.1

44

2.8

33

1.6

40

90

11.3

15

902BE

N/A

N/A

78

8.9

52

4.1

39

2.3

40

90

11.7

17

Combustion

Air Supply

Exhaust

Configuration

Heater Venting

Category

Certified

Materials

Combustion Air

Inlet Material

Vertical Natural Draft

Venting

II

Stainless Steel

(Gas Tight)

From Inside Building

(Non-Direct Venting) Horizontal Through-

the-Wall Venting

IV

AL29-4C

Vertical Natural Draft

Venting

II

Stainless Steel

(Gas Tight)

Galvanized Steel

PVC

From Outside Building

(Direct Venting)

Horizontal Through-

the-Wall Venting

IV

AL29-4C

ABS

CPVC

Table S: Heater Rate of Flow and Pressure Drop

Table T: Category Determination for Venting Purpose and Venting Arrangement

Note: Basis for minimum flow is 20 gpm or 40°F ∆T. Basis for maximum flow is 90 gpm.

This manual is related to the following products: