Spirax Sarco - Catalogo Agosto 2017

Steam traps

Manifolds and insulation jackets

5.10.11

ISO 9001

TI-P117-11

ST Issue 3

Cert. No. LRQ 0963008

Payback Calculator

for IJ-MSC04, IJ-MSC08, IJ-MSC12,

IJ-MSC04-H, IJ-MSC08-H and IJ-MSC12-H

This payback calculator provides a method for calculating the payback period based on the energy saving to be made by fitting an insulation

jacket type IJ-MSC and IJ-MSC-H to a manifold type MSC.

The method equates the cost of energy (to be agreed with the end user), the cost of the insulation jacket (which may include the cost of

installation) and the annual heat loss from the manifold (the ambient temperature is to be agreed with the end user).

The annual heat saving is determined from the graph.

Select the ambient temperature value on the x-axis and run a vertical line up to the operating temperature. Then run a horizontal line to the

y-axis where the value of annual heat saving can be read.

For example, at an ambient temperature of 21°C and an operating temperature of 180°C the annual heat saving will be 6 GJ/year.

The payback period can be calculated using the following equations:

for MSC04 P=

Where:- S =

1 SE

Annual heat saving from graph

Cost of insulation jacket

Cost of energy

Payback period

£ / GJ

year

for MSC08 P=

for MSC12 P=

2 SE

3 SE

J =

E =

P =

The equations are valid providing E and S are in the same units of

energy and E and J are in the same units of currency.

Conversion factors

1 GJ = 1000 MJ

1GJ=9.48x10

BTU

Example 1

Consider a MSC08 operating at 9 bar g, 180°C with an ambient

temperature of 21°C.

From the graph below the annual heat saving, S, is 6 GJ/year.

The cost of insulation jacket, J, including installation is assumed to

be £150

Customer informs us that cost of energy, E, is £5/GJ

Hence:- P=

150

2 SE

2 x 6 x 5

= 2.5years

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Note: The table overleaf gives exact values used to plot this graph.

Intermediate temperatures may be obtained by linear interpolation.

��

Ambient temperature °C

Local regulations may restrict the use of this product to below the conditions quoted.

In the interests of development and improvement of the product, we reserve the right to change the specification.