DriSteem Vaporstream Specifikace stáhnout pdf (Strana 14)

P a g e 1 0 • D R I - S T E E M D e s i g n G u i d e

D R I - S T E E M D e s i g n G u i d e • P a g e 1 1

Sample Problem 4

Determine the maximum humidification load for an economizer

system located in Minneapolis where:

• The desired conditions in the space are 70 °F and 35% RH.

• The mixed air is 55 °F.

• The total air is 12,000 cfm.

Solution to Sample Problem 4 using

the economizer cycle method

1. Find the moisture content of your desired conditions by

referring to Table 6-1 on Page 6. Read across the 70 °F line to the

35% column, and find 2.40 lbs/hr/100 cfm.

2. Determine the moisture to be added at each 10 °F increment by

using:

• Table 11-1 to find entering RH

• Table 6-1 to find moisture content of entering conditions

• Table 9-1 to find the percentage of outside air

Create a new table with your results by using the following

formula (where H = lbs/hr/cfm):

[H (space) – H (outside air)] × % outside air

× [cfm (total air)/100 cfm] = lbs/hr (load)

Table 12-1 shows data created from the above formula for this

sample problem.

3. Find the maximum humidification load from your created table.

The maximum load for this system is 70.68 lbs/hr and occurs

when the outdoor temperature is 40 °F as shown in Table 12-1.

Notes about economizer cycle method

Economizer “free cooling,” provided

by using outside air, is not always cost

effective. The operating cost advantage of

ambient cooling may be lost when certain

operating conditions prevail, such as:

• The indoor relative humidity requirements

are in a fairly high range (40% RH or

greater).

• Electricity is used to heat water into

steam for humidification.

A crossover point occurs where the

economizer cycle’s increased humidification

energy costs (due to increased air volume

requiring humidification) are more than the

savings derived by outside air cooling.

1 2 ... 9 10 11 12 13 14 15 16 17 18 19 ... 83 84

Komentáře k této Příručce

Žádné komentáře

DriSteem Vaporstream Specifikace Strana 14

Komentáře k této Příručce

Související produkty a manuály pro Odvlhčovače DriSteem Vaporstream