Water Circuit Design - LG MULTI V WATER MINI Engineering Manual

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Table Of Contents

Table of Contents

Figure 17: Open-Type and Closed-Type Tower Design Schematic.

Open-Type

Cooling Tower

First Side

Heat Exchanger

Open-Type Cooling Tower + Heat Exchanger

Heat exchanger is installed between the cooling tower and water

source unit system piping, and the temperature difference between

the first and second sides is maintained constantly.

When using an open cooling tower or open geothermal wells, an intermediate heat exchanger is recommended to be installed to protect the water

source unit from contamination.

Expansion Tank

All closed loop systems must have a bladder type expansion tank installed. The expansion tank will protect the equipment from excess pres-

sures due to expansion and contraction of water in the loop as the temperature changes.

Heat Source and Storage Tank

There are several sources for heat that can be used for this system. They include the following:

• Electric boiler

• Gas boiler

• Solar heat with storage tanks

• Ground source heat

• Steam heat from remote central plant

To deal with thermal flux of the system, if floor space is allowed, a heat storage tank can be installed. The heat storage tank can store

surplus heat or store heat at nighttime when electric rates are lower. Closed type storage tanks are recommended to prevent contamination

of the water system.

Geothermal Water Circuit Design

In lieu of a cooling tower / boiler, Multi V Water Mini units may use a geothermal system that is properly sized to match the water cooled unit

capacity. This year round heating and cooling system will utilize a two (2) pipe closed loop water circuit that circulates water continuously,

maintaining water temperatures between 23°F and 113°F for heating, 23°F and 113°F for cooling (Variable water flow control kit [PRVC1]

required for all entering water temperatures; one kit per frame). When the Multi V Water Mini unit is in cooling mode, heat is rejected to the

geothermal system. When the Multi V Water Mini unit is in heating mode, heat is absorbed from the geothermal system.

Multi V Water Mini units have factory-installed stainless steel plate heat exchangers. To protect these heat exchangers, it is recommended to

use closed geothermal water loops. If open geothermal systems be used, an intermediate heat exchanger must be installed to isolate Multi

V Water Mini units from contaminants in the water system. Open geothermal loops may contain minerals, biological contaminants, corrosive

agents, or other substances which can cause scale, fouling or corrosion, that could degrade performance or shorten the life of the heat

exchanger and unit.

If entering water temperature falls below 42°F, glycol must be added to the system. Refer to antifreeze information on page 45 for recom-

mended levels of antifreeze and correction factors.

WATER CIRCUIT INSTALLATION

Second

Side

Due to our policy of continuous product innovation, some specifications may change without notification.

Closed-Type

Cooling Tower

Closed-Type Cooling Tower

Heat-source water of the cooling tower is supplied directly to the

water source unit system.