Lochinvar 402 - 2072 Location, Hydronic systems anti-freeze, Outdoor boiler installation

1 Determine unit location

Anytime the inlet temperature drops below 45°F, the control turns on the pump contact. If the inlet temperature is below 37°F, and the unit is in the ON Mode, the first stage will fire.

Location

Locate indoor boilers and water heaters in a room having a tem- perature safely above freezing [32°F (0°C)].

Installation & Operation Manual

￿CAUTION

A mechanical room operating under a negative draft pressure may experience a down draft in the flue of a boiler when it is not firing. The cold outside air pulled down the flue may freeze a heat exchanger. This condition must be corrected to provide adequate freeze protection.

Figure 1-2_Outside Combustion Air - Single Opening

Two Openings

The combustion air opening must have a minimum free area of one square inch per 4000 Btu/hr input (5.5 cm2 per kW). You

Hydronic systems anti-freeze

Freeze protection for a heating boiler or hot water supply boiler using an indirect coil can be provided by using hydronic system antifreeze. Follow the appliance manufacturers instructions. Do not use undiluted or automotive type antifreeze (see page 47).

Outdoor boiler installation

Adequate hydronic system antifreeze must be used. A snow screen should be installed to prevent snow and ice accumulation around the unit or its venting system.

Combustion and ventilation air

Provisions for combustion and ventilation air must be in accordance with Air for Combustion and Ventilation, of the latest edition of the National Fuel Gas Code, ANSI Z223.1, in Canada, the latest edition of CAN/CGA-B149 Installation Code for Gas Burning Appliances and Equipment, or applicable provisions of the local building codes.

Provide properly-sized openings to the equipment room to assure adequate combustion air and proper ventilation when the unit is installed with conventional venting or sidewall venting.

Combustion air options

must locate this opening within 12" (30 cm) of the bottom of the enclosure (see FIG. 1-3).

The ventilation air opening must have a minimum free area of one square inch per 4000 Btu/hr input (5.5 cm2 per kW). You must locate this opening within 12" (30 cm) of the top of the enclosure.

Figure 1-3_Outside Combustion Air - Two Openings

2. Outside Combustion Air, Using Ducts

You can direct outside combustion air to this unit using two air ducts to deliver the air to the boiler room (see FIG. 1-5).

Each of the two openings must have a minimum free area of one square inch per 2000 Btu input (11cm2 per kW).

3. Combustion Air from Interior Space

￿CAUTION

Under no circumstances should the equipment room ever be under a negative pressure. Particular care should be taken where exhaust fans, attic fans, clothes dryers, compressors, air handling units, etc., may take away air from the unit.

You can direct combustion air to this unit using air from an adjoining interior space. You must provide two openings from the boiler room to the adjoining room (see FIG. 1-4).

Each of the two openings must have a net free area of one square inch per 1000 Btu input (22cm2 per kW), but not less than 100 square inches (645cm2).

This unit has four combustion air options.

1. Outside Combustion Air, No Ducts

You can direct outside combustion air to this unit using either one or two permanent openings (see FIG. 1-2).

One Opening

The opening must have a minimum free area of one square inch per 3000 Btu input (7 cm2 per kW). You must locate this opening within 12" (30 cm) of the top of the enclosure.

10 Figure 1-4_Combustion Air from Interior Space