PB Heat EC Series Chimney / Vent and Draft Control, Installation Survey, Planning the Layout

PREINSTALLATION

C. CHIMNEY / VENT AND DRAFT CONTROL

An oil-fired unit shall be connected CAUTION to a flue having sufficient draft at all

times, to assure safe proper operation of the unit.

1.Draft Requirement – Minimum draft required in the vent system is -.03" to -.05" W.C. depending on boiler model, see Table 7.1 (Section 7). This draft is necessary to provide the necessary draft over fire of -.01" to -.02" W.C. See discussion in paragraph 5 below regarding draft.

2.Use barometric provided to control draft. Follow manufacturer's instructions to locate and adjust the control.

3.Inspect the existing chimney or vent system. Make sure it is in good condition. Inspect chimney liner and repair or replace if necessary.

4.The vent system and installation must be in accordance with the current edition of the American National Standard ANSI/NFPA 211, "Chimneys, Fireplaces, Vents, and Solid Fuel Burning Appliances," or applicable provisions of the local building codes. See Table 7.1 (Section 7) for typical chimney size. If the vent system is not sized properly, the burner may not operate properly. This can cause poor combustion, sooting and odors to occur.

5.Background Information Regarding Draft:

Modern boilers operate with higher efficiencies than older boilers. Smaller flueways, as well as bars, pins and fins are designed into modern boilers to transfer as much heat as possible from the hot gases to the water or steam and prevent heat loss up the chimney. However, these design features result in higher pressure, or draft loss, in the boiler.

This draft loss must be taken into account when installing an oil boiler into a new or old chimney. New chimneys are less likely to have poor draft.

However, they must have sufficient draft to support combustion. A -.06" draft is desirable and preferred. Older chimneys may require a replacement liner to have them perform well enough to support combustion.

For Example:

	Old	New	Comments
	Installation	Installation
			No change, but older
Chimney	-.04"	-.04"	chimneys (especially unlined
Draft			ones) have leaks which
			reduce draft.
Boiler
Design	+.01"	+.04"	Required for mandated
Pressure			efficiency increases.
Drop
			The old installation would
			have had a higher
Draft	-.03"	0.00"	temperature in the chimney
Over Fire			[as high as 800 degrees vs.
			400 degrees F], which would
			increase the draft.

The above readings are "cold" readings (before the boiler and chimney are heated up).

Note also that the higher the firing rate on a unit which has multiple firing rates, the higher the draft required. For example, increasing the firing rate 1/4 gallon may increase the draft loss in a unit by approximately +.01".

D.INSTALLATION SURVEY

For new and existing installations, a Water Installation Survey or a Steam Installation Survey is available from P.B. Heat, LLC. The surveys will provide information on how the boiler works with your specific system and will provide an overview of boiler system operation in general.

You can also use this survey to locate system problems which will have to be corrected. To obtain copies of these Surveys, contact your PB Heat representative or download it from PeerlessBoilers.com.

E.PLANNING THE LAYOUT

Prepare sketches and notes of the layout of the installation. Include boiler location, venting system, existing piping and wiring. Show existing equipment that may interfere with installation of new equipment.

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