Family Vs State  >  HVAC - "The Smoking Gun"
 HVAC*-"The Smoking Gun" also see Smoking Gun Videos (Vapors shown)
All photos below taken Sept 2003

*Heating Ventilating Air Conditioning  - 15 Photos and Descriptions

High Efficiency (H.E.)  Furnace Induction Exhaust / Intake and (Grilled) "Fresh" (gravity) air intake air (including water heater combustion air) all closely clustered (all within 11 inches of each other) on mid surface of East facing (front) wall.
- The east wall which also is facing the prevalent cold night flow / winds, which produces a mushrooming of exhaust plume, and the positive (barometric) pressure against the wall, driving exhaust contaminated air (furnace fumes) via grill (of gravity air inlet) and open (joist space) pathway into the house interior, which, under its consequent normal winter and/or wind generated negative pressures (created by water heater and original furnace chimney's lift,  vacuum of westward flow /wind effect on all other openings -- windows, doors, fireplace chimney lift, construction leaks, and with exterior-to-interior heat differentials) accepts, distributes, blends, and exposes occupants to in-drafted furnace exhaust fumes.

H.E. Furnace Induction Exhaust / Intake / House fresh air intake (square grill)
 -- and (Grill) "Fresh" (gravity) air intake into home's interior (originally intended as combustion air supply for Water heater and original furnace (which was an older, standard vertical "gravity lift" flue exhaust furnace).
House (Front) East Wall with Furnace Exhaust /Intake
 -- and Vent (behind gutter drain pipe) for "fresh" gravity intake air (including water heater combustion air) (via second floor joist space) into interior alcove space for water heater and the original (older, standard) furnace in lower (basement) floor, and into whole house air.
Note proximity of Furnace exhaust outlet to all house openings:
.  Not only (the <11inches) to grill of fresh gravity air intake vent (right of door, behind down spout),
.  but also to the front door (<4ft) and windows (4'4" upper bedroom window and 5'0" lower family room window) on this (prevailing winter wind striking) East (front) face of home.
.  Also note the 'Trapping' of exhaust plume presented by roof overhangs and porch roof
Furnace Exhaust (upper) and combustion air intake (lower) in proximity (less than 11 inches) to "fresh" gravity air vent (via joist space) into water heater / furnace alcove (in east {front} basement {family} room)
- Note: Screens were added (approx. one and one-half years after purchase) onto openings of furnace intake and exhaust tubes by current buyer (because he presumed that insects which were occasionally pestering occupants were entering living space through these tube -- not understanding this combustion system is a "closed circuit" and not open - unless broken or leaking - to house interior).
- Prior to this screen installation the system was vulnerable to insects, bird or vermin entrance which would have presented added challenge (including squirrel cage fan fin loading / blockage) to proper combustion air supply and exhaust induction, and appropriate combustion
Notice the dirty intake screen (indicating draft of high hydrocarbon (soot) contaminated combustion intake air -- exhaust re-burn or "dirty burn"). Also note flakes of combustion chamber deposits (or coatings) caught on inside of exhaust screen (upper tube).
Heat of exhaust "cooks" off exhaust hydrocarbons (soot), hence the cleaner appearance of exhaust screen, but the cooler intake screen retains drafted hydrocarbon contaminant residues.
Side View Furnace Exhaust/Intake & Fresh Gravity Air Vent cluster
Vent: Joist space carries "fresh" gravity air from outside (by H.E. Furnace Exhaust/Intake Pipes) into Water Heater / Furnace Space (Alcove) inside house. A piece of carpet {now rotted and sagging} was  placed behind grill by privious owners -- appearently to reduce/restrict "cold" outside air (or furnace exhaust fumes) from entering.
Water Heater / Furnace Space: Joist space carrying outside air into alcove is directly above water heater. Also note final horizontal exiting of exhaust and intake PVC tubing in adjacent joist space. Water heater also has a 4 to 3 inch reducer on its flue.
Water Heater / Furnace Space (with joist space carrying outside air is directly above water heater) within East basement 'Family' room.
Note direct freedom of air to pass easily though lovered doors of alcove and continue unobstructed through 'family' (& furnace) room doorway (without door) to ascending stairs to rest of home, including bedrooms above.
Furnace: High Efficiency  Payne, Pulse 90, 88,000 BTU, Natural Gas, subsequently installed with PVC (horizontal exited) flue and intake in place of original standard (Lennox) vertical flued furnace. Change out occurred sometime prior to purchase of home by current (adversely effected) family. Tests showed ingnition and flame-out ("dirty" exhaust re-burn) re-ingintion bursts produced exhaust leakage (high CO, etc) from flame observation glass seal (dark round glass in photo center) and from induction fan seals (see second photo below).
Furnace induction combustion exhaust fan:
Note: Repair of fan has been done with a hand cut gasket -- not a manufacture's exact replacement part.  Also silicon caulking has been wiped on metal tee adapter at induction fan joint (upper center, black steel fitting), also at induction fan base and furnace combustion chamber cover panel joint (lower left).
Silicon wiped on joints of exhaust line pipe (left) -- while none on intake line (right) -- indicating someone previously perceived some kind of exhaust leakage in area!

The Fireplace in Living room, when fired, adds appreciably to (chimney lift caused) negative pressure of domicile's living spaces.
- It would be used in times of profound cold (with furnace also running), causing an even higher drafting rate of air through the only one constantly available (domicile's barometric balancing) fresh (gravity) air vent, adjacent to an already maximum demanded burning furnace's exhaust, on the East facing - and prevalent Easterly winter night winds struck wall.
House crawl space under ground floor section of the Living room and Kitchen (with dining and laundry addition) is tightly sealed, and though 'anti-moisture' vented (3) at south, west and west center (under addition) foundation, with grilled and screened openings, it cannot contribute any air to satisfy negative pressures experienced in the interior living spaces of the domicile.
- So only the one "fresh" (gravity) air intake vent on the home's East wall, adjacent (within 10 inches - click to review photos shown above) to the H.E. furnace exhaust, can perpetually provide inflow of air to satisfy the domicile's negative (barometric) pressure demands.
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Family Vs State  >  HVAC - "The Smoking Gun"also see Smoking Gun Videos (Vapors shown)
Created 9/27/03| edited 9/28/03| last edit 10/1/03   since counter reset.