Cold Air Ducts?

[gator67]

Are there cold air ducts for the furnace, i.e. where the inside air is drawn into the furnace and exhausted? There are wooden grills between the sink and the shower, and another one under the drawers in the kitchen. Are these cold air ducts, or just for show? Are there others?

["007"]

More than likely they are your return air ducts.
With your furnace on place a piece of toilet paper and see if it gets sucked into them.
If not than maybe you have some blockage in them that has to be removed.

[Old Scout]

Furnace location varies from model year to year and from one length to another but the two most likely locations are 1--under bathroom sink so cold air is drawn thru the vent between the bath sink cabinet and the shower [just the one opening] or 2--located under the refridg. So cold air is drawn from vents under the refridg [again only one opening]. The vent under the kitchen sink is an access port. In both cases, the furnace is actually located below the sub-floor in the basement--your outside intake/exhausts vents for the combustion pot should indicate location.

[swansnest]

Jerry -

(Are there cold air ducts for the furnace, i.e. where the inside air is drawn into the furnace and exhausted? There are wooden grills between the sink and the shower, and another one under the drawers in the kitchen. Are these cold air ducts),

Between the bathroom sink and shower is the intake. The vent under the shower and under the kitchen drawers and in the commode room are the hot air ducts for heat.

[dgerstel]

Are you sure that you have a furnace, and not Hydro hot heating, there is a big difference.

[swansnest]

Dale, I don't think any of the '05s had Hydrohot!

[Dave Fernandez]

Jerry when you say cold air ducks do you mean return air to the furnace or air intake for the furnace combustion?

The only return air on a gas furnace should be a large grill some where near the location of the furnace. The air intake for the combustion chamber for the furnace in located outside next to the hot exhaust for the furnace. The intake/exhaust grill is a rectangular shaped stainless steel plate located on the side of the Alpine and looks like the one pictured.

[62Morgan]

Jerry, The inside air is circulated through a closed system. No fresh-air intake and nothing is exhausted to the outdoors. You are seeing the returning-air side that returns the coach air for re-heating by the furnace. They are not decorative; but critically-sized for the air distribution flow needed. They are not to be blocked or closed-off in any way [ie, you see no louver operators of any kind for regulating them].

The furnace is a heat "exchanger" in which the air supply is routed into a box adjacent to a "heated chamber". The burner assembly is a closed system as well. By close proximity to each other the heat is picked-up by the coach air movement through the box. A blower fan keeps the air moving & pushes warmed air outward into the coach. The cold air then finds its way back into furnace exchanger via the grilles you see. [ You will find air movement here to less forceful than the outlets due to the forced-out effect of the supply outlets vs the draft return at the grille.] A sheet of paper will adhere to the grille due to the fan's vacuum effect.

The burner's combustion-air side is the two outdoor openings shown above. These provide the air source for the burner only. Fumes and the heat from burning never enter the coach's air stream; they are confined to these two stainless steel ports on the sidewall exterior.

Again, the coach's air is a closed system. Any rise in humidity levels indoors will not be vented to the outdoors; so you have to be aware of showering, cooking, numerous people inside... etc. and the rise in humidity while using the furnace in cold weather.