greetings,
i inspected a house yesterday (c.1890 bungalow) and the cold air return was about 8 inches away from the furnace. old small, unfinished, cellar basement. the duct extended to about 5 inches to the floor. hot water tank was about 12-15 feet away. i didnt see anyplace upstairs where air could also be drawing from. ive seen a few lately.
im telling my clients and noting that maintenance may be required to maintain safe operation around other fuel burning appliances. i dont want to give the impression that these issues must be addressed ASAP, but we cant really expect sellers to modify these old systems. this obviously doesnt fly in modern building, but what are you all recommending on these 50 year old installations?
i usualy state the fact first. weather or it functions properly, then inform them about it antiquety, modern advantages and so on. maybe even sight a few example in a “small talk” situation, and let them decide from there.
Since you stated that you could not find the intake for that return duct, would it have been a remote chance that this was a make up air duct for combustion? Not knowing where the house is and how old the system is.
Mosts openended ducts that close to the floor, that I have seen were make-up air. Just a thought.
I owned an old ranch house with forced air heat where the furnance sat on the slab foundation with the cold air return was butt-up to the craw space of the rest of the house. If you didn’t have a filter in place creatures could climb right in to the furnance from the craw space. Their was no cold air return ducts at all. The biggest hastle was that in the winter when you wanted a warm house. The house was o.k. until the furnance kicked on then the floor would turn ice cold to about a foot from the floor. The air never circulated in the winter.
Budget for replacement of the furnace as soon as possible, or alternatively throw the matter back onto the vendor with that famous quote; “replace furnace prior to closing of title/escrow” or "service furnace prior to closing of title /escrow … or budget for immediate replacement of furnace due to combustion/draft issues.
i actually thought of this when i first saw the system. but the ductwork didnt route directly back to the furnace. i should have tested to see if there was a draw when i fired it up.
i wish i had some photos. i dont bother with pictures, too much hassle and unnecessary. but im getting a new camera phone for these types of things i want to show you guys.