Installing storm windows; getting rid of fumes from an oil furnace

Q We'd like to install storm windows next to the existing 7 1/2-foot-high screening on our 42-lineal-foot, L-shaped porch, which faces south and east. The existing posts are not designed to accommodate storm windows, however. Does the screen prevent solar heat transmission? Would it be better to have the new glass panels inside or outside the screen? We'd like to have removable storm-glass panels. How does rigid plastic compare with glass as to heat transmission? Pamela Dunn, Middletown, Conn.

The screening would inhibit solar-heat transmission only a little.

Install the new storm panels where they can be most readily mounted with minimum carpentry, be that inside or outside the screening.

A carpenter could tell you how best to do the job by an on-site inspection.

There are many qualities, kinds, and thicknesses of rigid plastic used on porches. As a heat transmitter, glass is superior to almost any plastic.

Plastic has reasonable longevity, but may fade, again depending on the quality, color, and thickness.

Were the porch mine, I'd install a permanent or fixed wainscot the first 2 1/ 2 or 3 feet from the floor.

It could be of the same material as the existing exterior walls. That would reduce the number or size of the new storm-window units and make installations and removals simpler.

Q A new oil furnace, installed under our house in 1977 after the old one caught on fire, continues to emit oil fumes into the house. The fumes, however, disappear after the furnace has been running for an hour or so. The installing company says the furnace is working properly and that the fumes come from the ductwork because of the earlier fire. The fumes are not apparent when the air conditioner is in use. What can we do? A reader, Charleston, S.C.

I would agree with the opinion of the installer that the oil-fume problem is in the ductwork.

If the ducts are suspended below a wood-joist flooring system, it should not be too difficult or expensive to replace or clean up the troublesome areas. Oil must be spilled or leaking inside the supply air duct or plenum. Has anyone investigated these areas?

If the ducts are underground below a concrete slab, access to them is more difficult and expensive. Nevertheless, they need to be exposed to find and correct the oil spillage or leak.

In any event, the fuming must be stopped. There is no other place to stop the fumes than where they are. Obviously, they are not in the furnace itself. This assumes that the pipe carrying the oil has been inspected and found to be sound from tank to furnace.

After the actual oil residue has been eliminated - wherever it is - if some fumes remain after a month or so, you may want to install Odor Control System Y 495, made by Honeywell, 1885 Douglas Drive North, Minneapolis, Minn. 55422.

The unit controls disagreeable odors by evaporating a small amount of counteractant odor into the air. The fragrance interacts with the odor to neutralize it, lending only a faint trace of fragrance.

To determine if the Y495 unit might counteract the present oil fumes, get in touch with Honeywell. The phone number is (612) 870-5200.

If all else fails, contact a professional firm listed in the Yellow Pages under ''Deodorizing & Disinfecting.''