Heating, Air Conditioning, Fridge, HVAC/residential ducts and venting


Hello. Moms house was bought in 2005,built in 1995. The house has central air/heat. The furnace is propane fueled. There are vents in floors near windows. There is a vent on BOTTOM of wall near floor in front room. It is long almost 3 ft with no means to close or open that I can see. I put my hand there and feel cold air. I dont undertand why there are no cold air ducts at the top of any wall in any room. I have looked in every room of house(ranch style with basement)on main floor. There is at least one floor vent for heat that can open or close. Also in each room a metal vent on bottom of wall that cant be closed. There is also about one foot above floor on wall a vent that can be closed about 6 feet from front door in foyer. I am trying to reduce drafts and heat home with minimal use of central heat,as electricity has been cheaper that propane. I have one small forced air space heater at end of front door foyer facing open front room( the front room, dining area, kitchen,laundry room,and hall way to 3 bedroom are all connected with no doors only walls of various sizes. At opposite of front room under window and near floor heat vent I plsced a radiant oil filled radiator type space heater-a Delonghi EW7507EB. Please advice about cold air felt at unadjustable wall vent in front room(bottom-all vents on walls at bottom of wall) Is it normal to feel cold air at those vents at bottom of walls. ALSO--do you think placement of spaceheaters correct,and do you like oil-filled radiant as compared to electric elements and fan type heaters. Thank you very much for your help and reply!!!!!

Generally speaking any vent that can't be open or closed is a return and anything that can be opened or closed is a supply.  There are also different ways to design and install systems.  Sometimes the vents can be near the floor or ceiling or both.  There are also free and ducted returns to the furnace.  I can not say for sure what kind of system was installed without checking things out myself. There might be a combination of ducted and free returns in the home.  You can take some tissue paper or something of the like and see if it is drawn in to a vent with the furnace fan running to determine if it is a ducted or free return.  Just make sure the doors are open inside while testing in case you have free returns to stop the air from passing though.  Sealing up the vents with painters tape might help in some cases stop drafts.  DO NOT tape up any ducted returns and then turn on the system.

The type of space heater is just a matter of taste.  I can not say which is better.  


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Craig HVAC Expert


I have been in the HVAC field for the past 18 years. I can help with most HVAC questions. I work on commerical buildings for the most part, and have yet to find anything I could not troubleshoot and repair, when repairable. I work on small 1 ton units to a 2500 ton chiller. Troubleshoot air flow, elect, and control problems. I attend regular classes to keep up with the latest and greatest.


I work on commerical sites, hospitals, gov't buildings. I can troubleshoot just about anything in the HVAC business.

5 years trade school, VFD training classes, Liebert factory training, some York and Trane factory training.

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