Home>Discussions>YOUR HOME>Seasonal Upkeep>Cold air through heating ducts
12 posts / 0 new
Last post
Michael1013
Cold air through heating ducts

My furnace is located in the basement where it is always cool (around 55)even in summer. The problem is the cold air from the basement comes through the duct work up into the living space. What can I do to prevent the air movement? I thought about building an insulated room around the furnace. What size? How to vent?
Thank You for any information

I live in Pennsylvania

canuk
Re: Cold air through heating ducts
Michael1013 wrote:

The problem is the cold air from the basement comes through the duct work up into the living space. What can I do to prevent the air movement?

Curious ..... can you elaborate as to how cold air is being circulated through the furnace?

Quote:

I thought about building an insulated room around the furnace. What size? How to vent?

This idea can be problematic and dangerous .... really shouldn't be considered.

Blue RidgeParkway
Re: Cold air through heating ducts

mabe insulating your duct work and the sill plate of the basement to cut down on drafts is a better choise.

Michael1013
Re: Cold air through heating ducts

The air is entring through the vents on the furnace and then into the ducts. I figure the air is either moving through natural convection with cold air moving to warm air, or maybe there is some kind of pressure difference.

Thank You

Blue RidgeParkway
Re: Cold air through heating ducts

i'd check the chimney and the heat exchanger.

canuk
Re: Cold air through heating ducts

Hmmm ... that is curious. Warm air is less dense than cold air therefore warm air will rise. Cold air being more dense will settle downward and is less likely to flow upward through unasisted convection.
I would have to think the air must be entering from the cold air supply part of the furnace.

Is this something hat you are experiencin currenly or only during the winter ?

Do you have a fresh air intake line attached to the cold air return at the furnace?

Michael1013
Re: Cold air through heating ducts

No there is no intake. This is an on going problem. It was 86 degrees outside today, but inside the house the temp was 72. If I put my hand by the register, I can feel the cold air coming out. I don't understand why the air is traveling the way it is.

Thank you

canuk
Re: Cold air through heating ducts

Yep ... that is unusual.
Somehow air is being forced up into the furnace air supply plenum.

I suspect it is likely coming in the cold air return plenum and passed the blower to the supply plenum .... how or why ????

You might try using a smoke test to see where the air is going into the furnace.
An incense stick can be used for this.

I doubt it's a cracked heat exchanger .... it would have to have a gapping hole for the amount of air to flow that you are feeling.

Blue RidgeParkway
Re: Cold air through heating ducts
Michael1013 wrote:

No there is no intake. This is an on going problem. It was 86 degrees outside today, but inside the house the temp was 72. If I put my hand by the register, I can feel the cold air coming out. I don't understand why the air is traveling the way it is.

Thank you

i'd guess that since it is 86 outside and 72 inside and as you say the basement where the furnace is is even cooler there wouldn't be any reason for the furnace to fire. the fan is prolly running and circulating the naturally cooler air in the basement through the house. maybe you have a central air conditioner and it is running if you have a/c you should have a switch somewhere to change the thermostat from heat to cool mode. you should also have a switch to change from auto to on for the fan mode.

if you were complaining about cold air coming from the registers in winter you should know that even when the furnace fires it is normal to get cool air first blowing from the ducts until the hot air warms them up and starts blowing through and that the fan should only be in auto mode in the winter so that the furnace can delay the fan from start blowing until the burner runs or the element heats enough to heat the air before it starts blowing through the ducts or else you'll get a much longer blast of cooler air and have cool air blowing between furnace fire/heat cycles.

Blue RidgeParkway
Re: Cold air through heating ducts

do you have open windows or doors to the basement? did you change out the thermostat upstairs?

Pages

TV Listings

Find TV listings for This Old House and Ask This Old House in your area.