Heat falls?

Old 01-24-03, 11:04 AM
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Red face Heat falls?

Hello! We have a 6 year old townhome with 3 upstairs bedrooms. Master bedroom has cathedral ceiling, rest of bedroom flat 8 foot ceilings. There is a 'normal' stairway with no large downstairs to upstairs open foyers. There is an unfinished, uninsulated basement with forced-air HVAC.

In the winter time - the upstairs is always freezing. The middle level of our home is warm and the basement is cool. The attic is fully insulated - looks like builder-supplied R30. This morning the middle level was 69 degrees - our bedroom was 57!

How can heat in our home fall and cold air rise?!? Would adding additional insulation to the attic help?

Any advise would be helpful!

Thanks - Glen
Old 01-24-03, 10:13 PM
bungalow jeff
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Sounds like the system is not balanced, so most of the heat is pumped to the first floor.
Old 01-25-03, 08:44 AM
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First try to determine if you are getting adequate heat supply to the master bedroom. Take a tissue paper and put it up against the supply register and compare it with the supply registers in the rest of the house. Next locate the return vents in the master bedroom, if there is one and put the tissue paper near the vent. The tissue paper should be drawn to the vent. If the master bedroom cools fairly well in the summer, the return vents will probably be high on the wall. You may want to tape a thermostat one foot above the return vent and wait 5 minutes to record the temperature. Do the same below the return vent.

Another concern with cathedral ceilings is that all heating systems do is heat volumes of air in the home. So when we say that our home is large and that's why my heating bill is too, we're basically saying there is more air to heat in my home than others. Furniture and other household goods displace air in the home. If you take a glass of water that's full and drop marbles into it, the water flows out of the top of the glass. The more marbles you put in, the less water there is in the glass. The marbles represent the furnishing in the home and the water the air. But there are no furnishings on the cathedral ceiling, unlike at the floor in most rooms. This nearly doubles the amount of air in a room with cathedral ceilings in comparison to rooms with 8 feet high ceilings. Even though the volume of air in a cathedral ceiling room is only 50% more. Keep this in mind when discussing this with someone that may be balancing your system. You require considerably more heat to this room in comparison to a room with 8 ft. high ceiling.

There are other concerns with cathedral ceiling rooms when it comes to obtaining desired temperatures such as recess lighting and skylights. Beside increasing the heat demand for the room dramatically, it usually cuts the life of the roof in half. But they look nice.
Old 01-25-03, 11:55 AM
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Thank you for the replies. I think one of the problems is that there are no return vents in any of the bedrooms. There is only one per floor: one at the foot of the top of the stairs (up high near the ceiling) and another on the first floor at the bottom of the stairs. (down low by the floor)

I noticed this week also (since its been soooo cold out!) that our master bath vents (not HVAC but the vents above the toilet and shower) have cold air coming through them to the inside. We've since been closing the master bath door to see what would happen and the temperature has gone up. (Not equal to downstairs, but at least it's better!).

I'll have do the tissue paper test to see if the vents are equally blowing throughout the house.

Thank you again for your time!

Old 02-01-03, 02:38 AM
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I think you can solve your problem by keeping simple. Just remember, heat rises. If your upstairs is too cool, not enough heat is rising and getting into your room. Now, it may be going irght up past you and into the top of your catherdral ceiling. In which case you might need a ceiling fan to blow it back down.
Also, your house might not be warm enough to get the upstairs warm. The warm air should be coming up your stairway. Also do you have a floor vent from downstairs right up into your bedroom ? Just a open and close vent in the floor ? Good Luck
Old 02-01-03, 04:33 PM
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Heat rises

I agree with Jack in keeping it simple. Heat does rise. Cold air sinks. A ceiling fan switched to circulate downward in the cathedral ceiling of the bedroom will be helpful. I have lived in houses where there was a simple grate placed in the floor of an upstairs room to allow the heat from the room below to rise into the room above. Cathedral ceilings tend to collect warm air. Pushing it back down with a fan would be very helpful. Keeping all bedroom doors and vents open so you have proper circulation is also important.

If you want to check to see if you have adequate insulation, go to http://www.doityourself.com/insulate/ where you can calculate your required R-value for your ZIP.

Of course, you can always add electric baseboard heat that you can turn on and off as needed to supplement when it is cold. I have electric baseboard heat at my mountain cabin. I leave it on the lowest setting when I am not there to keep pipes from freezing. When I am there during cold weather, I always keep a fire going.

You might also investigate if the builders installed the correct 'size' unit to heat and cool your home and to make sure that all duct work is properly installed and vents/dampers are open. Also, locate the interior units and make sure you change the filters on a frequent basis. In conversations with HVAC repair persons, I frequently hear the stories about folks who call because systems are not working properly and filters have never been changed.

Keep us posted on your progress in resolving your heating problems. How goes it in the summer time? When I lived in Tidewater Virginia, many homes had separate units to heat/cool the upstairs. The only room I had trouble with was the 'bonus room' built over the garage. It was freezing in winter (probably lacked insulation in garage ceiling) and sweltering in summer. This room should have had its own unit because it was located at the far end of the house over the garage and away from the central unit.

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