Latest Discussions : HVAC


09:13PM | 05/18/11
Member Since: 05/18/11
2 lifetime posts
This is a challenge. Last year we moved into a house with a living room with a 45 degree vaulted ceiling that opens up to the upstairs landing where the bedrooms are located. The house has a 2 year old geothermal heat pump that is in perfect working order. Winter utilities in Missouri $600/mo for 4200 sq/ft. Summer utilities $300. Vaulted ceiling has knotty pine tongue and groove attached directly to ceiling rafters with only fiberglass batting on top and exposed to the open attic space. Upstairs is always cold while downstairs is warm. There is strong, cold draft flowing in through poorly installed gas fireplace on main level, but if the upstairs was really sealed, the upper level would be much warmer than the lower level. Also, cold air can't rush in through fireplace unless air is leaking out somewhere else just as fast, causing negative pressure. Sorry, I'm a physics major. Obviously the heat is leaking out upstairs and drawing air in through the fireplace. I have had insulation experts, fireplace experts and contractors here to figure out best option. Obviously, I need to fix fireplace leaks. But, what is best option to stop air loss through pine ceiling. Option 1: remove fiberglass, add vapor barrier over pine on attic side and spray closed cell foam to create air seal, then blow in cellulose. Insulation pro says that will probably work but be major pain in the backside as well as expensive. Option 2: put vapor barrier on the room side of the old pine, then either tongue and grove foam with taped seams or sheet rock over the pine to create air seal, and install new layer of knotty pine to restore that rustic look that we love.

Option 2 will actually be easier, less messy and cheaper according to contractor and insulation guy. I can live with that as long as we stop the air loss and maintain the rustic knotty pine ceiling that made us fall in love with the house in the first place.

Question: What are the pitfalls or either option 1 or option 2? Do we create any unanticipated moisture problems with either option? Is there a better option. Why on earth don't builders drywall the ceiling properly, then install the pine boards, just like when you add wainscot to a wall. I think they are just cheapskates or stupid, or both.

As it stands right now. As you walk up the stairs, it is like a reverse thermocline. Half way up, your head enters the cold layer and by the time you get to the top, you are cold head to toe. Open floor plans that are sealed well are usually too hot upstairs when the main level is just right. What else can we do?

By the way, we are having an EPA high efficiency wood fireplace installed in place of the old gas fireplace, and they will address any air leaks via the chase/flue. The house was built in 1991, has premium windows with no major draft issues and the panes are barely cool to the touch when it is 10 degrees outside. I think we will fix the fire place then have a blower study with Infrared imaging done just to make sure that the ceiling is the culprit. If it is, how would you fix it? Help!!!!!


12:54PM | 02/09/13
Hello, Hope this is not too late !

Apart from the horizontal glass bats, you don't say how else the loft space is treated ABOVE the leaky ceiling. I presume it is insulated on the roof-slopes ! If it is NOT, then it ought to be ! In addition your horiozontal insulation needs to be thick enough, and boarded over if you place stuff in your loft (don't compress the glass...).

Then, you just leave your leaky ceiling as it is (easy solution!). The air you are heating with your precious dollars will end up in the LOFT. Just make sure it does not get out into the SKY ! Then install a downcomer pipe in the loft, as big as you can manage (5" PVC, for example) and PUMP the warm air as far DOWN as you can get it in your house (preferably into the basement), and just let it flow out into a mass (such as bricks, 3" stones etc.) to make a HOT BED. The heat will then escape by natural convection, and find its way around the house, & up the stairs etc. so it will not be lost.

Stay warm,

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