Heating, Air Conditioning, Fridge, HVAC/home heating - two story


Hi John,

Just wondering what the best way is to try and ballance out the heating in our two level home.  We usually run 8-12 degrees colder in the lower level. (of course it's always difficult in the summer to keep the upper level cooler  than the lower too)

Both floors have almost the identical floor plan. However the lower level has round vents in the ceiling and the upper level has rectangle vents in the floor.  Upper level has plenty of windows facing south, west, and east.  Lower level has a couple south windows.  most of teh n,s, and west walls are mostly under ground level.

The upper level has cold air returns in each bedroom and two retuns in the hallway that i suppose service the rest of the upper level.

The lower level has cold air returns in two rooms, but does not have one in the finished laundry / storage area where the furnace is located.  Additionally, in the exact same square footage as upstairs that is serviced by two cold air returns, there is only one cold air return.

Lastly, there is a solid core wood door that seperates the front entry way from the lower level.

I've tried partially closing vents upstairs and opening the lower level vents all the way.  This doesn't seem to make any difference.

Of course the thermostat is located in the upper level and the lower level is completely finished accept for the ceiling in the room where the furnace is located, so I'm guessing I can't incorporate dual zone heating which would have been a really good idea when the original owners finished it off.

Any suggestions would certainly be appreciated, especially from the two that are fortunate enough to have those bedrooms downstairs!!!  :)

Thank you!

 One of my " pet pieves " that two story ( 2 zone ) homes should be set up that way.  Either with 2 systems, which is best, or duct work that is made for zoning.
 Unfortunately, in your case, it is not only imptacticle to even think about zoning, but because, they do not have the lower floor under the house and the upper floor in the attic, seperating the 2 is not possible.
 Shutting down vents to move the air elsewhere not only does not work ( as you found out ) but it actually can damage equipment and makes the heating and/or cooling sourse work harder and less efficient.  Air does not act like a fluid (water) in that shutting off openings in one place increases pressure in the main line and in the other openings.
 Just the reverse is true.  You see, as air flows through a duct system it pushes out in a 360 degree circle including backwards twords the sourse.  But most important it pushes out sideways in a circle all the way around the duct.  It is called static pressure, and it slows the flow of air every inch along the way.  ( If you took all the air in your system and put in down a great big 4 foot by 4 foot duct, afew feet away from the sourse it would blow hard.  But if you added more lenght to that duct, say 100 feet without a single turn, the air coming out the end would barely be felt at the end )
 So, you can turn the fan switch on the thermostat from auto to ON and let it run all the time and keep all vents open and the door open from the top and lower floor.  That will at least let the air EVEN out a little by constantly moving it and make a small difference from the upper and lower spread of temperature difference.  Next put a reversible fan in the stairway from upper to lower level and move the air twords the level that needs it the most, it should be one way in heating and the other in cooling.
 For the cooling season you should also put a pwer exhaust fan in the attic so the temperature difference from the upper floor to the attic is not as great and the heat will not enter the upper floor as bad as it does now.  2 things cause heat to transfer....the amount of R value (insulation) and the temperature difference.  The higher the difference from the attic the more it will enter the top floor and make the difference from upper to lower even greater, so conversley the lower the TD from the attic to the upper, the lower the TD from the upper to the lower floor.
 Physics doesn't allow for the same to be true in the winter, so without adding a lot of money into the structure about all else you could do is install a couple small electric (wall) or area heaters or small free standing gas stove type heaters.
 The inbetween expense type thing before re-doing everything you have now is to put a ductless heat pump in with a couple heads both down and up to suppliment for each season.  That would run you 5 or 6 grand, so cheaper than re-doing everything but not cheap period.
 Hope this helps a little.  Sorry I don't have a magic answer, but I think you kinda know the boat you are in. So.............BUILDERS that might be reading this.  PLEASE, put the correct duct and heating /cooling system in when doing the home in the first place, because it is an expensive pain in the a.. to fix it after the fact.

Heating, Air Conditioning, Fridge, HVAC

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john t. borgman


I am in Portland Oregon at Ben's heating 503-233-1779. I work days, so I can only answer early in the day or later in the evening. I only answer public questions for residential equipment. I am very well versed in gas, electric and heat pumps and will only answer residential applications. I have been known the past decade or so, by my employers as the guy you send when no one can figure it out. Trouble shooting is my special. I understand the physics behind air flow, refrigerants and electricity. I understand programmable t-stats, zone controls, economizers, fossil fuel kits and the engineering thought process in the wiring and construction of residential equipment


I was lucky enough to start in this field almost 30 years ago as an installer, for a company that installed the best duct systems I have ever seen, even to this day. The best ,as far as understanding the way air really flows through a duct system, from the return air to the very last supply register . They also had great pride and the duct work was put in, not only to last 50 years, but to look exceptional. Then as I started doing service work, I was again fortunate that I found a 3 year engineering class being put on be a man that was the educational director for the Entire united states for a society called " the Refrigeration Service Engineering Society " And for the next 3 years I schooled at night and practiced what I learned during the day, a great advantage over schooling and then trying to remember it years later.. Versed in duct design manual J heat gain/loss calculations.

Refrigeration Service Engineer's Society

I have 2 inventions that have gone through the process and been recorded at the National Institute of Standards and Technology from start to finish and thus been invited to national innovation workshops by the dept. of Commerce and the dept. of Energy. They are waste heat recovery devices that N.I.S.T approved as valid and am currently looking for marketing partners to get this product into the hands of consumers and make a BIG difference in Energy savings for every Household and Eatery and take a big bite in the the peak hours power consumption that face our Utilities companies.

factory training in Lennox ,Rheem, Ruud ,Trane, Tempstar ,Carrier, Day&Night, Payne, Bryant, Coleman, Intertherm, York, Goodman, Ultra boilers, Unico, Mitsubishi,Sanyo, Taylor, Nicewonger, Navien. Associates degree in Refrigeration Engineering. Certified with Energy Department, Check-me Program, P.T.C.S (performance tested comfort systems ), have N.A.T.E. certifications in gas, a/c & heat pump.

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