Pour circulation for heating and cooling.

[66stang]

I live in a two story house and the upstairs is either hot in the summer or cold in the winter. I have already increased the size of the blower motor in the furnance from 1/4HP to 1/3HP. with no noticible affect.

So now I'm thinking of adding in-line duct fans, would this make a difference?

How far away from the vent of main line should it put the duct fan?

I'm also curious as to how to run the power lines up to the duct fans?

 

Thanks for any and all help.

66stang

 

 

[Crouching Tiger]

I would start by checking the insulation in the attic.  Attics can account for 20-25% air leakage.  Poor insulation up there will result in heat loss in the winter and heat gain in the summer.  I have a century home and in the winter when the roof is covered with snow you can see sections of melted snow where the heat is escaping because of inadequate insulation. 

[66stang]

CT, thanks for the reply. the house was built in '96 and I've seen the insulation and believe it you be sufficient. I also did not see any kinks in the duct work.

[Guest ahammer48]

Hello. Just increasing the HP of ur motor dosen't mean ur moving more air. Whats the difference between a 1/3 hp turning @ 1750 RPM and a 1/4 hp @1750 RPM? Nothing. The 1/3 is just sronger and has more torque. In order to move more air you have to change RPM on the blower.

If you have direct drive(mtr is directly attached to the blower wheel) theres not a whole lot you can do, except to check that the highest speed of that mtr (Assuming its is a multi-speed mtr) is being used. Most of todays units come with multi-speed fan mtrs. Usually 3- speed mtrs. Look @ ur mtr or wiring diagram. It will tell U. You maybe on med spd for cooling and low spd for heat when U really need Hi spd

If you have fan belt drive and theres a non-adjustable pulley on the mtr you can change it out to a varible pitch drive pulley that allows U 2 change the RPM @ the blower.

Has the upstairs always been a problem or over the yrs its gottn worse?? Sometimes installers will put a filter grill in the wall not realizing that theres a filter installed in the unit. I'd check that and do a couple of  other checks before I start messing with fan speed though.

[applianceman18007260692]

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[lucyLiu]

Hi, I know this is an older thread, but I have a poor circulation issue that's not answered by these helpful replies.

My house is over 40 years old, and we have central air; the furnace is upstairs.  Of course the upstairs tends to be warmer in the summer heat and cooler in winter and I'm not so much conerned about that.  Extra insulation and a new roof were installed just prior to us moving in about three years ago. What IS puzzling is why the downstairs front room is the same way but the rest of the downstairs is not.

Had to cut a hole in the ceiling to correct a plumbing leak and found among other horrors that there is WIND blowing between the framing when the fan runs. Getting into the attic (it's a Cape Cod-style home) is a real bear and will leave me red and itchy for weeks but I'm willing to do it if my uneducated guess is right that some of the ductwork to the front room's two old-fashioned round ceiling vents may have been dislodged.  I can't see anything for sure from the access points, as everything is buried under insulation.  It would mean crawling on my tummy in insulaton for about 60 feet to find out.

May I humbly ask if my theory might be correct, and if not, what else might I consider?  It seems also that surfaces collect fine grey dust remarkably quickly even by dry & windy Texas standards.

When you get done laughing at my silly question I appreciate any suggestions.

 

 

[dkpd1581]

If everything is burried under insulation, and according to your earlier post it is more than sufficient, one might think that it would attenuate or muffle any air flow from the blower motor.  Is there no doubt whatsoever that the "wind" you feel is from the blower.

Is it a positive pressure from the supply side of the system or could you be feeling return air making its way back to the airhandler through some unintendended path.  Make sure the air movement that you notice is truely related to your lack of air flow in certain areas of the house and understand what its proper place in the equation is.

In a worse case scenario, you could opt to use a smoke bomb to check the duct lines for leaks.  It will most certainly let you know where the leaks are.  We use it in commercial applications; however, it is during test and balance, everything is still exposed/accessible, and there is no occupancy.  Since this is your home, it not a first choice.

No matter what you do, you will have to expose the duct runs which means you will have to get into the insulation.  You could have broken duct, poor duct design, poor installation.  A 40 yoa house may have add on duct that the system was never designed to carry.  It will be a hands and eyes on affair. 

Sorry no magic bullet or easy clean solution.

[lucyLiu]

Thank you for the speedy reply! I will put on the coveralls and get myself up in there before it gets too hot and look for breaks to put back together. This is about all I can do, being woefully ignorant of what parts are what.  I was working on a spot to the right of and within a few feet of the vent with the strongest airflow in the house. The problem room is to the right of the hole and about 25 feet away and the air was flowing towards the powerful vent.  If that helps any!

There is a unit outside I assumed was the condenser and also a large thing upstairs (assumed a furnace and also makes cold air, the filter is at the bottom and I DO change that regularly!)  This ancient thing is entirely wrapped in silvery insulation so I have no idea what brand or model it could be.  The only thing sticking out of the wrapping is a lever to direct more air up or downstairs depending on the season (is this not the blower? If so, it's pretty close to where I was making the hole).  :? 

Given how many unexplainable stupid things we have already found that were the work of the previous owner, a DIY-er who seems to never have thought of calling in a profesisonal for anything no matter how beyond his ability, there is no telling what I might find.  The registers in the back rooms of the home and the upstairs are the more modern rectangle ones and the front of the house has the older circle-kind so who knows what was added or changed over the years or if it was a pig's-ear from the get-go!

Thanks agin...if my odyssey in the insulation helps the situation I'll be sure to post.