7 degree difference, any suggestions?

[timil]

Hello,

Hope all are doing well!

It has been a very busy past 2 months since moving in. We've gotten a lot of things taken care of by the builder, but there's one thing we still REALLY want taken care of.

Our master bedroom sits upstairs above the family room, and is about 15x15, has 2 small south facing windows, and 1 medium west facing window. The room also has a cathedral ceiling (v shaped, not vaulted). The temperature in this room is typically 7 degrees colder than the room immediately below it - even at nighttime. The room below it has lots of south-facing windows, so, daytime temperature difference isn't as surprising.

The house is all regulated by one thermostat, located on the wall between the kitchen and the family room. The master bedroom is fed by only 1 supply and 1 return duct. Though, the adjoining master BR walk-in closet has another supply, as does the master bathroom (both of which are 1/2 the size of the one in the MBR).

While the cold is quite frustrating, we're actually more worried about cooling the room - since heat rises.

Do you think an inducer fan in the supply duct would help? Would one also be needed in the return duct?

Any other suggestions?

I've been caulking up a storm around the trim of windows through-out the house. Blinds are going up in the next week or so... We tried closing the vents open in the basement to provide more airflow to the upstairs, but that didn't seem to help.

2nd floor (pretty close to final version):
http://www.albumtown.com/data/00b5d2692a781b6a9d3d1522c6e9d1ad/24574_p320975.jpg

1st floor (close to final version):
http://www.albumtown.com/data/00b5d2692a781b6a9d3d1522c6e9d1ad/24574_p318739.jpg

They supposedly did do load calculations, but couldn't run more duct to the MBR based on the floor plan I had made - not enough interior wall space to get another chase up to and down from that room... So, that was certainly my fault. Live and learn.

I know that they will need to do some additional work to make the right choice and configure it right - but, assuming the builder is not going to have them install any more ducts behind drywall, what might be some viable options that we might get the builder to pursue?

Thank you!
Tim

[fat bob]

Seven degrees colder upstairs means something is very wrong. I would tell the builder it's unacceptable especially for the master bedroom. Hard to tell what the problem is. Could be an insulation problem, duct sizing, duct leaks, a kinked duct.

[m kilgore]

On a two story house your always going to have a temperature difference between the two floors. Shouldn't be so high in heating. I think your right about it not cooling well at all.

A duct booster, in my experience will not do any good. I would guess that you needed a minimum of 2 heat runs in a room that large. You should have been told during the construction process that they needed more space to get ducts up to the room. If you were told and would not give up any space for it then I would say your SOL.

You have a large second floor which should have been zoned or had a second system. At this point we can't tell what might need to be done as we don't know duct sizing and how its installed. The only way to fix the problem is to get the amount of air to the room as called for. At this point it looks like somthing is going to need to be tore up to achieve this. There are no magic solutions to doing the job right.

[dash]

Properly designed and they will help your contractor design it ,with the proper info.,this booster can help.


http://www.fantech.net

Have your contrctor email them they'll want duct sizes cfmc required and ststic pressure of the duct going to that room.

[Xavier]

Correct and seal the duct work, then balance the system, because Booster Fans "REDUCE FLOW"!

[coolmen]

only after i looked over the system,design. first thing i do on this type of call is adjust the dampers.you must have dampers on a 2 story single zone system.after my balance ill check fan speed.what size pipe did they use for supply and return?a master bedroom of that size on a 2nd floor 2 6" supplys. 1 return high cathedral.no one likes to cut sheetrock in a new house BUT cut it straght and clean with a good sheetrocker youll never notice.how about packing out wall at the famly room corner by steps and drop a floor supply by tv master corner?you the designer/homeowner the builder and hvac co will get it figured out.dont wait to long. the sooner the repair the better youll feel
im just giving you some ideas to think about.
good luck

[dan sw fl]

Originally posted by m kilgore
On a two story house your always going to have a temperature difference between the two floors. Shouldn't be so high in heating.

A duct booster, in my experience will not do any good. I would guess that you needed a minimum of 2 heat runs in a room that large. You should have been told during the construction process that they needed more space to get ducts up to the room.

The only way to fix the problem is to get the amount of air to the room as called ...

Guessing:
One 6" duct may currently be delivering 80 CFM.

Like M Kilgore states: ".. need 2 heat runs in a room that large".

Generally, a 15' x 15' ( 225 S.F.) room
would need about 150 CFM.

150 CFM or a little more might be achievable in one 6" duct with a FanTech in-line booster fan as recommended by Dash.

Is this the easiest, most-feasible
and Appropriate remedy?

Without zoning in a two-story house that size,
4'F differential might be considered 'fair' performance.

[propmanage]

A booster fan will only steel from peter to pay for Paul. You need to have some one check to see if the system was sized right. Then you need the system balanced right. If you find out the size is right and you are just not delivering the proper CFM to this room then you can ask for more suggestions. Otherwise its just one big guess.

[docholiday]

I also agree with blancing but ultimately if the duct work is marginal, you may have to correct that. I would not accept a "Booster Fan" in a new house.

[markco]

Check and see if during construction, somebody might have stuffed insulation into the return to keep debris out. Have seen this happen many times.

[pstu]

It would seem regrettable to need a booster fan to deliver enough airflow to a room, but that looks like a consequence of not designing the system to good (professional) standards. I know from reading hundreds of messages that Dash would be the first to suggest you need a Manual D type of design for your ductwork to know what you *should* have. I'm right, aren't I Dash? It is my opinion that if Dash says a Fantech product will help your problem, then it will. I have looked over the specs of some Fantech products and they are stout machines delivering a lot of airflow using a high static pressure. Powerful stuff.

At the same time I must agree with some other guys. Propmanage says "A booster fan will only steal from peter to pay for Paul." He is right, but that's what you want and need in a case like this. I too might object to a booster fan in a new house, but your house may be too far along to change that. I hope not.

Your forced air system will only carry so many BTUs per CFM airflow. A room with higher heat/cool needs simply needs more CFM one way or another -- unless you have a second system which is not forced air, e.g. 1000W space heater or window unit AC.

There's an outside chance you can modify the heat gain or loss in the problem room and change its needs. Is there an opportunity to install better windows if they aren't already in place? Or some kind of shading for summer heat gain? In my own master bedroom some window "solar screens" made a very noticeable improvement -- but some may say there is an aesthetic problem. You be the judge of that.

If it's not too late, find a way to route more ductwork to that problem room. If it is too late, then heed Dash's advice and get such an add-on to the original duct system. Heck, get Dash himself or someone like him if available where you live! When and if you get adequate airflow, then you can have the window types and sizes you really want.

Best of luck -- Pstu

[timil]

Lots of good advice - I feel much more informed.

Unfortunately, the house is done, and the builder isn't likely to re-run anything up through walls... But, we'll see how bad the problem is as summer approaches...

I looked and looked in the basement and could not find anything that looks like a register control (or anything else) that might control a damper. I did completely close the vents in the basement, and closed 2 others on the main floor. Last night the temperature difference was only 2 degrees. However, it was a mild night, with little wind -- we'll see as it drops to cold temps again in the next week or two.

Thanks for all the advice, I'll be in a better position to negotiate with the builder and to make a better decision.
Tim

[coolmen]

the dampers should be located at the elbow or coller above the duct where each supply connects.closeing off registers does not do much.it needs to be dampered at the main supply trunk for the best results.damper adjustements may be the easyest and cheapest solution to your problem.

[sweatinintx]

I had almost the same problem,but in a ONE story home.Master bdrm was always 7 degrees warmer than the rest of the house.Did it all, insulated curtains,black out curtain,electronic thermostat,had the entire system gone over......still warmer in the bedroom. Finally, a REAL AC company came out,and installed a larger plenium for the entire system,WITH restrictor plates in all ducts.Then,they ran a seperate duct JUST for the bedroom {an 8"} and restricted flow to the front of the house,which was freezing. They did all this work for $245.00!!! I had already blown in 30 inches of insulation in the attic,so that was never the problem.I even considered a "split system" {a mitsubishi Mr. Slim} for just that room at a cost of 2,000.00. NOW, my home is cool thru out,temp is set at 73 degrees and my elec. bill is never over $250.00!!! The larger plenum and a seperate,NOT shared duct solved the problem,for less than $300.00!!

[propmanage]

Every system needs to be balanced

[dash]

Originally posted by sweatinintx
I had almost the same problem,but in a ONE story home.Master bdrm was always 7 degrees warmer than the rest of the house.Did it all, insulated curtains,black out curtain,electronic thermostat,had the entire system gone over......still warmer in the bedroom. Finally, a REAL AC company came out,and installed a larger plenium for the entire system,WITH restrictor plates in all ducts.Then,they ran a seperate duct JUST for the bedroom {an 8"} and restricted flow to the front of the house,which was freezing. They did all this work for $245.00!!! I had already blown in 30 inches of insulation in the attic,so that was never the problem.I even considered a "split system" {a mitsubishi Mr. Slim} for just that room at a cost of 2,000.00. NOW, my home is cool thru out,temp is set at 73 degrees and my elec. bill is never over $250.00!!! The larger plenum and a seperate,NOT shared duct solved the problem,for less than $300.00!!


Althiugh the duct changes were needed,the money spent on insulation ,wasn't a waste,IMHO.


Great that you found someone that knew what to do!

[sweatinintx]

I have a friend thats an insulation contractor and is in attics literally every day of his life.I have no idea about the rest of the US,but "ridge vents" simply do NOT offer much help in SE Texas. They are fine in theory,but just not much help here. I didnt mention in my first post, I had also added 4 whirly bird turbines in the roof, and opted for two 1050 cfm solar powered attic fans as well. I also installed a continous soffet vent on the east side of the house to allow a "flow". I have to clean the dust and debris every two weeks from the screens,so I KNOW the house is breathing.My efforts may seem "overkill" to many,but you have to realize what weather I am up against. Humidity averages 83% yearly,temps exceed 93 degrees 6 months out of the year. We use our AC literally 11 months a year!! My home is brick except for the East wall and trim around the house. My next step is Hardyboard 2" off the current wall.and pack that airspace with as much insulation as I can and replace the tar paper thru out the attic ceiling and walls.As long as my elec. bills are around 250.00 in SUMMER and my neighbors are $600.00, I know I'm on the right track!