2nd floor doesn't cool enough

[cabriggs]

I have central air and while the first floor gets comfortably cool, the second floor doesn't. My house is a two-story colonial with basement and attic in northern Massachusetts. The vents for the first floor are in the floor and come from the basement. The vents for the second floor are in the ceiling and come from the attic. Putting my hand up near a second floor vent, I can feel cool air coming out at what seems like ok pressure (my uneducated guess).

Now it seems to me that there are probably several factors at work here. One is that the cool air coming out of the second floor vents goes under the doors and down the stairs. To combat this, I got some of those bead-filled "snakes" (or whatever you call them) to block the space under the door. I also hung a curtain across the hall at the top of the stairs. Together these things seem to help a little, but not nearly enough.

Another aspect of the problem is that it seems like not enough hot air is being removed from the second floor. There's a return vent in the second floor ceiling and it's about 1 sq. ft. The return vent in the floor of the first floor, however, is about twice the size and seems to pull in much more air than the second floor return does. The first floor return is practically right on top of the furnace, less than 5 ft. away.

Where the main vent comes out of the top of the furnace, it splits into two, one for each floor. In the one that goes to the first floor, there's a lever. The two ends are marked open and shut and it's variable in between. When I set it to shut, it seems like the air pressure coming out of the first floor vents is a little less, but I can't make any kind of accurate measurement.

Also, I don't know if this is related, but today I noticed a little water on the floor near the furnace. Should I be worried?

Back to the main question: what kinds of things can be done in a case like this? (I'm not looking to DIY--this clearly isn't my area of expertise.) Am I more likely to be happy calling a professional or just getting a couple of window units for the second floor rooms I use the most? If I call a professional, what are they likely to do and what do I want them to do? Is zoning the answer?

Let me know if you need more info, of course. Thanks for any advice.

-cb

[karsthuntr]

A pro should be able to zone your house with little trouble. Zoning is probally the best way to take care of your problem.
Call a pro and get an estimate, make that three and hire the one you like the most, cheap is not always good.

[dash]

Where are the return grilles located?

Unless the 2nd floor rooms have rturns,blocking the space under the door ,will prevent air from going into the room.No air return,no supply.



The dampers where it splits are there to adjust air,summer=more to second floor,winter less,opposite for first floor.These dampers may need repair,the handle could have slipped,and open ,may not be open.


Zoning as mentioned is the best so;lution,If you have proper return ducts and grilles.

[cabriggs]

Originally posted by dash
Where are the return grilles located?

Unless the 2nd floor rooms have rturns,blocking the space under the door ,will prevent air from going into the room.No air return,no supply.

There's one return vent for each floor -- for the first floor it's in the floor of the living room (which spans the front half of the house) and is roughly 2'x1', and for the second floor it's in the ceiling of the hallway and is roughly 1'x1'.

After trying blocking under the door it occured to me that air flow would be a problem.

The dampers where it splits are there to adjust air,summer=more to second floor,winter less,opposite for first floor.These dampers may need repair,the handle could have slipped,and open ,may not be open.


Zoning as mentioned is the best so;lution,If you have proper return ducts and grilles.

It didn't occur to me that the damper could be broken. Like I said, I can barely detect a difference in air flow to the first floor when I change it, but then I'm using the lowest-tech measuring device around--my hands.

So what's involved in zoning anyway? How do they actually do it?

Thanks.

-cb

[airworx]

zoning works of of a controller that takes readings from sensors in each zone, as the zones warm the controller modulates a damper for that zone as the zone cools the controller closes it. depending on how many zones depends on
how many dampes and sensors. 2 zones would have two dampers and two sensors. sensors can be senors or themostats which has sensors.

[cabriggs]

Thanks for the info. Next question.

So I want to get some quotes. I understand if I have someone come out and they do a real diagnosis on the system, take air flow measurements, etc., that I may have to pay $100-200. I don't have a problem with that.

But in the general case of trying to get a contractor, one talks to a few contractors and gets a few quotes. When the quotes are free that's easy, but in this case they're not. How do people get multiple quotes for HVAC work without sacrificing several fees?

I realize most of them will waive the fee if you have them do the work, but if I get three quotes I'll have to suck up two fees. I'd like not to.

How do people handle this?

Thanks.

-cb

[docholiday]

First off zoning is one solution but not the only solution.

You can have seasonal balancing damper installed which may be your lowest cost solution. The draw back is that you will need to move them to a predetermined position when going from winter to summer and visa-versa. This should not be a major cost.

Zoning may work well but often times it may mean some fairly drastic changes in the overall duct system to make it work correctly. If improperly done it can create more problems than it overcomes including early equipment failure with shortend lifespan. However, if installed properly it can be a real answer to prayer.

As for getting a handfull of quotes, you can probably anticipate some fees as the contractors know from experience that generally what you are looking for is price. Contractors often know the design and installation is critical and they also know there is always someone who will imply they can do it for much less and get the same results. They cannot jeoprdize the integrity of what they propose just to compete with low priced competitors.

You may consider having a mechanical engineer or design consultant design a system for a hefty fee and offering the specified job up for bid. This way the design is not the factor in the different bids. Good luck finding a contractor who will share his design for free.