Heat/AC trickles on main level, blows hard downstairs, 1966 house

13 years ago

Hi, I'm looking for some advice prior to calling a HVAC person. It likely will take expertise to fix this, but I want to do some homework to avoid overpaying.

We noticed this summer that the central AC was blowing weak upstairs. A summer of high electric bills didn't quite drive it home that there might be a problem. Now it's cold and the heat is doing the same thing.

The house is a 1960s ranch with a full basement. HVAC is downstairs, ducts come out from the furnace. We can see the ones going to our bedroom and bathroom in the unfinished part of the basement, but the rest are hidden by the downstairs family room ceiling.

Heat and air blow HARD out of the downstairs family room vent, just as hard as we remember. It will blow your hair around and you can feel it blowing down on you when you sit in a specific chair about 5 feet away. Upstairs is just a trickle, it's so weak in all the upstairs rooms.

The system has 7 registers upstairs, 1 or 2 downstairs, 1 intake on each level. We just changed the air filter even though it wasn't too bad. 4 cats in the house, so changing it often is a must. I looked for a damper on the one main branch I can see going to our bedroom and bathroom and I saw a screw or something sticking out, but I'm not sure if that's for a damper.

Any thoughts on this?

Sort by:Oldest

Comments (7)

earthworm
13 years ago
The circuit damper must be closed, or nearly closed.
Have a good HVAC MAN examine the ducts, they may need to be cleaned.
I may be facing the same thing.
A pet peeve... A house and a car are the same, either must have a repair manual, yet these are pitched, or never existed..
Now, its costly to find this damper or "hot air valve"..
Where this screw is protruding, you may have the damper, you should see the damper flap shaft ends.
Hope this helps.
theresas
Original Author
13 years ago
Hmm I think we do have the manual from the previous owners. And you may be right about having the ducts cleaned. We had someone clean them back in '05 when moved in here. The previous owners of the house (all 4 of them trailing back to the 60s) were smokers.

Circuit damper. Ouch, yes, this sounds like could really cost us. We have some weird little tube that always collects water in the winter and we have to drain it. Something else happened with the unit that my husband was able to fix on his own as well, but it sounds like it's definitely time to call in a pro. We didn't have one out here last year to give it a good cleaning and inspection either.

My fingers are crossed--maybe my cousin's dad will take pity on me and drive up here and help me or tell me if he has a HVAC friend who lives in my area. Now that the expressway has been extended, he could be here with about 45 mins of travel time, but I'm sure he's busy out the wazoo now that cold weather is here.

We've been trying to keep the thermostat down around 65 or 66 and just use a space heater when we're in the living room or let the warmth of cooking keep us going when we're in the kitchen. Bedroom has a nice thick comforter keeping us toasty. Still, I want our mechanicals functioning even if we can keep up with our frugal, sweater-wearing ways this year.
Related Discussions
ac system for new home build
Q
Comments (16)
Ionized, Thanks for the suggestion. I thought about calling Fujitsu to see if internally blocking one of the vents would void the warranty. Just haven't gotten around to doing it yet. I also feel bad for one of my dogs who sleeps on the floor across from the foot of the bed. She would then be getting even more air. As it is she often creeps off to sleep at the doorway out of the draft. Our other dog sleeps on the bed. Usually he likes to stay down by our feet but with the AC going he will keep moving up till he is even with our heads. We don't keep it very cold. It is set at 76 at night to keep it from coming on too much. But at any temperature when it blows it blows cold and creates a draft. Your right in that maybe an installer who could have installed the unit in the attic and run the ducts would have avoided this situation. But no one in our area had any experience with that particular unit nor were they interested in doing it. As it was I was struggling to find anyone who had experience with these at all. And yes we are very happy with the units. Cooling power is unbelievable and the cost is very low to run them. Zoning is amazing. Every area can be set differently and turned on and off as needed. No issue cooling an area down immediately. Plus virtually no noise outside. I can hear the neighbors units and not ours at all. Were on 1 acre lots so the neighbors aren't that close but their ACs are noisy compared to ours. We also have the redundancy with the heating system due to the heat pump functionality in the AC. Could be very valuable if on a cold day our heat system goes out for some reason. This would keep the radiant heating piping from freezing. I think the main issue with this type of system is the initial cost vs. central air when you already have ducting. With no ducts we didn't have a choice. Eventually we will work through the bedroom draft issue even if we have to buy a canopy bed. Some folks with central air can't cool their bedroom at all so I think most systems have their pros and cons. Ionized, since you have had both can you compare the operating costs for mini-split vs. central air? I'm curious to know if it is cheaper with mini-split. I think we expected the worst so have been pleased that there is very little cost to operating the system but were coming from using a swamp cooler so don't don't have a point of comparison with what it would have been vs. central AC. In terms of the point about the aesthetics. With a new build you could completely hide the system. We looked at several options that hide the units in the attic or the wall and you get just traditional looking vents. The only thing that prevented us from doing this was a lack of an installer to take it on. It is called the Slim Duct. Here is a link. Here is a link that might be useful: Fujitsu Halycon System
...See More
Carrier Infinity Heat Pump & AC Quote in northern VA
Q
Comments (40)
12" return is almost definitely too large for the basement. I have a 6" return in my basement, and I have actually found it to draw ~200-240 cfm (using a barometer) -- plenty in my case with just a few supply outlets. In your case, I have no way of knowing for sure, but I assume it's piped directly (or near) to the inlet of the furnace blower compartment, in which case there is a lot of pressure and it's sucking in a lot of air and making the basement quite negative (not a good thing). So your basement return in that state may have been drawing close to, if not more than, half of the return air the entire system requires. Is the basement floorplan open to the rest of the home or closed off? If typically closed off, I wouldn't be surprised if the basement door had a tendency to close itself when the system was operating. I suppose putting cardboard over half of the grille is one way to reduce its intake capacity. Your older furnace does not (presumably) have a variable speed blower that will vary its RPM in order to maintain a specific CFM setting. That means that while you are noticing more airflow from the rest of the returns throughout the home, in totality your system is receiving less airflow -- no, not a good thing considering your ductwork is likely undersized to begin with. You have decreased its return capacity. To get the SAME (total) airflow from the rest of the returns throughout the home that were not previously drawing as much air generally requires the system to operate at an increased static; with older PSC type blower motors (non variable-speed), this results in decreased airflow. Hence variable speed motors are often termed "constant CFM" as they can adjust (increase) their speed to maintain a constant airflow (cfm) when subjected to as much as 0.8-1.0" of external static pressure (vs. conventional blowers max. of 0.5", which many duct systems are nowhere close to achieving despite it being the standard "design" figure). You can think of the ESP number as a measure of resistance to airflow, in a sense. The fact that you say the (supply?) ductwork is now much warmer is both concerning and telling. It is unwise for me to say much more than that as I am not there to evaluate your system design and give an accurate assessment of the ductwork design/layout, etc. But it suffices to say, with the info you've provided us, your return ductwork is now more restrictive, which would exacerbate any existing airflow issues. You do say it met the set point without tripping the high limit. Please let us know how the system performs as it gets colder out and the system runs more often in its present state. I would like to ask what made you consider replacing the systems (and proceeding to get 8 proposals) in the first place? Are there functional problems with the existing equipment (besides most likely being oversized) or other comfort issues? By now we have at least established that it is likely the existing equipment is a bit oversized and the existing ductwork is marginal -- but that is (unfortunately) exceedingly common on most residential construction. Are you after more efficiency, better comfort, both? It helps us to help you when we know more about your current system's performance. Lastly, I would not factor online reviews into your decision too much. An air conditioner or furnace is not like most appliances (such as a refrigerator) in that the installation practices and quality can make or break even the best equipment selection. There is a good chance that many (but not all) of the negative reviews you read were due to installation errors. This post was edited by ryanhughes on Fri, Nov 22, 13 at 9:51
...See More
New HVAC systems - Equalize upstairs/downstairs temps and quiet
Q
Comments (13)
However, if the AC is running to cool the upstairs down to 75, the downstairs will be between 65-68 degrees. There are two systems in this house, but they each do both the upstairs and downstairs on opposite sides of the house. Only the system for the main living area has AC. It is a 16 SEER Carrier. We are looking to replace all the heating and AC units and want to achieve these goals Equalize the temp between upstairs and downstairs Quiet the noise, both of the AC and also the heating/fan Improve efficiency How would this best be accomplished? It's better when you separate floors and use 1 HVAC system to cool upstairs and the other HVAC system to cool the lower floor. Because heat rises and cooling falls that lower level unseparated from the cooling system will always be too cool. You have two systems so it would be best to separate those to heat and cool one level / not a mixture of two levels. It sounds like this might be challenging due to cathedral ceilings and your disdain for spending money with the notation that these ductwork changes can't be done for <$30K. So you're at the point of letting the structure defeat you? Certainly I can understand why, it's not uncommon to find a line in the sand --- a line you won't cross no matter what. If that's the case, sell the "box" and buy a different one. Some homes are a challenge for more reasons than one. Cathedral ceilings, large walls of glass look oh so pretty... you get a mountain view (probably for your Colorado home) but once the heat comes that view gets distorted. Builders do all sorts of things to sell homes, you don't realize the downsides to what they do until you try to live there. ----------------- By separating these areas and zoning the upper floor to the upper floor and zoning the lower floor to the lower floor... how does that work? If you're not calling on the lower level there is no cooling. If the upper level is calling only that area is getting the cooling. Cool air will fall to the lower level but this amount will be much less than supply duct work blowing air down there. I service the Katy, Texas area.
...See More
How hard is it to add a zone to an A/C system (Lennox iHarmony)
Q
Comments (7)
Thoughts on whether it is a good idea to push for the extra zone up here? I can't think of any downsides. The more thermostats you have, the better the control of the system. Given the variable aspects of the condenser if implemented properly can work very well. The bad news... Lennox variable speed AC as well as the furnace is designed around Lennox's "communication" protocols in order to operate this system as designed. If the Iharmony zoning has an option to use "regular run of the mill" thermostats -- of which I seriously doubt --- because communicating relies on thermostat input and is different from a regular "off the shelf" thermostat. Maybe the installer wasn't quite sure of this... a salesman often sells things erroneously. I think you should press them to do the job as quoted. However, you may find this won't be possible. Communication type systems are proprietary signals from all things attached to the system in question. Proprietary means: This system will "always" need a thermostat from Lennox to operate this system... in some cases these systems can be converted back to legacy controls (meaning a regular off the shelf thermostat) --- but in most cases this turns your variable speed AC into a less than variable AC. In some cases a lowly two speed AC condenser. I put in a couple of communication based systems in the past (around 6 years ago) so I am ahead of the curve in how most of these work / what you can / what you shouldn't mix with them to get them to perform as designed. At that time there was nothing better... so people who wanted something better chose them. (That was then, this is now to help you understand how things change over time.) Due to the "communication protocol" of the system chosen you then also have to choose a proprietary zone system to relay that communication around the system -- furnace and outdoor condenser. So you will always be bound to this communication problem. All the big manufacturers Lennox, Trane, Am. Stnd., Carrier, Daikin/ Amana do things this way. It's one way to do it --- they all chose to do it similar ways but proprietary to their brand. Daikin / Amana appear to be changing with comfort bridge technology the communication stuff is in the furnace, this maybe relayed in some fashion to the condenser usually via a two wire communication from furnace to AC condenser. The Bosch Inverter, a marvel in it's own right does things differently. It doesn't rely on proprietary anything to run. I like to consider them a disruptive technology to beat up the big behemoths that seem more interested in keeping control over you and how their systems function. So because the Bosch Inverter operates this way gives freedom to use other zoning options that are better, not to mention less costly. It may be too late for you to consider Bosch so this reference is mostly for those who might stumble across this thread later on... weeks, months and some cases years into the future... looking for comparisions in the AC inverter realm. I service the Katy, Texas area. So I did a quick check. It is as I say.... click to enlarge if necessary.
...See More
earthworm
13 years ago
Sorry, but another peeve.Manuals are not well written, much info data is missing...Lets hope that the manual has a schematic, at least of the duct work...If not,... I can see why so many pitch them.
Bad news is the smoke damage.
IMO, the cleaning and inspection ,every 5 years should suffice, but this is a guess.. My ducts....maybe never, but no AC either.. The system works OK.
We were in a house a few days ago that was heated with a kerosene-stove.
Amazing heat, and rather clean.

I think that you should be able to find the damper, in the meantime, try closing the other one and see if this helps.
theresas
Original Author
13 years ago
Technical writers are woefully under-employed in all fields!

We didn't find the manual for the heater, found most of the others that we filed when we moved in here. And finding a schematic on line for our furnace, Armstrong Air Ultra V Advantage 93.

Last winter we had to empty some tube that kept filling up with water, a pressure valve I believe, because the heater would stop firing when the water was full. We'd take a cup and pull the plastic hose off, let it drain into the cup and put the clearish plastic hose back on.

Now my husband is finding another hose full of water, and it seems to be leading back to our humidifier, an Aprilaire 550. We've never (I know, I'm ashamed to admit it) done anything to service the humidifier or change the filter. This weekend we will spend some time reading up on the proper care and maintenance of the humidifier, including how to change the water panel evaporator (he just came upstairs saying those words--Google help me!)

He's looking for some way to identify the circuit damper. There is no error code with the lights, they are blinking "normal." Slow and deliberate. We'll figure this out and learn along the way. In the meantime, we're spot-heating with our little electric woodstove-style fireplace. 'Tis cold in our neck of the woods tonight!

If we need it, the heat will work. It just doesn't blow worth anything upstairs and now that we think about past performance, the downstairs vent doesn't blast us anymore when we sit in the chair near it. The heater runs for several minutes, kicks off for a short time, then does it again. Then we're at the temp set on the thermostat and good to go for awhile.

Horribly inefficient. This is why our cooling bills were outrageous. I still cannot believe that we didn't figure this out in the summer.
ziggyhere
13 years ago
Close off the registers in the basement so more air will push upstairs. Inexpensive. If this works, you can look into electronic damper systems that automatically open and close.

A humidifier has a water panel in it that needs to be changed annually. If you don't you could possibly flood your basement.
theresas
Original Author
13 years ago
We changed the water panel today, easy, painless. I downloaded the manual for our Aprilaire Friday and got the part number and instructions. Man, I never thought about the possibility of a flood. We're trying to become less clueless. I know we probably sound pretty bad. It's good to learn how to do these things in a DIY capacity and also to know when to call a pro.

Today my husband took the blower out of the furnace to gain access and got in and vacuumed the coils. It really wasn't too dirty in there. I just asked him to close the two vents downstairs to see if it helps up here. They're all on the same ductwork as the upstairs one. We have one central shaft that goes the length of the house right under our main floor, which of course is the basement ceiling.

Well well well. Heater just kicked on and that helped. Much better airflow!

Now I thought I had read a few people say that shutting off registers was a bad thing? These two downstairs ones are right there on the main shaft, in the middle of the house, not the arms going out to the sides of the house where all the upstairs vents are. Most of our upstairs registers are under windows around the perimeter of the house (not very wide, think double wide trailer, that's the dimensions of our house.

We'll look into an electronic damper system--thank you earthworm and ziggyhere for your suggestions! I can't tell you how happy I am to have some closure on this issue!
david1948
13 years ago
You also might remove the heat registers and look for blockage in the ducts using a mirror and flashlight.
Dave

Heat/AC trickles on main level, blows hard downstairs, 1966 house

Comments (7)

earthworm

theresas
Original Author

Related Discussions

earthworm

theresas
Original Author

ziggyhere

theresas
Original Author

david1948

COMPANY

BUSINESS SERVICES

GET HELP

CONNECT WITH US

Heat/AC trickles on main level, blows hard downstairs, 1966 house

Comments (7)

earthworm

theresasOriginal Author

Related Discussions

earthworm

theresasOriginal Author

ziggyhere

theresasOriginal Author

david1948

COMPANY

BUSINESS SERVICES

GET HELP

CONNECT WITH US

theresas
Original Author

theresas
Original Author

theresas
Original Author