need help current system

[loudog2]

I live in a 3-story townhouse(end unit), including a finished basement, in the chicago suburbs. The sqft is about 1850+700(basement). Three fourths of the basement is above ground. I have 20ft. ceilings in my living room, 9ft in familyroom and kitchen. Upstairs there are 2 bedrooms and 2 baths. My front faces east, side south and rear west.

There are 16 supply and 3 returns. The current furnace is a 75,000 btu hiel single stage w/a 3 ton blower and a 10 seer 2.5 ton a/c. The calculated heat loss is 74,000 btu's.

My question is what can I do to improve this system, which is only four years old. The a/c stuggles in the summer, the upstairs is always warm. And the heat struggles in the winter, rooms are cold.

The walls are 2x6. Would a 80 or 100,000 2 stage variable w/a 4 ton blower help? I'm assuming the more powerful blower will help circulate the air, and suck more air back into the system. I don't know why the builder put only 3 returns in. I want to save energy and make the house more comfortable, and get rid of the temperature swings in each room.

I narrowed it down to trane and lennox. I'm looking at the 80% and 90% 2 stage variable efficiency ones.

[Irascible]

Originally posted by loudog2
I narrowed it down to trane and lennox.There are a lot of issues in your post. However, that sentence is the biggest problem IMO.

If your existing equipment is wrong for the house then it was a contractor (or architect or whatever) that picked wrong. If the equipment is right but installed wrong then that too was a contractor. Even if it's the house itself (improperly installed insulation or whatever) then that too was a human failing.

The point I'm beating to death is that the improvements you seek will come by way of a contractor, not a brand. Trane and Lennox are great. But as with any brand, there are a lot of bad Trane and Lennox dealers out there. Conversely, there are precious few truly competent HVAC contractors (in my opinion). Limit yourself to those two brands and you may miss the best contractor.

Seek the best contractor. Virtually any major brand has the equipment you need. In fact, the equipment brand is almost incidental.

[Irascible]

As for the technical side of things: If at all possible have a zone system installed. The lack of one in addition to poorly designed ducts is your biggest problem IMO. And believe me, a properly designed and installed zone/duct system is a rare thing indeed. It's the contractor that makes or breaks a zone system. Trane or Lennox won't help you on that front. :)

Keep reading. I've got some good links in my sig. The more you know and the more questions you ask your prospective contractor, the more you're going to scare off the hacks.

[loudog2]

I trust the two contractors I mentioned. One is a trane and one is a lennox. I've had both to my house in the past, and so have my family and nieghbors.

I can't have a zone system. My association(townhouse) rules will not allow it.

Would switching from a 3 ton blower in the furnace, to a 4 ton blower help? Both said that the 2.5 ton a/c is fine. They think it is a circulation problem with only 3 returns(2 down, 1 up). They both also said the furnace was borderline small(75,000btu).

[jim baughman]

Originally posted by loudog2


I can't have a zone system. My association(townhouse) rules will not allow it.

.

never heard of that one before. How would they even know what you have for ducts?

[cheoelleon]

I am going to recommend the basics. First determine the design load of the amount of living space required to be conditioned.(usually done on a manual"j" form i believe) Ask the local supply house whats a rule of thumb ratio in your area between square footage of house per cubic foot of air. This ratio will vary in relation to each floor as well whether in cool or heat mode. The ratio you expressed is approx. 1850 + 700 = 2550sq.ft. per 3 tons of air. Thus 2550/3=850 sq.ft. per ton. This sounds to be undersized. But then I doubt that 2550 is the actual conditioned space. Without actually seeing the house I cant offer much more than advice thats minimally invasive. The unit blower is designed for 3 tons of air as well as the duct. An increase in volume of air is proportional to increase in pressure and energy demands. So I actually would'nt jump to the blower idea right off the bat.
You can run the indoor fan continuously 24/7 which will increase circulation in the home, decrease energy consumption and keep the air cleaner. Also an electrical engineer will confirm an electric motor uses less energy running than when starting. You will need to keep the properly sized filter grilles changed more often. I do recommend a certified test and balance company to perform a test and document the duct performance. This will tell alot about what is happening inside that system. ALSO CHECK THE RETURN & SUPPLY TEMPERATURES TO VERIFY WITH THE EQUIPMENT MFG. THAT IT IS OPERATING AT THE OPTIMAL RANGE. SO SORRY YOUR STRUGGLING WITH THIS ISSUE.

[iheatncoolinnc]

A zone control system would use the existing or new heating and air conditioing units. Dampers could be placed in the ducts going to the diferent levels of your home. Thermostats on the different levels would control the system and the dampers. You would put the heating and cooling where it was needed instead of everywhere in the house. The neighbors would not know the difference between this system and a single zone system since the outside appearance is the exact same. Now, will the existing ducting work with a zone control system? Only someone in your area with an excellent knowledge of zone control could tell you this. How accessible are your ducts? Can some changes be made to the ducting? A larger furnace might not be more comfortable. You stated it was warmer upstairs. I assume you would like for it to be warmer on the lower levels in the winter. This means without some ductwork or zoning, the upstairs will be even hotter to get the lower levels where you want them. If the whole house is cold in the winter, and the system runs nonstop, then a larger furnace could help. Good Luck with your comfort.

[loudog2]

Originally posted by jim baughman

Originally posted by loudog2


I can't have a zone system. My association(townhouse) rules will not allow it.

.

never heard of that one before. How would they even know what you have for ducts?
Sorry. I thought you meant two furnaces and two a/c's, like in larger houses, one for up and one for down. Actually the rooms upstairs are cold in the winter and hot in the summer.
I'll talk to the contractor about zone control. If I have it runing all day(fan), then I guess a variable speed will be better?

Thank you all for your help. I now have alot more questions to ask the contractor.

[Irascible]

Have you already talked to your contractors about this loudog?

The need for extra returns is true if you wish to increase total system airflow (http://hphaa.com/services/installation/installation.htm#Return_ducts) or deal with pressurization issues (http://hphaa.com/services/installation/installation.htm#typical_home). However, barring those two important items an extra return is not key to solving balance issues.

Outside of zoning, the real key to comfort is proper air mixing. That's achieved by getting proper exit velocity from good quality diffusers (http://hphaa.com/services/installation/installation.htm#diffusers). For example: If you have fast moving, unobstructed air coming out of floor vents in summer then that cold air will head straight up, bump the ceiling and create a circular current that will even things out. It works similarly if you have floor or sidewall vents as well.

Returns on the other hand have virtually no effect on air mixing. They're just a drain. Think of when you were a kid and you watched a floater at the end of the bath tub. It would move very slowly until it got right up to the vortex. The same is true of a return. Just a few inches off the return the air velocity in most systems is negligible compared to that of a supply vent.

Running the fan 24/7 can indeed be helpful. Or it might be a complete waste that costs you more and makes the air dirtier. There's no one pat answer. Just as there's no one pat answer to AC sizing. I wouldn't waste my time talking to a wholesaler about rules of thumb.

[cheoelleon]

was long enough. However since I have the whole weekend off.... lol. You are exactly right about pressure issues and air flow returning back to the intake grille. The amount of returns need'nt exceed the amount that serve each level as long as the air can escape under doors and such to reach the return "drain" as he states. Thats the important part. I only recommended a supply house manager with some good knowledge to draw from for an unbias formula, for a quick idea on what he might be looking at cost. A rough "square footage vs cfm " rule of thumb will help established a resonable amount of air volume demanded in the home. Thats not to be suprising information from a man who has hvac contractors in his establishment daily. The bad systems do usually come back to haunt the poorly educated and trained installation team. Things to consider are frequency that rooms are used? Does the whole building need to be comfortable 24/7? Also, do not become concerned so much with the amount of grilles placed within the dwelling. Walls, floors, or ceilings that have a controlled climate on one side and the outdoor temperatures on the other are of primary concern. Anything out of the ordinary such as "sun rooms" are extra demand on the system. Look for "weak" spots in your homes insulation armour. The existing system may be sized properly? Then this becomes an installation error. As with any project the first boundary set is the financial budget. Other than that, you will need to have an engineer with hands on knowledge in the field to inspect the existing system. (Since, "honest & reliable" contractors are hard to find.)Also, as another costly option you can obtain a Test & Balance Report from an independent company that doesnt install hvac. NEBB is one example of who certifies members to perform these tests.

[loudog2]

I plan on asking a lot more questions once I get a chance. I had to work lastnight and tonight. I will call him first thing tuesday. I am actually waiting for my association to give approval for the 94% furnace, since they would use PVC out the side of the house.
I appreciate the help. I usually do alot of things around the house myself. But I'll admitt, I know little about hvac.

[seatonheating]

Originally posted by loudog2
I plan on asking a lot more questions once I get a chance. I had to work lastnight and tonight. I will call him first thing tuesday. I am actually waiting for my association to give approval for the 94% furnace, since they would use PVC out the side of the house.
I appreciate the help. I usually do alot of things around the house myself. But I'll admitt, I know little about hvac.


Another reason why I would never buy one of those "cookie cutter" tract homes. Asking for permission to make improvements on a home you pay mortgage and taxes on....ridiculous!!

[loudog2]

Originally posted by seatonheating

Originally posted by loudog2
I plan on asking a lot more questions once I get a chance. I had to work lastnight and tonight. I will call him first thing tuesday. I am actually waiting for my association to give approval for the 94% furnace, since they would use PVC out the side of the house.
I appreciate the help. I usually do alot of things around the house myself. But I'll admitt, I know little about hvac.


Another reason why I would never buy one of those "cookie cutter" tract homes. Asking for permission to make improvements on a home you pay mortgage and taxes on....ridiculous!!
Sorry! I bought the townhouse when I was 25 years old(didn't want to rent). I guess you had a lot more money at my age, and got yourself a nice house. Good for you!!

[Edited by loudog2 on 09-02-2006 at 02:07 PM]

[tinner73]

what town are you in?

[loudog2]

I live in St. Charles, IL.

[tinner73]

Originally posted by seatonheating

Originally posted by loudog2
I plan on asking a lot more questions once I get a chance. I had to work lastnight and tonight. I will call him first thing tuesday. I am actually waiting for my association to give approval for the 94% furnace, since they would use PVC out the side of the house.
I appreciate the help. I usually do alot of things around the house myself. But I'll admitt, I know little about hvac.


Another reason why I would never buy one of those "cookie cutter" tract homes. Asking for permission to make improvements on a home you pay mortgage and taxes on....ridiculous!!

i'd bet my next paycheck you couldn't afford a 4 year old "cookie cutter" home in St. Charles Il.;)
http://realtor.com/FindHome/HomeListing.asp?snum=53&frm=bymap&nearbyZp=&lid=Enter+MLS+ID&pgnum=6&ss_aywr=&st=IL&mls=xmls&mnbed=0&js=on&mnsqft=2000&fid=so&vtsort=&poe=realtor&mnprice=0&ct=st%2E+charles&zp=&primaryZp=&mxprice=99999999&typ=2&exft=iaoh05&exft=0&exft=0&exft=0&mnbath=0&areaid=92733&sid=073357B04D1EC&snumxlid=1066491944&lnksrc=00002

[tinner73]

loud...it sounds to me like you have an airflow problem. lack of return. replacing the equipment might not necessarily be the answer, although it does sound borderline on sizing. bigger equipment will probably need bigger ductwork. i'm in Schaumburg, my email address is in my profile, if you'd like another opinion.