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-   -   Tennessee contractors? TXV replacement (http://www.diychatroom.com/f17/tennessee-contractors-txv-replacement-23842/)

Faulknertw 07-17-2008 07:41 PM

Tennessee contractors? TXV replacement
 
OK, it's still me with the same issues as related below: http://www.diychatroom.com/images/misc/paperclip.gif http://www.diychatroom.com/images/misc/subscribed.gif Carrier rep coming to diagnose a problem . 8 Ball wants to know if a Tennessee contractor will tell us if the photos in the above thread constitute a normal HVAC installation in Tennessee.

BTW, they replaced the TXV today and it made absolutely no difference at all. The system ran all day nonstop (and is still runnning) and the temperature in the house has risen to 76, despite the setpoint being at 72.

I know I'm beginning to sound like a broken record but everyday it is not fixed costs me about $3 extra dollars in my electric bill based on the increase last month.

If I hire a different company to come out and diagnose the problem, do a Manual J load calc, etc., can the company that installed the system say the warranty is voided? I assume the new HVAC people would have to check pressures, etc. I am at the point where it would be worth $100 to find out definitively what the problem is. And, realisitcally, would the company that originally installed the system even listen to what a separate company found?

Thanks again

coolmen 07-17-2008 07:58 PM

go to hvac talk.com and pay 50 to do a load calc your self. I will walk you through it cause i use that pro gram every day. all so draw a diagram of the exact duct layout to incude size registers , size duct and lenth. to all so incude how many registers and returns and most imortant where are these returns located.with a complet duct layout for use all to see would be very helpfull.draw out a house plan photo copy and so we all can see. you MUST double check the load befor trying to fix any thing

8 Ball 07-17-2008 10:48 PM

Coolmen is right. Get a print of the house from the GC, and do the calculation. Existing ductwork, at the moment is irelevant. Windows,wall thickness, insulation ceiling height are all more important at this point.

Getting another contractor, would seem to be premature, at least until your sure of exactly what the problem is. Ask again for a copy of the original contractors load calc. Dont be suprised if he cant come up with it.

From my experience, working for GCs, theres not a lot of money to be made by subcontractors. Get in, get done, get gone is the only way to make money. Trust me, I doubt anyones got the cash to fix your problem, let alone admit a mistake was made.

Again, Coolmen was right, square one. If you know of and trust another HVAC contractor in your area, or have worked with one in the past, they can do the load calc., the rules dont change just because your in Tenessee.

wire_twister 07-18-2008 11:30 PM

I have a 2200 sqft single story house with 8 foot ceilings except in greatroom where they are 13 feet. The house has 2x6 exterior walls with r-19 in the walls, r-30 in attic and r-13 under floor. My hvac man did the manual J calc and installed a 5 ton unit in the house. It cools very well even on our many 100+ degree Georgia days.

coolmen 07-19-2008 09:10 AM

Quote:

Originally Posted by wire_twister (Post 140605)
I have a 2200 sqft single story house with 8 foot ceilings except in greatroom where they are 13 feet. The house has 2x6 exterior walls with r-19 in the walls, r-30 in attic and r-13 under floor. My hvac man did the manual J calc and installed a 5 ton unit in the house. It cools very well even on our many 100+ degree Georgia days.

Here in the north east(jersey) depending on the window and orientation of the house, rough guess but probally 3.5 to 4 tons. does your unit cycle on and off alot?

1610 CUB 07-19-2008 02:25 PM

I'm new here, but wen we looked at a house the formula is 1 CFM per SQ/FT.
You need 400 CFM per ton of cooling.
so SQ/FT = 2500 divided by 400 CFM = 6.25 Tones. For the whole house.

coolmen 07-19-2008 10:22 PM

Quote:

Originally Posted by 1610 CUB (Post 140773)
I'm new here, but wen we looked at a house the formula is 1 CFM per SQ/FT.
You need 400 CFM per ton of cooling.
so SQ/FT = 2500 divided by 400 CFM = 6.25 Tones. For the whole house.

The manuel J load calculation is the only way.To use your formula is a HACKS way of doing things. I assure you that a 2500 sq 1950 built house. compared to a house built of todays standards are not even close of being the same. better yet a house built in vermont and a house built in arizona will be totally differant size a/c. 2500 sq house with 6 tons cooling (2400 CFM)will sound like a jet engine.VERY loud. people seem to think that because you have central cooling your suppose to hear it.bottom line is do a load calculation. It takes me about 2 hours to do. 1 hour of inspecting and measuring the house and 1 hour on the computer. So easy to do.

1610 CUB 07-20-2008 10:32 AM

Quote:

Originally Posted by coolmen (Post 140881)
The manual J load calculation is the only way.

Tell this old tinner WHAT the answer is? While my numbers are not 'true' to the j manual they do heat & cool people in their homes nicely. But I've been away from it about 10 years

geo fan 07-20-2008 11:51 AM

load calc.
 
the simple fact is different classes of people have different expectations of there heating and cooling systems. The more money you have for some reason the less you want to even know its there. If you are of the working class you want to feel the air blowing and to hear a slight noise. These are steriotypes I know but for the most part true and my company will take cust. preference into the sizing of the system. When you consider that everytime you do a full heatload calc. you round up depending on what part of the country 8/10 the square foot rule works out to the same size unit. You realy just have to know , this house has 15 foot cielings very tight construction and a wall of windows on the south, maybe just maybe a heatload calc is required. I dont know about you guys but new construction its required to show on you mech. prints the btu/cfm for each room in order to pull a permit. So its only an issue on retro.

geo fan 07-20-2008 11:59 AM

you dont have to call the guy a hack. I know Im one to talk but your point is just as valid without the insult. For all you know this guy's workmenship would blow you out of the water . I dont know him from adam but none of us know it all. and 10 years ago it wasnt common practice even in comercial

coolmen 07-21-2008 06:48 AM

Quote:

Originally Posted by geo fan (Post 141056)
you dont have to call the guy a hack. I know Im one to talk but your point is just as valid without the insult. For all you know this guy's workmenship would blow you out of the water . I dont know him from adam but none of us know it all. and 10 years ago it wasnt common practice even in comercial

sorry if i hurt your feelings for useing the word HACK. my father and my brother,in business 40 years never ever used manuel J. they taught me how to do it with out a manuel J. My method at one time was to sqx8x5=heatload then divide to get a cool load. I am a big fan of load calc do to the fact that people want the most eff system installed. to do this you really need to do man j,man S.

geo fan 07-21-2008 03:18 PM

I agree
 
Im not insulted but the word hack to a blue collar guy is like the n word. I have seen it come to throwing bones over stuff like that. a proper heat load calc. is the right way for sure but to me a hack is somebody that knows that and doesnt care or even worse knows nothing. And you cant tell me that in a heat load calc. on a retrofit you dont guess and round up either. do you realy find out the true u rateing on the specific double pane window or do you use the number given in the program ( an average) do you tear open the walls to see what insulation was realy used or do you give a best guess. My point I guess is that even the company's doing calc's are going to round up. If what people want is the most eff dx geothermal's would be everywhere :)

1610 CUB 07-21-2008 03:54 PM

It does not take much to "pull the wool" over the eyes of the home owner. The salesman with his laptop
and a load calc can have the owner reeling.
1 Get an independent load calc done (that will keep all the players even)
2 My 2 cents All home owners and their family's like to hear & feel the HVAC at work.
3 The ducting will need changes also

Faulknertw 07-28-2008 08:05 PM

OK, round three. TXV replaced. No change. They replaced the coil last week. Now, on a moderately warm day (<90F) the system cycles well and does not run nonstop. Any warmer than that and it goes nonstop from 1100 until late at night jsut like it always did. I will hire a reputable HVAC company to do a Manual J, take it to the GC and HVAC installer and see what happens.
In the meanwhile, Carrier is going to come back with the HVAC installer to try to diagnose the problem again. From everything all of you have said, plus anyone around here that will listen to me, its a sizing issue. To small a unit for a house with this much air.
Another issue diagnosed by me: The cavity where the flex duct comes into the air return in the hallway has no insulation. The HVAC guy threw a few handfuls of insulation on top of the hole to "cap" it. Temps get hot in the attic and push down the cavity where the t-stat is located causing a higher reading, in turn keeping the unit running longer.


Thanks for all your help, everyone.

8 Ball 08-15-2008 07:44 PM

I would really like to know how this all turned out.


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