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Old 01-18-2018, 11:33 AM   #16
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Re: Duct opinions wanted


This is the labyrinth jungle gym the AH is installed in. I suspect the older installers want nothing to do with it? Off to the right you can see where the 180 is. I have asked a few if they see a way to relocate it and was told it does not seem practical.
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Old 01-18-2018, 11:45 AM   #17
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Re: Duct opinions wanted


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Originally Posted by jjrbus View Post
If I get loose with the #'s I come up with a bit over 2 ton.

Thanks for the response greatly appreciated.
Be as accurate as possible.

to properly estimate air leakage, you need a blower door test.

A question:

Did you old 2.5 ton cool properly and maintain setting? Did it cycle?

Because if it did, when air ducts are fixed and you get proper 400 cfm per ton, the delivered capacity will be closer to the machine's capacity.

You can potentially get the same amount of cooling you are now with a 2 ton.

If you stay with 2.5 ton and redo the air ducts for that capacity, your delivered cooling capacity will go up, you could end up with too much capacity and poor dehumidification.
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Old 01-18-2018, 12:58 PM   #18
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Re: Duct opinions wanted


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Originally Posted by jjrbus View Post
This is the labyrinth jungle gym the AH is installed in. I suspect the older installers want nothing to do with it? Off to the right you can see where the 180 is. I have asked a few if they see a way to relocate it and was told it does not seem practical.


" Looks like you need a Genie in a bottle or a Company with skinny apprentices"
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Old 01-18-2018, 03:17 PM   #19
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Re: Duct opinions wanted


Quote:
Originally Posted by user_12345a View Post
Be as accurate as possible.

to properly estimate air leakage, you need a blower door test.

A question:

Did you old 2.5 ton cool properly and maintain setting? Did it cycle?

Because if it did, when air ducts are fixed and you get proper 400 cfm per ton, the delivered capacity will be closer to the machine's capacity.

You can potentially get the same amount of cooling you are now with a 2 ton.

If you stay with 2.5 ton and redo the air ducts for that capacity, your delivered cooling capacity will go up, you could end up with too much capacity and poor dehumidification.
Was the 2 1/2 ton ok? Yes but, I seem to have 1 1/2 ton ducting, and the 2 rear bedrooms and bath were not cooling well, so I was only cooling 3/4 of the house, with diminished capacity.

If I mention 2 ton to any of the estimators I have had they tell me no way. Remembering that 7 of them have wanted to put in 3 ton!
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Old 01-18-2018, 03:23 PM   #20
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Re: Duct opinions wanted


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" Looks like you need a Genie in a bottle or a Company with skinny apprentices"
Need child labor laws revoked for a week
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Old 01-18-2018, 03:24 PM   #21
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Re: Duct opinions wanted


If 2.5 ton cooled fine with lousy air ducts and probably as low as 320 cfm per ton - barely enough to not freeze, a new 2 will likely deliver similar capacity with proper airflow, well insulated sealed ducts.

If the supply air is distributed evenly, the rear bedrooms will cool fine.

The "no way" is probably from experience with similar poorly done systems.

The delivered capacity can easily be 40% less than the rating in the field.

If airflow and wetbulb temp measurements were done at each register, airflow measured at return and heat removal calculated, in all likelyhood it would be falling well short of 2.5 tons delivered.

If the air flow is correct, the charge right, the ducts not leaking much, a smaller unit will go a longer way.

You need a performance oriented company that does load calculations, blower door tests and properly engineers the solutions proposed.

It will cost more up front but work a lot better with lower utility bills.

They may be hard to find. They need to be screened over the phone, no "tons per square ft" bs.

Quote:
Need child labor laws revoked for a week
They need to stop installing air ducts in unfinished hot attics when building houses.
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Old 01-18-2018, 03:57 PM   #22
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Re: Duct opinions wanted


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Originally Posted by Mikel7829 View Post
I am going to assume this is a fly by night contractor that is just working out of a van...There is to much flexing going on here..If this contractor can't fabricate his own duct would you not be willig to go with all duct board? Or maybe just snap lock? I'm guessing this design is the cheapest way out for you and the more this guy will profit for the job..Like was stated do a proper duct calculation the few extra
dollars you spend will be worth it, and alot less fewer headaches you will have in the future..IMO
" Hey how did you know the name of my Company? FBN HVAC/REFRIGERATION
Fly by night HVAC/ REFRIGERATION"
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Old 01-18-2018, 04:40 PM   #23
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Lol.. @COLDIRON
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Old 01-18-2018, 04:49 PM   #24
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Re: Duct opinions wanted


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Originally Posted by user_12345a View Post
If 2.5 ton cooled fine with lousy air ducts and probably as low as 320 cfm per ton - barely enough to not freeze, a new 2 will likely deliver similar capacity with proper airflow, well insulated sealed ducts.

If the supply air is distributed evenly, the rear bedrooms will cool fine.

The "no way" is probably from experience with similar poorly done systems.

The delivered capacity can easily be 40% less than the rating in the field.

If airflow and wetbulb temp measurements were done at each register, airflow measured at return and heat removal calculated, in all likelyhood it would be falling well short of 2.5 tons delivered.

If the air flow is correct, the charge right, the ducts not leaking much, a smaller unit will go a longer way.

You need a performance oriented company that does load calculations, blower door tests and properly engineers the solutions proposed.

It will cost more up front but work a lot better with lower utility bills.

They may be hard to find. They need to be screened over the phone, no "tons per square ft" bs.



They need to stop installing air ducts in unfinished hot attics when building houses.
I have found 1 contractor in this area that seems to know what he is doing, I talked too him and I am too far away from his home area, plus he is doing the million dollar homes in Naples.


I told him what I had run into and he referred me to a man that had trained with him for several years went off on his own and worked in my area. Got an appointment and he showed up, 3 ton's $4000! I told him I had concerns with the ducting, his response was we will put in the unit and if there is any issues with the duct we will deal with it then!

10 estimates is ridiculous, in Florida a manual J must be filed with the permit application. These people must be fudging the numbers.

So now I have a AC tech that has been a friends neighbor for over ten years, is honest, dependable, just not the best at duct design. Why can't I get some input on the design and use him?

Thanks for the feedback greatly appreciated.
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Old 01-18-2018, 06:27 PM   #25
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Re: Duct opinions wanted


Have you tried google locator map and homestars, if u have it.

Lots of contractors there - i would keep looking a little more before giving up.
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Old 01-19-2018, 06:11 AM   #26
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Re: Duct opinions wanted


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Have you tried google locator map and homestars, if u have it.

Lots of contractors there - i would keep looking a little more before giving up.
I do not see anything on the web for Google locator map?

Is there a service I can pay to design the system?
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Old 01-19-2018, 06:48 AM   #27
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Re: Duct opinions wanted


FBN back again. Suggestion . Within a 5 or 10 mile area of your property. Go on line and find HVAC Contractor's that have a 5 star reviews on Yelp and other review addresses. Look at all the reviews and weed out the wacko's ( there are many) and use common sense. Call 3 or 4 and get information from each one. Don't always go by price. Also ask if you can have names of satisfied customers' . Give them a friendly call and ask their opinion maybe even look at some of the installed systems. If you do your homework I am sure you can pick 1 or 2 your happy with.

OH, Make sure they are licensed in Florida and insured. Make sure this is the most important part.

Sorry if I am blunt like Trump .
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Old 01-19-2018, 07:39 AM   #28
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Re: Duct opinions wanted


28 posts in a day.... Dear lord!

I also sorta remember the old threads about this.

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Originally Posted by jjrbus View Post
Thanks, it is hard for the people up north and in Canada to grasp the no metal duct.
Many, but not all of us. We use metal in houses, and flex in commercial. Then again we sit on our heads, and drive backwards.... Or was that a dream, lol. Things are done differently in different parts of the world.

Anyways, 93*f seems a little low to use as a design temp for Florida. I'm not familiar with that area, and all that I remember the freezing temps when I visited a decade ago. That calculator usually undersized coming cooling a bit if you get sloppy, so make sure that you get all the numbers accurate. R6 is probably a bit optimistic for the ductwork. I'd use r4 in the calc. You'll get better at first but it diminishes with wear and tear.

I'll eventually find time to better respond to this thread...

PS. Lol FBN hvac.....

Cheers!
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Old 01-19-2018, 09:53 AM   #29
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Re: Duct opinions wanted


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Originally Posted by COLDIRON View Post
FBN back again. Suggestion . Within a 5 or 10 mile area of your property. Go on line and find HVAC Contractor's that have a 5 star reviews on Yelp and other review addresses. Look at all the reviews and weed out the wacko's ( there are many) and use common sense. Call 3 or 4 and get information from each one. Don't always go by price. Also ask if you can have names of satisfied customers' . Give them a friendly call and ask their opinion maybe even look at some of the installed systems. If you do your homework I am sure you can pick 1 or 2 your happy with.

OH, Make sure they are licensed in Florida and insured. Make sure this is the most important part.

Sorry if I am blunt like Trump .
I appreciate blunt, I don't want people being politically correct when I am doing something stupid!
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Old 01-19-2018, 11:01 AM   #30
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Re: Duct opinions wanted


You may have better luck with firms that engineer/design systems and have some good sub contractors to do the work than a typical guy who just does change outs and repairs.
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