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New Cased Coil - Install to Furnace - PICTURES!!

45K views 39 replies 6 participants last post by  kennzz05 
#1 · (Edited)
Ok, I am learning everthing I do with this Furnace install the long way. A lot of reading and slowly figuring things out. I am stumped on this one. I picked up my cased coil today and read through the install instructions after dinner. I then lifted the coil up in the attic and put the flanged side of the coil away from my furnace outlet air.( Trane XR 90 downflow) so that both flat sides where together, the condensate drain was down and the apex of the coil (im assuming the pointed end) was away from the furnace. In order for this to be true the gas and liquid line which I call the front side of the coil was actually oposite the front side of the furnace. I started looking at how to attach the three furnace brackets included. The manual says " two brackets are used to attach the rear of the coil and furnace and one bracket is used to attach the front. The two rear brackets will use existing screws on the coil enclosure (two on each side at the bottom). Now since my front of the coil (pipes exiting) was facing towards the rear of the furnace the two bolts the manual was talking about was actually towards the front of the furnace and would not work in this position because the outlet of the furnace opening is offset towards the back of the furnace and the brackets have to go around both the furnace case and the coil case which is not possible in this position because of the offset. If I install the coil so that the brackets work as shown in the manual the condensate drain is on the top side of the coil. The manual says I have to change the baffle around for horizontal right configuration but since I have a condensing furnace it can only be place on the left side like I have installed mine. If anyone can make sense of this please help. Thanks. I provided the supply house with my furnace model number to order the correct coil. The coil I recieved says it can be used with both up and down, left and right horizontal so I don't see how I could have the wrong coil. The first few picture below are with the flange towards the furnace(not what the manual says to do). I was just trying all options. The forth pictures shows how the bracket won't work when I place the coil according to the manual. The fifth pictures shows where the bracket is suppose to be (backside of furnace so it can mount outside of the case which is not possible on the front because if one did the outlet of the furnace and coil would not line up obviously. The last pictures shows the apex of the coil away from the furnace, flat side towards the furnace, and condensate drain down. In this configuration the bolt to mount the brackets are incorrect as described above. Any ideas?

Here is a link to my coil manual: http://www.trane.com/CPS/uploads/userfiles/dxunitarysystems/split%20systems/coils/18-ah39d1-4_12162007.pdf

If you look on page 3. The furnace actually looks like it is on the right side because of the way the offset of the furnace outlet is shown.
 

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#2 ·
cant tell from the pics but if the coil and furnace are the same dimension or at least close like within 1 inch id ditch the brackets they gave you and just use pieces of s slip cut down and drill screwed into both furn and coil just use short screws and you should be good seal with 3 in metal tape
 
#5 · (Edited)
So just so I am understanding correctly. I should have the top of the A facing the outlet of the furnace(backwards from what the manual says for a left horizontal downflow) with the drain at the bottom and the gas and liquid line on the same side as the front of the furnace. For that arrangement the flange of the coil would have to fit inside the bottom of the furnace which is flat. This exact arrangement suggested by kennezz05 is shown in the first picture.
 
#6 · (Edited)
if trane says absolutly dont use the top of the a as entering side than thats ok too in a downflow application thats the way it would end up but if you want to turn it so bottom side of the a is entering side that is fine also i think the main reason is there is one way condensation is more likely to be blown off the coil fins (and yes by entering side i mean the outlet side of the furnace) if the flanges end up aiming at the furnace take a pair of tongs and flatten them. its done all the time and no big deal and use slip screwed to mount it (you understand what i mean there?)



if trane isnt specfic as to which way coil is turned id do it the way the first pic is and just flatten the flange out some companys carrier i think even perforate the flange to make it easier to bend
 
#7 ·
Trane does suggest using a guard when installing the (A) away from the furnace outlet. it is angled upward on the outlet side which would collect the water and drain it back into the bottom. I can bend the flange flat but I am not familiar with a slip and screwing it to the mount. Trane does specify which way to mount the (A) but the manual isn't printed right or something because there supplied mounts do not work right. Tran says to mount the (A) away on left horizontal applications.
 
#8 ·
Trane does suggest using a guard when installing the (A) away from the furnace outlet. it is angled upward on the outlet side which would collect the water and drain it back into the bottom. I can bend the flange flat but I am not familiar with a slip and screwing it to the mount. Trane does specify which way to mount the (A) but the manual isn't printed right or something because there supplied mounts do not work right. Tran says to mount the (A) away on left horizontal applications.

i would turn the coil whichever way you dont need the optional drain kit if it requires flattening the flange than do it as far as the slip thing slip is whats used to put sections of duct togeather 2 sides slip togeather and the other sides are attached with drive material anyways slip is basicly just a piece of sheetmetal bent in an s shape about 1 and1/4 inch wide it comes in 8 foot lengths but you only need about1 foot 4x 3 in pieces screw one side to bottom of coil than other side to side of furnace its quite strong as its 3 pieces of metal thick do you understand you just use them kinda like straps to join coil to furnace are the coil and furnace the same width
 
#9 · (Edited)
I assume that a s slip & drive is the same thing as a s cleat and drive cleat. Is there some sort of felt that I put between the coil and furnace to seal? I think I understand what to do. I won't actually be using the slip to connect it like you would two pieces of duct I am just using them for straps. Couldn't I do the same thing with a piece of 1/8 flat iron. This seems somewhat unprofessional. Do I wrap the joint with anything to cover the connection or hide the brackets? When I bend the flange do I bend it towards the center of the coil or towards the outside to flatten?
 
#14 ·
will you be useing supplyhouse premade duct? if so i think although its alot easier to work with you probably dont want to use the bubblewrap insulation use the tried and true fiberglass( any duct guys out there to confirm???) ok i think we have just about beaten this thread to death and glad to help nice talkin to ya if ya need anymore help i check email more than this kennzz05@yahoo.com
 
#15 ·
I will be installing a plenum on the outlet of the furnace then attaching two 10" round metal duct from local home improvement store to each side of the plenum. I will have the sheetmetal shop that is making my plenum put air vanes inside the plenum to help direct the air into each 10 in. line since it will essentially be a square box with two lines out each end forming a TEE.
 
#16 ·
crap thought we were done here :) ok dont know what size furnace is but make sure and you probably have that that is sufficient size duct to handle the airflow or youll have overheating issues you dont need turning vanes just put dampered takeoffs on the plenum and really id just make a square box as your plenum and tap outa that you dont need anything elaborate for what your describeing you can make it in two pieces the first being the 4 sides of the box with a 1/2 lip on both ends of the box so you can screw it to itself where the ends meet (so they overlap) and 1/2 lip at top and bottom top bent inward bottom bent outward so it can be screwed to the coil. than you just make a "cover" for the open end of the box with 1/2 lips on all 4 sides so it can be secured
 
#17 ·
It is making more sense now. I can make the plenum myself out of the flimsy metal available at Home depot in the HVAC section. I will cut four pieces to size and then make lips on the sides of two pieces that I can screw to the other two pieces to form the box. I will make a lip on the end to attach to the coil. i will do the same for the end cap.

I may just go ahead and use 12" round rigid duct instead to make sure it is big enough. I will have two trunklines out each side of the plenum so surely that is enough.
 
#18 ·
i was wondering when we would start a second page:laughing: you got it although if you have an re michaels nearby id go get the metal there or other a/c supply house but not knowing where u are i dont kno if you mentioned it or its on your sig. sorry
so how many btus is furnace and tonage of a/c you can figure 450 cfm per ton try googleing ductulator it will tell you how big ducts should be based on tonnage also furnace should mention airflow cfm somewhere
 
#19 ·
I am located in Southern California. A lot of supply houses won't sell to me because I am not a contractor. Is there a specific type of metal I need to get. Prefered guage? Furnace is 60,000 btu with 3 ton A/C. I will look into the ductualator. Surely two 12" metal ducts will be big enough. Can I be to big?
 
#20 ·
yea too big and your airflow will peter out how far are the runs if they are really long you need to progressively get smaller and smaller to maintain velocity and you could call supply house and ask if they will sell the metal to you not like you have to be licenced to buy a piece of metal thts like saying they wont sell you any air filters explain this is for your house and your not doing some hokey sidejob if you have to. i cant remember gauge its been a while but im thinking 18 gauge
 
#26 ·
well you seem to want to be mysterious about the gauge let me say frankly scarlett i dont give a rats patootie what gauge as i am now a over the road truck driver and dont do this work anymore (and im saying this all with a smile no hostility) but it might benifit the original poster but ill try one more time 28 ga.??? or 26 i keep wanting to put an 8 in there please end my suffering...ken:laughing:
 
#27 ·
28 or 26 gage would me fine. I would have the sheetmetal shop make the plenum for you. I will hold up better.

No way of knowing if the duct would be sized right until we have some model numbers of the equipment you are installing. Poor duct design will loose your units efficiency just for starters. It could also cause a multitude of problems with your whole system. A ductulator will only help so much. Watch your pressure drop with every fitting.
 
#32 ·
Ok, look, I'm not trying to bust your efforts, but those cinder blocs are going to transmit noise and probably wear a hole in your drain pan.

The sheet metal has to be 26 gauge minimum. You should have that furnace SUSPENDED from the roof with threaded rod connected a length of squared metal stock. If you really want a quiet install add another piece of square metal stock and have it sitting on thick springs.
 
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