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Chad711
11-09-2005, 06:59 PM
Has ANYONE seen a system that had the coil on the return side, actually work. 2 of the guys at the shop are trying to make this work, no space on supply. Went out there tonight and the new trane x14 is tripping on hp. TXV fed, I told them it isnt going to work, pull er out and figure a way to redo the supply.
millerman
11-09-2005, 07:10 PM
Uhhh..? Heat pump indoor coil always goes on the return side, maybe I'm confused....
trey r
11-09-2005, 07:13 PM
you said this is a heat pump? on trane airhandlers the coil is on the return end. am i reading this right?
Chad711
11-09-2005, 07:17 PM
You guys been drinkin?
Mr Bill
11-09-2005, 07:18 PM
Originally posted by Chad711
Has ANYONE seen a system that had the coil on the return side, actually work. 2 of the guys at the shop are trying to make this work, no space on supply. Went out there tonight and the new trane x14 is tripping on hp. TXV fed, I told them it isnt going to work, pull er out and figure a way to redo the supply.

Furnace or Air Handler??
trey r
11-09-2005, 07:18 PM
yea but that is beside the point.
Chad711
11-09-2005, 07:18 PM
Furnace is a Lennox Pulse.
trey r
11-09-2005, 07:19 PM
IS THIS A DUEL FUEL SETUP?
Mr Bill
11-09-2005, 07:20 PM
Originally posted by Chad711
Furnace is a Lennox Pulse.

Yes it does make a difference you don't put a coil on the return of a gas furnace in Texas.
Chad711
11-09-2005, 07:23 PM
Originally posted by trey r
IS THIS A DUEL FUEL SETUP?

yes
Chad711
11-09-2005, 07:24 PM
Originally posted by mrbillpro

Originally posted by Chad711
Furnace is a Lennox Pulse.

Yes it does make a difference you don't put a coil on the return of a gas furnace in Texas.


I agree, you shouldt in any state...
trey r
11-09-2005, 07:24 PM
NOPE NOT IN NORTH CAROLINA EITHER.
Swampfox
11-09-2005, 07:25 PM
If the airflow is there it wouldnt matter to the heat pump what side of the furnace the coil is on.
millerman
11-09-2005, 07:26 PM
Originally posted by Chad711
You guys been drinkin?



Unfortunately no. What coil? What application? I think you need to set the wild turkey down and re-read your post. Hic :eek:

All fossile fuel furnaces the coil must be on the supply.
Mr Bill
11-09-2005, 07:27 PM
Originally posted by swampfox
If the airflow is there it wouldnt matter to the heat pump what side of the furnace the coil is on.

I guess if the coil gets a bad leak and you don't mind smelling the phosphate gas go for it.
Swampfox
11-09-2005, 07:30 PM
I didnt say it was a good idea to put it there, but if its tripping the HP switch, its not because the coil is mounted on the return side
Chad711
11-09-2005, 07:36 PM
Swampfox, I disagree. First off you are pulling the air through not pushing, also there is a higher static pressure going through the coil when placed in that direction, most important though, its going to DESTROY the furnace with all that humidity pushing through it come summer.
Swampfox
11-09-2005, 07:42 PM
I know about the heat exchanger issue, but in almost every air handler manufactured the coil is on the return side, why does it become an airflow problem in a gas furnace application?
Chad711
11-09-2005, 07:45 PM
Well I dont know the last time I saw an airhandler and nothing else around here so I cant say. Maybe the coil design on those is differant.
karsthuntr
11-09-2005, 07:48 PM
It is not an airflow problem due to where the coil is located.
Chad711
11-09-2005, 07:54 PM
I guess I could have looked into it more, maybe there is an issue with the HP. Pressure steadily rose over 500 until the HP opened...

I just have never seen one on the return, and have heard it will never work.
tinknocker service tech
11-09-2005, 08:09 PM
i totaly disagree with coil on the return side on any furnace for ovious reasons. but seeing this is a pulse with a cast iron and steel tube heat exchange rust should not be a real problem for a while although it will void the life time warrenti to the original homeowner or the 20 year also. either way this shouldnt matter to the coil there are other issues going on. the heat pump should still work fine. i have a coustomer with the same set up it has worked for 18 years this way and is doing fine. keep trying to get him to let me do it the right way but all he says is when it crapps out he will replace the intire system and then i can do it the way i want. so be it
davidr
11-09-2005, 08:19 PM
Did you take any static pressure readings to rule out the possibility of an airflow issue?
Chad711
11-09-2005, 08:23 PM
No I was in and out, just stopped by to drop off a grill for the guys installing it, I was on my way to another call. Im sure I will be there tomorrow looking into it more.
smokin68
11-09-2005, 08:36 PM
Most package HP's the coil is in the return, but has nothing to do with high HP. I agree with rotting out a HX on a dual fuel though..
Carnak
11-09-2005, 10:34 PM
heating is not the issue its the cooling. Cooling coil on gas furnace has to be a blow through coil
RoBoTeq
11-09-2005, 10:41 PM
Well, it doesn't have to be to work, just to keep from damaging the heat exchanger. This is why you don't get long warranties on heat exchangers of packaged gas units where the evap coil is before the heat exchanger.
millerman
11-10-2005, 09:23 AM
I am curious if any one ever reads install manuals or are they used primarily for knee pads? Electric air handlers or fan coils always have the coil mounted on the return, fuel burning equipment (residential furnaces) require the coil be mounted downstream of the furnace. If your popping of the high pressure switch and it is a heap pump, explore the reason for this. The location of the coil doesn't matter to the pressure switch unless the coil is after the furnace and both are running (furnace and heat pump). The only reason a coil is mounted after a fuel burning furnace is because of rust. What state is the system in when the HP switch opens? Heat pump running and no fire from furnace just blower? This seems to be simple diag procedure. Good luck
Chad711
11-10-2005, 08:23 PM
No the gas isnt running. Damn, anyways I didnt go back, was building a walkin all day, thankfully. Dont know if anyone went yet.
berg2666
11-10-2005, 09:38 PM
You did say the sytem was going out on High Pressure. Check the reversing valve for proper operation.
Chad711
11-10-2005, 10:35 PM
How would this make it go out on High Pressure? Its hotter than mollases after the txv.
jerry-in-grapevine-tx
11-10-2005, 11:11 PM
why would you want a heat pump if you had a gas furnace?
karsthuntr
11-11-2005, 07:46 PM
Originally posted by jerry-in-grapevine-tx
why would you want a heat pump if you had a gas furnace?

In some areas of the country electric is cheaper than gas at mild outside temp's.

Most of our winter averages 40deg's. The heat pump runs anytime it is above 35 deg's and below 35deg's, the gas furnace will run. This is called a dual fuel system.
Chad711
11-12-2005, 12:06 AM
Possibly had an undersized r/a, 8x14. We will see...
jacob perkins
11-12-2005, 12:31 AM
Originally posted by Chad711
Possibly had an undersized r/a, 8x14. We will see...




thats it .increase airflow