Air Handler drian pan when hung horizontal

[bradley wayne]

I just started a new job as a technican/installer for my first company and Im going to fire off some questions that I have written down after my first week. To imbarassed to ask my boss and hes to busy. But I need some expert advice.
I hung a new air handler on a ceiling in a guys garage last week and I noticed the drain pan for the unit we were replacing was only under the evaporator? With it being horizontal I felt like a pan should have been under the entire unit? what do you think? also, a tech working with me had me plug the overflow condensate drain, he said if it got a leak it would run out the unit and trip the float switch I had put in. What is best procedure on this type of set up.

Thanks,

[Sammer VII]

lol, I wonder how many residential AHU produce water...

[energy star]

The pan should be under the whole unit (If its an Air Handler) I will say that if it is a slab type coil it could just go under the coil. I just use the primary drain on the air handlers.

Congrats on the new job.

[bradley wayne]

Thank you

[lentz]

Pan under the entire unit.(Heat Pump) Put something between the unit and the pain. Maybe a little slope toward the drain opening so very little condensate will stay in the unit. We Plug the overflow also. No air in or out.

[ga-hvac-tech]

Agree with full pan, plug (important), and slope... I would put a safety on the drain pan also... Some folks break the red wire, some folks break the yellow... each way has it's advantages.

[bmathews]

lol, I wonder how many residential AHU produce water...

If you hook up a condensing unit to them. They all do. I'm not sure if the OP is using the correct terminology. An air handler generically refers to a piece of equipment with an evaporator coil, blower and heat strips all in one. A furnace is a blower and controls for gas heating and the evaporator coil is a separately purchased component which are then connected together in the field. If this is what you have, then most of the time a secondary drain pan will be installed just under the evaporator coil. Best practice is to install it from plenum end to plenum end. Water has a way of finding its way to about an inch outside the drain pans span and dropping. If you have an air handler as I described above, then you want a drain pan at least under the physical unit itself. Not just half of it.

[bradley wayne]

It is a gas furnace with an evap. coil attached to it. It mounted to the celing in his garage. The orginal unit only had a pan under the evap. I felt like one needed to be under the entire unit but we went with just under the evap.
The home owner actually told me to take the pan off, said it was ugly. I refused to do it. I wire dthe float switch through the yellow wire.


Thanks for the input.

[crab]

if its a 90% furnace then the whole thing needs a pan... if 80% not...diff is 90 is vented with PVC 80 % with metal..as a service tech i like to take the over flow and plumb into the safety pan...have seen a few cases where water ran the duct work when primary plugged up.
hope this helps
CRab

[bradley wayne]

Crab,
I thought about plumbing down into the pan, but I was afraid it was allow access for wasp, flies, bugs ect to get in?

[crab]

i usually use a ptrap for it too..but anythings possible..i've seen slugs get in them outside also but not likely. so is it a 80% or 90%

[ga-hvac-tech]

It is a gas furnace with an evap. coil attached to it. It mounted to the celing in his garage. The orginal unit only had a pan under the evap. I felt like one needed to be under the entire unit but we went with just under the evap.
The home owner actually told me to take the pan off, said it was ugly. I refused to do it. I wire dthe float switch through the yellow wire.


Thanks for the input.

If the customer does not want a pan (which is probably against code), I would have them sign a ticket that they are responsible WHEN it leaks.