Mini split in a condo...best way to deal with condensate?

[DaleGribble]

Hi all,

After a heat wave from hell and going back and forth with my condo, I finally got approved to install a mini split in my condo. But after talking to many contractors and an engineer (my compromise was getting an engineer to help quell the condo board's concerns RE: envelope penetration for the linesets, and also for drainage), I have learned draining isn't as straightforward as I thought.

Condo board's concern is they don't want the condensate dripping on the patio constantly which they think will leak below. Ironically, it rains a ton here (about 192 days per year), but that's neither here nor there. So I have to find a way to rid the condensate when both in heating, and cooling mode.

Cooling mode, most contractors who gave me estimates want to do gravity drain outside. Some have said to tie in the condensate line to my patio floor drain. My engineer seems apprehensive to sign off on that as he thinks the condensate's acidity could pose a problem with the patio membrane. I have heard very conflicting information about this, whether it's just water or whether it is acidic. Patio is stone tiles with gaps and a floor drain. I thought that the floor drain would go directly down to the storm drain, but there are these metal pipes protruding from the sides of the balcony, which make me believe it may drain outwards?

If not, what are those horizontal pipes jutting out from the balcony for?

This is what my storm drain looks like

That's on the patio. Some contractors want to tie the condensate gravity drain into that, but the concern is the condensate dripping where it shouldn't. I mean, rain does get on there but not at the same rate as condensate.

The other option is to tie a drain line to the side of the gutter, and drain it directly into the gutter

Or, run condensate pumps and tie it into the laundry line. That would require pumps with surface mounted drain lines running about 30 feet through my condo. Aesthetically won't look amazing. My big concern is leaking on my walls if the pump dies which I do hear they do.

Final option would be to just have a removeable bucket on the patio and drain the condensate into that, and just empty that daily. The most archaic but I just want AC this summer.

I'm in Western Canada and this last heat wave brought temps well over 100 degrees inside for several days and even on the "cooler" days it was well over 90 inside in the evenings with my portable AC unit blowing full. I face west and my condo is a loft with huge windows and huge 22+ foot ceilings.

Thank you all for your input.

 

[Fitter30]

Condensate from a heat pump isn't acidic either from the inside unit or from the condensing unit going into defrost mode. Might need a drain from the condensing unit for defrost mode ask your contractor. Condensate from a gas fire burner from a hi efficiency boiler or furnace is acidic from the property of combustion. Pour a bucket of water down the patio drain see if the comes.out the pipe ( bet it will). Condensate pumps should have a overflow switch if they die shuts off unit.

 

[Sponsor]

 

[Jeff H Young]

Roof scuppers, for overflow might have a separate one that runs down to ground or to storm drain.
Often there is a drain and a overflow

 

[wwhitney]

So A/C condensate is non-acidic, but it's effectively distilled water, I believe. That can be aggressive in a different way; is it a problem for metal piping?

Cheers, Wayne

 

[Jeff H Young]

How about rain water does it catch a bunch of minerals falling from sky or is it similar to distilled water? I wouldn't expect harm

 

[Jadnashua]

Rain water can easily become acidic, but condensate from a a/c system isn't. It should be able to be dumped anywhere you can safely put it without worrying about acidity. A drain would seem to be a good place.

Inside, during cooling, you'll have condensate from the cooling coils. In the winter, the outside coils may see some ice accumulation, and will periodically go through a defrost cycle...managing that can be tougher as it can refreeze, depending on where it gets directed and the ambient temperature. Neither is acidic, though. During a cold snap, the condensate on the outdoor unit might freeze up in the drain. The humidity levels in BC can be pretty high.

 

[DaleGribble]

Thank you for the replies. I am pouring water down the drain and don't see it coming out the pipe. How can I tell if it's an overflow or the direct drain? It does rain a ton here but rain is of course at a much slower flow than condensate.

 

[Jeff H Young]

An over flow typically sits higher off the deck then a drain and its common to have both a drain and a over flow

 

[DaleGribble]

Working with an engineer on this one to appease my condo board. My engineer did not think the condensate would be safe to put in the gutter (said it would prematurely wear the metal on the gutter) and said it would be pulling things from the air that should not go down a rainwater drain. He suggested it go into a bucket/container as the safest way to catch condensate and pour down sink or bath tub. Apparently if pumps fail it can invite all sorts of leaking problems within the house.

My contractor disagrees with a lot of these points.

So now I am at a loss as to who's right or what to do.

 

[wwhitney]

My engineer did not think the condensate would be safe to put in the gutter (said it would prematurely wear the metal on the gutter)

Ask him what metals fresh atmospheric condensate has been documented to corrode (presumably not any of the metals used for the fins of the heat exchanger or drain pan on the HVAC units), and then find out what metal the gutter is made of.

and said it would be pulling things from the air that should not go down a rainwater drain.

Ask him what the fresh atmospheric condensate is going to be pull from the air that is different from what rain pulls from the air.

Make sure he understand the difference between A/C condensate and combustion condensate from a gas appliance.

Cheers, Wayne

 

[DaleGribble]

Ask him what metals fresh atmospheric condensate has been documented to corrode (presumably not any of the metals used for the fins of the heat exchanger or drain pan on the HVAC units), and then find out what metal the gutter is made of.


Ask him what the fresh atmospheric condensate is going to be pull from the air that is different from what rain pulls from the air.

Make sure he understand the difference between A/C condensate and combustion condensate from a gas appliance.

Cheers, Wayne

He told me that the fins from the compressor can be corroded (without regular service) from what it draws in the air. Apparently whatever it is isn't supposed to go down a rainwater pipe but would be fine for soil, or wastewater lines.

I'm not well versed in this stuff, hence my having to get a pro opinion. I did ensure there was no confusion about the fact that we were speaking about mini splits and not gas fired furnaces.

All I want is some A/C for the summer.

If the course of action is to get a removable 5 Gallon Home Depot bucket to drain the condensate, so be it (one contractor told me a lot of people without drain access do this), though one contractor only wants to do condensate pumps drained inside and seemed put off by any sort of change to their designs or scope of work.

 

[Jadnashua]

Household cleaning chemicals, especially liquid bleach, can shorten the life of things, as the chlorine can be an issue. Usually, that's not an issue. It's more of an issue if it's caught in the inlet air to a combustion device, as the heat combined with the condensate is what converts things to acids...the condensate from an a/c unit, other than dust, pollen, and microbes that might be in the air that gets sucked by, is close to distilled water. The condensate from a combustion device, unless you were burning pure hydrogen (we might get to that in 20-years), is acidic, often in the ph range of -4.5 or so. That should be run through a neutralizer before it is dumped anywhere. The ph of an a/c unit should be very close to neutral, and better than acid rain.