Can I use vent line in attic?

[CountryBumkin]

Thanks all for this great forum.

I am remodeling my shower into a steam shower. I was planning to put the steam generator in the attic above the shower location (I have a one story ranch in Oralndo FL). It never gets below freezing in the attic and it would (might) make plumbing the steam generator easier.

If I put the generator in the attic, I am thinking I could put the drain line (pressure blow-off valve and backflush line) directly into the vent line (1-1/2" or 2" I think) which passes by right next to the potential gererator mounting location. Is there any reason why I couldn't cut the vent (it's PVC) and install a Y fitting then route the generator lines into the Y? I'll use the appropriate fitting so the line is threaded into the Y and no sewer gases get into my attic.

This seems like a great solution unless you guys have a reason for me not to.

The atternative is that mount the generator at floor level (possibly in a cabinet) then break the slab and connect the drain/backflush into a new p-trap connected to my existing shower drain line via a Y fitting.

Thanks.
Mike

[seaofnames]

I'd call a pro that is familiar with this type of installation and ask him/her.

You may want a copper/steel vent at this point to handle the temperature of the unit.

I dont see a problem with having an 'emergency' drain going down the vent of the one plumbing stack for your rancher, but then again your local code could say different.

[CountryBumkin]

Thanks for the quick reply.

You mention concerns over the temp of water that might go into the vent. Is the vent any different from the PVC pipng in the slab? If I don't use the vent line I have to plumb it into the drain line. It's the same material right?.

I don't have an expert to ask. Between you and me, I'm not pulling a permit. The county has enough of my money and their raising my taxes too. I'll post on the Garden Forum and John B Tile Forum, and I can call the Steam Generator manufacturer. That's abou it for experts.

I know the possiblity of leak would be a bigger problem if it is in my attic. I think I can install a pan (like used for hot water tank but with a drain fitting on the side) under the steam generator with a high water level alarm. So if the steam generator ever leaked, the alarm would sound and the water would go down the vent line - why I make my way up to the attic to shut of the supply.

[seaofnames]

I'd only be concerned about the temperatrue for the first foot or so coming out of the steam generator since it is so hot. Just make sure the pipe you have can handle the temperature. Most PVC/CPVC can handle that, but its always nice to have it over done a bit.

By the time its a foot or so out of the unit, it will/should have cooled down to a decent temperature.

[FloridaOrange]

From the Florida Plumbing Code.

803.1 Wastewater temperature. Steam pipes shall not connect to any part of a drainage or plumbing system and water above 140°F (60°C) shall not be discharged into any part of a drainage system. Such pipes shall discharge into an indirect waste receptor connected to the drainage system

I've done fitness centers with steam generators, to do it right the discharge needs to exit the building or into a waste receptor. This gives the water time to cool. Also, your PVC for your drain system isn't rated for hot water, CPVC I think is rated to 200*. Directly connecting that equipment, even if it has a basin or sump to let the water cool isn't allowed either.

[jadnashua]

A vent line that gets used as a drain is no longer a vent! Now, you'd probably never have enough volume from that steam generator to block it off so it couldn't work as a vent, but it's not right. keep in mind that when it gets time to sell, you might be in for some very expensive surprises after the home inspection. Also, all it takes is one disgruntled neighbor to turn you in to ruin your day, too.

[CountryBumkin]

Thanks again for helping me on this.

The hot water discharge into the PVC vent line would only occur if the pressure relief valve opened (i.e. emergency situation). While possible, this would be a very rare or a non-occurance (my hot water tank relief never opened). The auto-backflush valve does not discharge hot water according to the manual.
I suppose the pressure relief line could be run to the outside wall of my house. But it would exit just under the sofit and that wouldn't be good for anyone outside. I think I would rather take a chance on melting the PVC line in the attic.

You make a good point about resale. Just because I'm not pulling a permit doesn't mean I don't want this done right. I'm mainly not getting a permit because I'm concerned that if I pull a permit I will have a hard time with the inspector since I'm using Kerdi and our code (I'm told) doesn't allow/cover Kerdi installations. I don't need the hasel.

I think my only other option is to mount the generator at slab level and tie it into the existing shower drain line. I have to break the concrete anyway to install a Kerdi drain. The issue regarding high temp water discharging into a PVC line still remains - but this would only occur if the relief valve opens. And that is not supposed to happen.

If I install a Y into the shower drain line about 2 feet from the existing P-trap, would I be better off? I would then need a second P-trap for the steam generator line which will be about 3/4 or 1" diameter. Is this a better way to do it?

Is the 803.1 code referring to a steam (heat) pipe discharge or a residental steam generator for a shower. A steam generator is only supposed to discharge cool water during the normal backflush operation -but they still want the pressure relief connected to a drain (according to the manual).

[FloridaOrange]

The pressurej relief is similar to that of a water heater. It should be taken to an indirect drain or where allowed to the outside.
What's wrong with taking the line outside?

I seem to remember from my projects the shower steamers also have a purge, does your unit?

[CountryBumkin]

Steam unit does have an "optional automatic" purge. Manual says, with the auto-backflush valve installed, after a programmed cool down period the unit will backflush any sediment. I was going to buy the autoflush and let the backflush go down the vent line in my attic. It is a 1/2" line. Also the installation manual just shows the pressure relief valve dumping into the drain pan located under the generator then the drain pan gravity flows to an existing drain. I wanted to run the pan drain line and backflush line to the vent stack rather than tie into a drain under my slab.

I suppose there is nothing wrong with discharging the pressure relief outside the house, except that if I mount the unit in my attic, the discharge would be around soffit height and if someone was outside the house and the relief valve opened they might get hit in the head with the hot water. Therefore I thought I would just let the discharge go down the vent stack. Of course I could install a 90 at the soffit and run the line down to the ground too.

[Winslow]

If you tie the steamer drain into a vent then you want to tie into a vertical section of pipe (that ideally doesn't have any horizontal legs before it ties int the drain it serves.

Temperature isn't usually a problem as the unit usually waits 30 minutes before draining to allow the water to cool. The only time temperature would be an issue is if the T&P valve tripped.

[johnjh2o1]

I'm don't like any of this. Making a direct connection between water and waste.
If conditions are right sewer gas could enter the steam unit. It should be tied in with a indirect waste. Am I wrong in this thinking?

John