Navien Tankless thread ... I just had one installed last Friday. http://www.navienamerica.com/product...skin=ts_heater
The time is coming...but is it here yet.
Are there any tankless water heaters efficient enough to run PVC for their intake and exhaust vents?
Last edited by Terry; 11-08-2010 at 11:08 AM.
After looking for days, it turns out I've been overlooking many PVC vented condensing units from most top brands. Most have at least one model, near the top of their line up.
I happen to like the Rinnai R98LSi, a brand I looked at once before when looking into tankless water heaters. Now I'm pretty well set on the tankless for many reasons other than endless hot water.
This is my #2 option: Rheem RTGH-95DV
Last edited by Terry; 04-20-2011 at 11:01 PM.
IIRC Rheem used to be re-badged Palomas, but may have switched recently (to Takagi?).
If you have any distance to go with the exhaust venting, you may be better off going with a condensing version. The unit may cost considerably more, but PVC venting is far cheaper than stainless, and A: the installed cost may be lower and B: the avaibable tax & rebate subsidies may be higher.
Unless you take your incoming water directly at the outflow of a glacier, or are running a monster of a shower with deluge-sidesprays a 199K burner is likely going to be overkill. Sure you really need it? What are your incoming temps and flow rates like?
If you heat your house with a hydronic boiler(force hot water baseboards/radiators/radiant floor) you may get as-good or better efficiency, and noticably BETTER flow performance with an indirect-fired tank running off the boiler than with an 0.84 EF tankless, for a lower installed price (also subsidized.)
I am only looking at buying condensing units...which vent via PVC. I started this thread asking which units vent via PVC and learned that there are options out there, but at this time they are the top of the line models only. Big $$$$. The Rinnai 98Lsi is what I am narrowed to right now, it requires 4" PVC.
Yes, it is overkill in my opinion also. But our state has some weird codes on tankless right now, and some people I've spoken to claim that the majority of tankless heaters wont meet code in my 2 bath, 2 1/2 bath home. The 98Lsi can clearly run 2 showers at a very high temp rise and flow rate.
But I'm not concerned about hot water supply/demand...actually. I simply want closed combustion via PVC venting like a furnace. None of the crap that falls in the middle.
Tank, tankless, Hybrid and all other heater options aside...closed combustion water heat is the future.