How much do insulated toilet tanks really reduce condensation?

[peggyk5]

I have a summer cottage in the Adirondack Mts in upstate NY which has a big problem with toilets dripping condensation onto the floors. We have well water which is of course very cold, and the current toilets are probably 30 years old. I am about to replace all of the toilets and have read that the new toilets, which use less water and might not completely empty the tank on every flush, are less likely to sweat. So my question is whether insulated tanks will make much difference, especially during the times when we have lots of people staying in the cottage.

[jimbo]

On your very old toilet which probably flushes 5+ gallons every time....condensation will be a big problem. New toilets which flush as little as 1/28 gallons, that of course will be LESS of a problem, unless of course you have to flush 3 times!

You can get foam liner kits to put inside your old tank. That will help. And the old tried and true solution is to install a mixer and fill the tank with lukewarm water.

[Gary Swart]

New toilets use only about 1/2 of the water in the tank per flush. The water remaining in the tank is already tempered to room temperature. This means that the incoming cold water will mix with this tempered water and this eliminates or at least reduces the condensation. Also, this "new" water has been sitting in the pipe for awhile and is not going to be as cold as it was coming from the well. Repeated flushes will bring more cold water of course, be that normally is not going to be a frequent happening.

[jadnashua]

Insulation probably will not stop condensation on a toilet that is used and flushed frequently with very cold water. Since insulation only slows heat transfer, but doesn't stop it, eventually the tank can become cold enough to sweat. So, even with the existing toilet, if you want to stop it, install a tempering (mixing) valve to raise the incoming water above the dew point. Lots of water may not cost you much directly, but it does cost more because the pump runs longer and you stress the septic field more if you don't have a sewer line. So a new, low-flow toilet has advantages, regardless. That might be enough...just depends on the actual frequency of flushes and your incoming water temp, and the current dew point's interactions.

[LLigetfa]

I have solved the problem of sweating due to heavy use by deploying the mixing valve as Jim mentioned.

[Runs with bison]

Installing a lower volume per flush toilet will relieve much of the hydraulic load on the septic system. I recall a friend's lake home that had issues with this during parties every year...put a few dozen engineers together with a lot of BBQ and beer and the septic is soon at capacity...and then some. Wasn't long before the yard got soggy. Did I mention that the majority of the city's drinking water came from this reservoir and was winning the top national taste award year after year?

[peggyk5]

Thanks, everyone (except maybe Runs with Bison for that water analysis!). I'm concluding from this and other threads that the insulated toilets only provide marginal improvement. Since we often have 10 or more people staying in this cottage I doubt we can avoid the sweating without mixing so I'll try standard new toilets and see if there's any improvement. If not, we'll mix in some hot.

[Terry]

I do sell a few TOTO Drake toilets with the insulated tanks.
ST743SD is the tank number.
The D is for the insulated model. I sell them mainly in Alaska.

[LLigetfa]

Even if you go with an insulated tank, the bowl may still sweat under heavy use. In this neck of the woods, the guys mostly just go behind a tree. You might consider an outhouse if they are not outlawed.