Most Efficient Water Heater?
I will install radiant heat and I also need to heat domestic water. One installer recommended the Polaris Water Heater ( http://www.americanwaterheaternews.com/new_products/polaris.htm ) and he said that was probably the best/most efficient in the market. Is he correct? Any opinion about that? Any suggestion to heat the radiant floor and the domestic hot water? I…
I will install radiant heat and I also need to heat domestic water. One installer recommended the Polaris Water Heater ( http://www.americanwaterheaternews.com/new_products/polaris.htm ) and he said that was probably the best/most efficient in the market. Is he correct? Any opinion about that? Any suggestion to heat the radiant floor and the domestic hot water? I am very concern with the efficiency and I would prefer to have one heating source, not two, for economical reasons and maintenance.
wow 96%! at 15 buck per month, no brainier, 10 years you save 1500 but you can give that to the contractor and plumber. another 5 years and poof, new one is needed. go tank less! way to go
I called the DOE about a tax credit for replacing a hot water heater. I was told there are NO residential storage tank water heaters that can qualify for the tax credit because none can meet the Energy Factor requirement of .82. However, there are some commercial storage tank water heaters that can qualify for the tax credit because they have a thermal efficiency of greater than 90%. But they said these models are larger than what is typically considered a residential unit and may not have the standard safety features of residential models. They said it might be possible to find a tankless gas system that would qualify for 30% of the cost, up to $1500.
They said both electric storage tank and tankless water heaters can not earn the ENERGY STAR because they have limited energy savings potential. The most efficient electric storage tank water heaters on the market have an Energy Factor of 0.95, “which represents 4.8% savings over the minimum federal standard (Energy Factor = 0.904). Electric tankless water heaters fare only slightly better. The best performing electric tankless water heaters have an Energy Factors of 0.99, which represents a savings of 8.7% in comparison to the Federal Standard (Energy Factor = 0.904).”
If anyone has found they did, in fact, get a tax credit for replacing a tank hot water heater – let me know.
The Polaris can not legally be used in NYC to make heat and domestic hot water.
Have you thought about solar thermal coupled with a mod/con boiler? Feel free to shoot me an e-mail if you would like to discuss the advantages/diadvantes.
heat@moltenmechanical.com
Any recommendations for those of us with forced air heat who will be looking to replace gas tank hot water heaters?
I’ve used the Weil McClain Ultra, it has a built in outdoor temperature reset which helps the efficiency, it also modulates to 20% of it’s rating. I’ve heard good thing about the Triangle Tube boiler as well.
If I had a working hot water heater I’d probably keep it if it’s not too old. Just install your new boiler with fittings for a future indirect tank.
Mod/cons are good if done right, especially with low temperature radiant heat, but expensive and complex. There is nothing wrong with good, much cheaper conventional boiler
I would just do the indirect system: http://www.radiantec.com/systems-sources/indirect-system.php
Never mixing the domestic hot water and the heating water.
I already have an old water tank (free) and I am not sure on the efficiency, but must be quite unefficient because it was purchased by the previous owner. Maybe it’s not worth to change it if it works well… What do you think?
Also, edifice rex, could you explain a little more on the mod/con boiler you are talking about? I googled it and I couldn’t really see with certainty what are you talking about. Excuse my ignorance.
I have no direct experience with these, but if he is proposing and open system [no separation of domestic and heating water] as is often done with these, do not do it.
http://www.radiantec.com/systems-sources/systems.php
Personally i think a mod/con boiler with an indirect tank is a much better combination.It will give you more flexibility and make outdoor reset much easier, some smart boilers have tis built in. And by the time you add the cost of a heat exchanger I don’t think you will save that much.
For long term savings design your radiant system for the lowest possible water temperature. If you have to use very hot water for heating, the condensing boiler loses much of it’s advantage.
You will note that the specs say 96% THERMAL efficiency (as opposed to 80-85% for a normal w/h). However, there are still tank losses., supposedly 1% compared to 20% (hard to believe)
Ok even if that: 95% vs 60%. You’re saving about $15/month. The Polaris is $2500 vs $600. Installing needs special venting. May require new gas line. Requires electrical line (oh, there’s additional electric usage, not usually factored into the efficiency). If you don’t have all of those, add $1000. Your ROI is now 18 years. Maybe there’s a difference in tax credits.
That said, if I had the money all those who install Jackal ranges and Neg-Zero fridges, I would because in a small way it is “greener” than a regular w/h. And of course, compared to a boiler and separate w/h it’s better.