Tankless water heaters?

[Eug]

Tankless is so your aged parent can wash her hands with warm water after peeing in the middle of the night without having to wait for the hot water to get there. She has a small unit under her bathroom sink.
Since a tankless unit isn't keeping a tank full of water hot 24/7 why doesn't it save energy?

1. You're talking local on-demand tankless. Most people in North America get whole-house tankless, as a replacement for a tank.

2. Tankless will save energy, but it won't save money in most cases, because of the higher up front costs and because of the somewhat increased maintenance costs (unless you do all the maintenance yourself).

3. Part of the energy savings may also be lost by increased hot water usage. One study in the US suggested that homes that switched from tanks to tankless did on average use a bit more hot water.

 

[Humpy]

Our definitions of a boiler must be quite different, but NM.

That or I really don't need a boiler in Florida.

Probably both.

The boiler in my house is the size of a large microwave oven and serves the hydronic heating system and also provides all the hot water we can use. It is efficient but uses dead simple technology that can be maintained by an idiot (me).

Where I live our heating and cooling is often provided by separate systems. I imagine that in FL, if there is a heating system, it is just part of the air conditioning.

 

[NetWareHead]

I was being fictious actually, why would you want a boiler in a house ?

Those houses that have hot water baseboard heat or radiators have a boiler. If you have a high efficiency condensing boiler and tie an indirect water heater off a boiler zone, you now heat water at the efficiency the boiler operates rather than a water heater's efficiency rating. Plus it keep the boiler operating regularly even thoughout the summer for domestic hot water purposes even if there is no home heating need. In many cases its not a good thing to let a boiler sit idle.

 

[who?]

I think tankless was invented for ancient housing in europe that was built before water heaters were invented.

 

[rh71]

nvm

 

[Red Squirrel]

I've been sorta considerating it, if ever I need to replace my current water heater. I have a gas tank one and those arn't very efficient due to all the heat that gets wasted going up the stack, and fact that they draw cold air in the house. I'd probably go with a dual pipe (intake + exhaust) gas or maybe even an electric, since I'd be able to just install it myself. Gas, I'd have to get a licensed pipe fitter to do it (don't have the tools to work black pipe and rather leave gas to pros anyway).

I don't know how well it works in the north though. The incoming water is about 0 degrees here. Just to say it's a tad over freezing.

 

[fstime]

Probably both.

The boiler in my house is the size of a large microwave oven and serves the hydronic heating system and also provides all the hot water we can use. It is efficient but uses dead simple technology that can be maintained by an idiot (me).

Where I live our heating and cooling is often provided by separate systems. I imagine that in FL, if there is a heating system, it is just part of the air conditioning.

Yep, 96% efficiency Triangle Tube Prestige which can modulate down to 25% output, is the size of a microwave, and vents directly outside via PVC pipe. Inside construction is extremely simple with little to no unnecessary complexity.

Radiant heat is so much more comfortable than forced air, it is not even comparable.

 

[Eug]

I've been sorta considerating it, if ever I need to replace my current water heater. I have a gas tank one and those arn't very efficient due to all the heat that gets wasted going up the stack, and fact that they draw cold air in the house. I'd probably go with a dual pipe (intake + exhaust) gas or maybe even an electric, since I'd be able to just install it myself. Gas, I'd have to get a licensed pipe fitter to do it (don't have the tools to work black pipe and rather leave gas to pros anyway).

I don't know how well it works in the north though. The incoming water is about 0 degrees here. Just to say it's a tad over freezing.

Don't you live in Ontario? If so, you'd be nuts to go with an electric water heater over natural gas. The cost to run the thing would be very high.

Electric water heater tanks make sense in places like Quebec (where Hydro is cheap) or if you have no access to natural gas, but otherwise they are not recommended due to operating cost.

 

[Red Squirrel]

Yep, 96% efficiency Triangle Tube Prestige which can modulate down to 25% output, is the size of a microwave, and vents directly outside via PVC pipe. Inside construction is extremely simple with little to no unnecessary complexity.

Radiant heat is so much more comfortable than forced air, it is not even comparable.

Yeah if I built a house I'd probably go with a boiler system and radiant heat. In floor heat and maybe even old style rads, those were the best. I'd still have forced air though as it's still nice to be able to circulate air, and I'd have AC on it too, and for the really cold winter days you'd still want the furnace running too.