Most efficient way to heat hot water in our situation?

featherz

Due to a pile o' stuff happening at once, we had to do many high dollar projects and had to skimp on the furnace install (furnace, septic, well, sick cat, etc - all needed repair/replacement this year). We ended up with another tankless coil system (oil) which is working fine and appears to run less and use less oil than our almost 40 year old leaky vaillant.

It's coming up on winter and it's Upstate NY, so it will be on most of the day for both heat and hot water no matter what. The plumber suggested we add (DIY) an electric hot water heater for the summer, enabling us to shut the boiler off. I've seen others suggest this will cause rust or other issues with the boiler - and we do have a rather damp basement. Any truth to this?

Another suggestion I saw was to keep it as the source of hot water, but shut it off if you won't be home using it for long stretches. We'd probably be able to shut it off completely from 8AM to the next morning around 4AM during the week - would starting it up each morning cause any problems?

Adding an indirect oil tank is probably not an option at this time - just curious if anyone had any thoughts/suggestions.

H.

Bob Bona_4

Yes, shutting it down would not be good for it. Takes a toll on gasketed areas and creates a damp, acidic, sticky, tarry residue inside the unit.

In your situation, the cheapest option is to turn down your maintaining limit (lo limit on the boiler aquastat) as far as possible and still get enough hot water. This may take some experimentation.

featherz

Thanks for the suggestion . I thought of that option as well, but I saw others commenting that keeping boiler below 160f opens you up to creepy crawly issues (legionella) and/or condensation problems... thoughts?

JohnNY

I have a pre-coffee suggestion for Señor Bona.

What about piping the tankless coil outlet into an electric water heater, then lowering the boiler's aquastat enough to keep the boiler warm but let the electric heater elements pick up the slack when/if necessary?

Bob Bona_4

Sure Padre My thoughts were that op had 0 funds and it costs a lot of nothing to turn er down

I figure if they can pony up for an electric, maybe set that aside and save for the best option-the indirect.

I wouldnt worry too much about Legionarres with the tankless. You'll probably find 140 onthe dial about right, maybe a little lower-those controls aren't precision. I would worry about it if the boiler got shut on and off.

featherz

The indirect was a $2K option, so it's not in the cards for now. Hubby likes the idea of the cheaper electric, but I wasn't so sure it was the way to go. We've actually done ok with the tankless coil so far (we keep the house COLD in the winter) but every little bit helps!

I do appreciate the answers - I didn't want to end up with a rusty hulk o boiler metal to deal with.

Zman

Do you know your cost for oil vs electricity?
You could do a setup where the electric runs in the summer and the oil in the winter. This would reduce the standby losses in the summertime.
@Icesailor has posted a clever solution to this in the past.
Carl

featherz

Yes, that is what we were thinking. Just wasn't sure if there was a problem letting the boiler sit for six months. I'm also planning on 'working the numbers' to see if it would actually save any money when you figure in the electricity cost.

Rich_49

1 gallon of oil is roughly 140,000 BTUs . Electricity is 3,414 BTU per Kw . It takes 41.008 Kw to equal 140,000 BTU . If oil is 3.40 per gallon your electric rates have to be .098 per kilowatt to break even in what you'll spend to produce hot water . If the boiler is operating at 85% .

icesailor

Take that electric water heater and connect it to the boiler/tankless coil and use it as the heat source. It will save you a ton of money. For all the ones that I did, I never, not once had a complaint of a lack of hot water or higher cost over what was there before.

The installation should be less than what you paid the Vet for your sick cat.

I hope the cat is OK.

featherz

Thanks! So we would keep the boiler on, then run the output from the boiler/coil into the electric water heater, then out to the house? May need some help with that when the time comes (spring) - just to make sure everything looks correct before we blow something up. :P

As for the cat - I know we can't discuss prices here, but *he* cost more than the indirect water heater would have cost. /sigh Thankfully we do have pet insurance. His i-131 treatment (the main cost) is on Monday. Fun fun.

woodywoody

What about external, auxiliary heat? I have a large rural property with unlimited wood. Can I preheat the water coming from the pressure tank (we have well water) by setting up a wood burning fire source (rocket stove?) outside 50 feet from the house, plumb to have the water go through a copper coil in the rocket stove before going into the standard furnace. I'd like to have unlimited, cheap hot water.

featherz

(above post was from my hubby - I sent him here to read this thread).

icesailor

featherz said:

Thanks! So we would keep the boiler on, then run the output from the boiler/coil into the electric water heater, then out to the house? May need some help with that when the time comes (spring) - just to make sure everything looks correct before we blow something up. :P

As for the cat - I know we can't discuss prices here, but *he* cost more than the indirect water heater would have cost. /sigh Thankfully we do have pet insurance. His i-131 treatment (the main cost) is on Monday. Fun fun.

Good thing you don't have a horse. Worse than a high maintenance Teenager. Their only saving grace is that they don't sneak out at night, steal the car, get drunk and smash up the car, or get their girlfriends pregnant or themselves get knocked up. Mostly because all the boys lost their manhood long ago. You can housebreak a cat but not a horse. You can't ride a cat but you can ride a horse. Except, they are dangerous on both ends (They kick from one end, and bite from the other end) and uncomfortable in the middle.

They also don't become addicted to substances and need to go to He-Hab for drug treatment. They might need to be re-hab'ed for bad behaviors, but a lot of teenagers have that problem.

All in all, the cat is a cheap date. Entertaining too.

It is said: Horses Cause Divorces.

It is also said: A horse is cheaper than a divorce.

Or so it seems.

hot_rod

got any place to install solar? Use a solar tank with the optional electric element up top. Some nice incentives in NY right now for a variety of RE options. Sift through the ones that work for you here:

http://www.dsireusa.org/incentives/index.cfm?state=NY

Gordy

woodywoody said:

What about external, auxiliary heat? I have a large rural property with unlimited wood. Can I preheat the water coming from the pressure tank (we have well water) by setting up a wood burning fire source (rocket stove?) outside 50 feet from the house, plumb to have the water go through a copper coil in the rocket stove before going into the standard furnace. I'd like to have unlimited, cheap hot water.

I can think of a bunch of reasons not to use a rocket stove to make hot water unless your boiling it in a kettle.

Putting a copper tubing coil in there It will be a rocket stove all right.

SWEI

If you are serious about heating with wood, take the time to learn how. Modern gasifiers heat cleanly, safely, and efficiently, and as a side effect will reduce your cutting, splitting, and hauling labor by at least 30% over the typical outdoor wood-fired boiler.

Start with this, and come back with questions.

icesailor

EVERY ancient society that came before us today, cut all their trees down for lumber/building and firewood. Until they ran out of wood. Europe had pretty much cut down all usable wood by the 1600's. Germany planted the Black Forest and the Hertgen Forest for a supply of wood. America was pretty much solid forest from the Atlantic to the Mississippi River. Until it was cut down to send to England and build railroads and ships in the USA. When European explorers discovered the Polynesian Islands, they had been settled thousands of years before, the trees were already cut down, animals killed off, and the civilizations collapsed.

Its a really good and Green policy to cut down trees to burn wood to heat houses.

Unless you can replant cut trees and have them grow back as fast as you cut them down and use them.

Then, there's all that Carbon Dioxide they remove from the atmosphere and the Oxygen they replace it with.

Gordy

Where would we be today if not one tree was ever used to better civilization. Yes they were an abundant resource, and it is time to look to alternatives as to what we use trees for.

The OP just wants to make hot water economically. If they have trees as a resource acres of them then it is an option as Kurt pointed out a safe method.

Plenty of trees every day that fall, are dead, etc.

Solid_Fuel_Man

Ice, there is so much misinformation in your post I don't know what to say.......

Trees do use CO2 and make oxygen through photosynthesis, but when that tree dies is releases that stored CO2 into the atmosphere, so might as well burn it and replace some oil with it. Places that have cut themselves bare do exist, but that was long ago and in many parts of the world that is not a concern.

As a wood gasification advocate and user providing 100% of my heating and DHW for 3,200 sq ft. with a -45F design temp on 3.5 cord/year, there is no cheaper way to heat IMHO. Although the hardware and controls are not conventional, it can be done with off-the-shelf components and some internet shopping and out of the box thinking. With good crop cultivation I could grow and harvest that kind of wood on about 4 acres. In my area there is 58 acres/ person.

In my area it is foolish to burn oil and we are many miles from NG. Many pellet, coal, and cordwood users. Wood is not for everyone, but for many it is a very viable solution.

TS

Gordy

Wow 3.5 cords a year is not Shist.

Solid_Fuel_Man

Thanks Gordy,
It's been a lot of design to get there, but 100% heat and DHW is from 3.5 full cord of Beech/Maple/ Y&W Birch.

14BTU/ft2 @ -45F. Built the house in 2009. 3.5cord last winter, is what gets people interested in actually looking into spending some money on a real wood-burning system, none of the Home Depot/TSC junk wood equipment.

Taylor

icesailor

Not in our lifetime. Once they start seriously sucking that Nat. Gas out of the ground, they will dilute the underground gas pressure and there won't be any gas above the crude to push it up the pipe. So, they'll have to "pull" it up from 15,000' in the Gulf. Like the Mocondo Well that the cap blew off of. I want to see the size of the engine and the gearing to operate a working barrel, connected to 15,000' of lift pipe to operate the barrel.

Look at the Amazon Basin. As they cut the trees down to make way for Sugar Cane and other crops, they are finding roads and evidence of past civilizations. All failed when they ran out of trees to cut for building and cooking fuel. Its far more complicated than someone harvesting 100 years of wood off a less than 5 acre wood lot.

Gordy

Around my neck of the woods people get slab wood (waste from squaring up the log) from the lumber mill to feed their outdoor boilers. My firewood connection does tree trimming, and removal. He stores all that wood on his land. Every year he splits 30 cords to sell when it's gone he hops in the motor home, and heads to Texas. He needs to sell more because he's taking more wood in than he's selling. He's 72 years old still cutting trees.

And all that wood is trees that had to be removed. He use to have a mill to make oak lagging for shoring, and planking, pallets etc.


Obviously if your going to burn wood free is best option for supply. But at his price it would cost 950 bucks for 3.5 cords. Really that's still not bad for a year of heating DHW also.

Might be time to add a wood boiler categorey,and share your success solid fuel man. Instead of fielding questions to the hearth.com.

SWEI

I like it . Perhaps we could call the category biomass.

woodywoody

New York State is reverting to woodlands.

http://www.dec.ny.gov/lands/42065.html

There's plenty of wood.

icesailor

NY and any other State can clear cut their forests until they are deserts.

Is there any old growth virgin timber left in New York State that was there before 1620?

Its all been cut down at least once. You think I care? In a couple of years, I'll be taking a permanent dirt nap, toes up.

Waste not, want not.

Gordy

Your to awnnry, and boisterous for a dirt nap yet Ice.

SWEI

Sustainable timber harvesting is more than doable, but it does require that the landowner take a 'seven generations' approach to things. Leasing public land for less than the cost to build the required access roads does not qualify.

Solid_Fuel_Man

I'm all for a biomass category here at heatinghelp.

Can we make it happen Dan?

It's a niche market, and the controls and pipework need to be thought of a bit differently to make it legal and safe. But if done correctly the stigma of wood and tending to fires 24/7 and creosote dripping etc. is a thing of the past. I'm quite active on hearth.com, good bunch over there able to think out of the box.

Taylor

Gordy

I agree Dan. As Kurt suggested a "Bio Mass" category.

You have solar.

icesailor

Gordy said:

Your to awnnry, and boisterous for a dirt nap yet Ice.

Dirt naps are like having baby's. The first one come anytime. After that, they come 9 months apart.

Which ties into the #1 cause of premature death is birth. It come anytime after birth. Its the journey in between that makes life worthwhile.

Zman

The biomass category was a fine idea.
Unfortunately this post was abducted and taken there.
The OP was interested in the cost of oil vs electric vs cats...

featherz

True (OP), but it's still an interesting conversation.

Zman

Glad you found it...