Heating with Wood, what to do about Hot Water

[mudsliders]

I am new to the forum. Lots of good info. I have been heating my home with a Jotul Oslo for three years now. My hot water still comes from a tank-less oil fired boiler that was used for water and heat. I am looking for a more efficient way to heat my water. I have seen setups that use the wood stove, but I am not so interested in anything like that. Are oil fired water heaters/tanks appreciably more efficient than my 12 year old tank-less oil boiler? Just looking for options/direction. Thanks. Ray

 

[babalu87]

I'm in the same boat Ray
I am looking into a passive solar that will at the least assist the boiler in turning out hot water as well as a boilermate and maybe even just a storage tank in the basement that will keep the water warmer than it is when it comes out of the well.

I do want to continue to have the boiler heat the water in case I ever need to go back to it for any reason (vacations ETC) just so I know the whole system works properly.
Once you let a system like that go dormant you will have nothing but issues with it when and if you ever need it again.

 

[elkimmeg]

Boiler. furnaces should be cycled like any engine and not left completely dormaint, Wood stoves are great for shutting off your boiler on the flip side a tankless boiler running in winter was almost free hot water. This post has been addressed many times before when the boiler cycles without a demand that is to heat the fire box.
There are other measures that one can do to reduce bioler cycling. One can install a motorized damper. This closes after the combustion cycle and prevents heat escape up the chimney
with the firbox holding heat longer there is less cycling. Boiler mate still neers a heating coil to hold the temps so I don't know if energy is saved. Thge boilermate is really a tank that supplys an extra reserve to help with peak hot water demand. One could consider an oil fired hot water tank they are as effecient as you oil burner probably using the same type of firing head But plau on over $1200 for one installed maybe more If you have a small demand it is possible electric might save some money. Solar is a possibility but few systems supply all hot needs for a familly
Even with tax incentives 15,000 could be a reality for a fully installed system. If you are like me Idonot have that money laying around. Cornell, Villanova, and Wheaton drained all my accounts.
I would not be rebuilding used stoves to install here. I have a new red Encore Ever burn stove sitting in my, shed I would die for, but I can not afford it. It will be donated..

Money and work in the construction trades is tight now I'm watching my spending.

 

[babalu87]

There are other measures that one can do to reduce bioler cycling. One can install a motorized damper. This closes after the combustion cycle and prevents heat escape up the chimney
with the firbox holding heat longer there is less cycling

Elk, I would appreciate any further information (link) on the damper, thanks.

 

[elkimmeg]

They really work and do the job I mentioned Last year at this time we had this discussion I think Rome supplied links to manufactures I will check to supply a link to that post

Oil burners can be made more effecient. The motorized damper is one improvement basically it is wired in to open just before the combustion cycle and x seconds after it closes. Thus preventing continued heat loss up the chimney

 

[Andre B.]

Some day I will get this setup. But it will likely be in the machine shop, lot's of hot water for washing tractors and stuff.
http://i73.photobucket.com/albums/i208/andre_b/Auxiliary Equipment/Waterheater1.jpg
http://i73.photobucket.com/albums/i208/andre_b/Auxiliary Equipment/Waterheater2.jpg
_______________
Andre' B.

 

[Rhone]

Tanked systems are more efficient but that depends on how you use it. Older tankless oil systems (not to be confused with on-demand) store a little bit of water inside them it keeps at temperature. You won't run out of hot water and there isn't a pump, and if installed correctly it has a flow limiter. If you try to pull more hot gallons per minute than the boiler can handle it reduces water pressure for everyone instead of everyone getting colder than expected water. That's helpful when it happens during a shower. You usually have more standby loss with tankless compared to tanked systems. 12 year old units usually have a barometric damper so your chimney is always drafting. That is, you always have air flowing over the water coils in the tankless system, and though they make automatic vent dampers instead to help correct that situation I can't find any that are compatible with oil systems they say GAS ONLY. Interesting that they come in todays new oil tankless systems but aren't offered as a retrofit to older models. Todays tankless boilers with flame retention, sealed combustion, and vent dampers are much better than the older. A tanked system, as mentioned requires another pump but there isn't cold air blowing across the water and the longer your boiler stays on the more efficient. The 1 minute your tankless boiler clicks on to reheat the several gallons of water inside it aren't as efficient as the tanked version keeping the boiler going for several minutes.

There's a few things you can do.
1.) Get a tank insulated with at least 1" foam insulation (R10) which should reduce your costs. If you do, adding a tank wrap will add very little savings and isn't recommended though with the costs of oil now, it may be worth the investment.

2.) Since the tankless system takes 5-7 minutes to warm up from a cold start, shut it off when you don't want it and turn it back on when you do. This is the option we do. We turn it on in the morning, take our showers and turn it off. At night, we turn it on until it comes to temp and shut it off for the night. It gives us enough hot water for washing our hands, etc. and have very little standby.

3.) Get a waste hot water recovery system, something like http://www.gfxstar.ca/englishindex.html or (broken link removed) which recovers energy from the hot water wasting down the drain. Only works when using hot water and having it go down the drain simultaneously such as showers but expect about a 30-40% savings when doing such tasks. For us, at $700 for the gray water recovery unit and showers account for 75% of our hot water if it only recycles 30% of that energy that's $210/yr+ savings. That's worth it.

4.) Get a solar hot water system. This system http://www.radiantsolar.com/domesticHW.html costs $3,300 and you'll get a tax credit of 30% on most of the price. Expect it to supply probably 50-60% of your hot water, 40-90% under special circumstances.

 

[babalu87]

3.) Get a waste hot water recovery system, something like http://www.gfxstar.ca/englishindex.html or (broken link removed) which recovers energy from the hot water wasting down the drain. Only works when using hot water and having it go down the drain simultaneously such as showers but expect about a 30-40% savings when doing such tasks. For us, at $700 for the gray water recovery unit and showers account for 75% of our hot water if it only recycles 30% of that energy that's $210/yr+ savings. That's worth it. .

After a hard night of draft beer, jalapeno pizza and buffalo wings I may get more heat from the toilet than the shower :gross:

Googling AUTOMATIC FLUE CLOSING DEVICE isnt doing much for me :red:

 

[Rhone]

Yeah babs, that is gross!

I've looked for a year to find an automatic vent damper for my oil tankless. With my insert going, it speeds up the draft in my oil flue as well which causes excessive amounts of cold air blowing over the coils and I get very excessive idling of my tankless oil boiler.

There's 2 automatic vent dampers I've found as a retrofit, the Honeywell and Effikal, of the two the Honeywell has a more tight design but both are gas only. I've been looking for an oil one as a retrofit for a year now, I've given up

 

[babalu87]

Yeah babs, that is gross!

I've looked for a year to find an automatic vent damper for my oil tankless. With my insert going, it speeds up the draft in my oil flue as well which causes excessive amounts of cold air blowing over the coils and I get very excessive idling of my tankless oil boiler.
There's 2 automatic vent dampers I've found as a retrofit, the Honeywell and Effikal, of the two the Honeywell has a more tight design but both are gas only. I've been looking for an oil one as a retrofit for a year now, I've given up

Thanks.

You have a boiler AND a wood burning device on the same flue?

Honeywell mentions GAS boilers, I would imagine it can be used for OIL fired as well?

Hell I could probably figure something out and build one??????????

 

[Rhone]

No, not on the same flue. I did for 25 years in my other house!

It's difficult to explain what's happening but I included a picture to try to explain it. I've hard a very hard time explaining it to other people at work while others think it's really simple.

Think of two square metal tubes welded together, and you send heat up one of the pipes. The pipe with the heat is going to warm up, and some of that heat is going to transfer over to the other pipe next to it since it's connected. That's pretty much what happens. As my insert warms up it's masonry flue some of it's heat conducts over and warms up the flue the boiler is on and it starts drafting better. Since I have a tankless, the more the boiler flue drafts the more air travels through the boiler to cool down the water causing excessive idling in winter with the insert going. It's not a little either, in a month I used my insert and no oil for heating I went through 79 gallons for idling when I normally go through 19. That's why I started shutting it off and found out, it only takes 5-8 minutes to go from stone cold to reaching the high point water temp. I turn it on in the morning and before I'm done eating breakfast it's done heating the water. I shut it off, take my shower and I have about 15 minutes of hot water and then I get dressed and head to work. No standby loss. Same with doing dishes, I turn it on, 5-8 minutes later it's hot. I shut it off, start up the dishwasher and have very little waste. But, I don't think many families are willing to do it that way, I just wasn't willing to pay an extra 50-60 gallons/oil a month in winter to keep the boiler idling and we got used to it. Everyone's house and situation is different, and it only matters if you have a chimney with multiple flues and one is heated with wood, another an older tankless model. It's at a point now when we go to others houses we're not familiar with the sound of the boiler turning on for no reason anymore, and when we want to take our showers and we're staying at someone's house it takes us a second to realize we don't need to turn on it on first. One of those things, like driving a manual car that after a while it becomes a subconscious thing. I want the vent damper because, even with the boiler off it's still sucking air out my house and I'd like to stop it.

 

[elkimmeg]

What about a delayed Action Solenoid? What it does is delay the introduction of oil in the fure box for 3 to 6 seconds air is introduced and sets
uo the draft prior to oil and iginition. This endances a more cloplete combustion lesssote less chance for dackdraft
plus improved effecienccies

 

[babalu87]

............. It's not a little either, in a month I used my insert and no oil for heating I went through 79 gallons for idling when I normally go through 19. That's why I started shutting it off and found out, it only takes 5-8 minutes to go from stone cold to shutting off because the high point water temp is reached. I turn it on in the morning and before I'm done eating breakfast it's done heating the water. I shut it off, take my shower and I have about 15 minutes of hot water and then I get dressed and head to work.

I think I'll snake a wire and put a switch for my boiler in the bedroom.

Off at bedtime and on when we wake up.
We'll know we forgot if the shower doesnt get hot in a minute