So, the Rinnai heats the hot water AND the hot water for the radiators?

Lloyd: That is correct, through the use of the heat exchanger. I was very worried that it would not have the capacity to pump both and give us a decent, un-treehugger high powered shower and it did just fine this morning.

congrats lloyd, and WAY TO GO! lead by example.... did you get any rebates from the O.E.E??

Arg...I feel like I've made the energy/power distinction a million times on this website. I think you mean BTU/h, not just BTU.

This is great.
I am considering a tankless water heater.
One nice thing about a tank is that it is a stored source of water in an extreme survival situation.

"or wrap them in styrofoam"
i must say though, being an hvac engineer myself, more efficient equipment doesn't entirely make up for a lack of insulation. you need both efficient equipment AND insulation to fully reduce your heating energy consumption.

Congratulation on the retrofit. Sounds like you are going to save a bundle on your heating costs.



The next obvious step to save even more money would be to better insulate your home. Your Styrofoam comment didn’t go unnoticed, so I thought I’d chime in and let you know of an alternative that could work very well in your older home.



As you state that your home is 80+ years old, I assume there is some historic value. I also assume that you either do not want to or cannot afford to cut out the slat-board constructed walls to lay batt (fiberglass rolls) insulation between the wall and the exterior brick wall. (Assuming the outside walls are covered and are not the same bare brick)



The alternative is to insulate your home with expanding foam insulation. There are a bunch of ecologically-friendly types available.



Here is how it works. a contractor simply drills a 1” hole, usually with a hole saw, so the plug can be replaced and re-plastered in, then lowers a tube through the hole down to the bottom of the wall and slowly injects the foam through the tube from a canister the size of a bbq propane tank.



The contractor injects a measured quantity sufficient to fill the first two vertical feet * after expansion * into the lower portion of one wall and then moves on to the next prepared wall. In the meantime the foam quickly expands the base and rises up the wall to fill the area above, stiffens and begins to set. By then, the contractor has finished the first application on the rest of the walls and repeats the process until they are completely filled and insulated. You then have a well-insulated house, in 2-6 hours.



The disadvantage is that with install it costs about 5-10% more than batting, and really does need to be installed by contractor or someone who has a precise understanding of the behavior of the product. It cannot be applied directly to old uncovered interior electrical wiring,(if the wires are stapled or just clamped to a stud in the wall. It needs to be modern wiring in conduit tubing or a heavy PVC jacket) as the added insulation may cause the old wires to overheat and present a fire hazard.



There are other considerations, but A competent contractor can easily assess your house to see if this application is right for you.



The advantage of this means of insulation is that it is minimally invasive, has a good R-Value, fills cracks much better than other types of insulation and is very fast to install. In fact, because it is so fast to install you won’t have to pay for as many man-hours, and this helps somewhat to offset the increased cost of the product. Besides the fact that your house isn’t cold or drafty, you can’t even tell that the insulation is there.



Its good insulation, and I have used it very successfully on several occasions where tearing down and rebuilding walls to put in new insulation just wasn’t an option.



As I'm sure you know insulation will keep all of that costly heat from seeping from your home, so you can save yourself a bunch of that cash by just keeping what heat you have in the first place.



You also might want to look into purchasing new radiators, or having the old ones flushed and the interior chemically cleaned. The build up of calcium and other hard water deposits on the interior of radiators significantly reduces their efficiency.



My two cents. Hope it helps.


Mike J.

Lloyd Alter: in these solid brick homes, there is a cavity of only 3/4 of an inch between the brick and the lath, and it is usually so obstructed with mortar from the plastering that you cannot foam anything into the space. The only place where one can properly insulate without destoying the character of the house is in the roof. The biggest source of the heat loss is through the leaky old windows and aluminum storms; unfortunately the replacement window industry is structured around vinyl windows and everything else is prohibitively expensive in custom sizes.

Chris, you are of course correct. I have fixed it.

I have a Bosch tankless I've been using for just hot water the past couple of years... and absolutely love it.

I also have a house quite like yours, with a old converted coal furnace.

Are you getting enough heat out of your tankless to heat the house? And most importantly, did you do this or who did it for you?

Lloyd: I have had it for less than a day. I will do an update next week but it all looks fine so far. There is a link to the supplier at the bottom of the post.

Lloyd, there is one other way you can use foam insulation, if you cannot feed a tube down the wall. There are attachments for the tanks you can use, very similar to the needle attachment for a bike pump used to inflate a basketball or a grease gun. These are used to fill very small cracks around windows and doorframes, which would also come in handy in your situation.
My idea is, if you cannot fish a hose down the wall because of the plaster and mortar are blocking the path downwards, then you can drill a few very small holes in the plaster with a drill bit, very easily patched, and inject the insulation via the needle attachment, directly behind the wall. You might not get complete coverage, but every square inch/cm covered is going to be significant to slow the convective cooling, especially in the windward faces of your home.
The only other thing I can suggest is to consider adding an additional insulated layer-wall along the interior of the outside walls. It would decrease the room by approximately 3”, 7.8cm on exterior walls but surely increase comfort and add up to several hundreds of dollars of savings over the course of years. Plus, you can also easily maintain the appearance and feel if your home. Moldings and window edgings can be easily remounted after the thermal reflective sheeting, insulation and wall have been installed. This is a fairly common practice here in the U.S., often referred to as “super-insulating” because it is intended to act as an addition to existing insulation. In this case, it could bring your home to near average.


Mike J.

LA: this house has very loose old plaster- I would probably blow it off the walls if I tried to foam inside. I suspect that greater savings could be gained by reducing infiltration by getting new windows and insulating the roof, but thanks!

Wow, that is awesome! I've been reading about these heaters for a while and I can't wait for these to appear in more houses. Please do a follow up where you compare costs to last year's bills or even the previous month. I just hope you'll inspire more homeowners and builders.

would love to see a follow-up post in 6 months or a year that highlughted the running cost differences and any problems/benefits you found with the new system.
seems like you're also gaining quite a bit of space, which could be handy for some.

This is boggling my mind when I think of the space my heating and hot water apparati occupy in my basement. First there's the oil tank the size of a cow, then there's a cubic yard of oil burner, then there's the massive gas hot water tank, and finally there's that g*d* duct running half the length of my basement to bring the oil burner exhaust up the back chimney.

This kind of solution not only should save substantially on heating costs, but should free up a few square meters of floor space, and it doesn't even have to be connected to a chimney. I am simply agog. If one added such a conversion during general basement remodeling, then an entire room would be gained.

LA: actuallly, it is like getting an entire new room in my basement.

So your heat exchanger can handle two independent “heat sinks”? Who's the manufacturer?
I thought I was going to need two heaters until I read this article. Thanks!

Here's a quick story about upgrading and insulation:

Bought a house built in the mid-80's. Crawl Space insulation was poorly installed batts. Did some remodeling, installed a new boiler and indirect tank (Smith and a SuperStor), then blew a 6" cap of cellulose over the batts in the crawl space. Did some little things like sealed around electrical outlets and switches, replace a couple of doors. Went through a year and a half with all the upgrades, so I had a good record of oil consumption.

This past fall I had an air-change test done by my electric company, found all sorts of air leaks I didn't know about. I went nuts sealing everything I could.

As of now, my oil consumption is down 23% over last year on a week-to-week basis. Yep, 23%!!!

So the moral of the story is, if you're going to spend all that money upgrading, spend some time insulating AND sealing air leaks.

This is great for you. Im glad you did it. My only problem with things like this is that the energy required (and pollution emmitted) to make that thing is generally not justified by your savings. Same goes for buying a hybrid car (which i own, since we were buying a new car anyway). The fuel savings for me neither pays for the cost differential nor the energy used (and polluiton created)to make the car.

If you were building a house anyway, then instal one of these suckers. Good idea. If you are buying a new car anyway, then buy a hybrid. But switching over to a more economical system generally does not lower TOTAL energy consumption (must include pollution in your energy calcualtions)

The old addage is best, reduce, reuse, recycle..in that order.

just my two bits.

Lloyd your boiler room looks amazingly familiar. Our 75 year old brick house has a gas boiler and radiators as well. Unfortunately, ours is steam and I'm guessing yours is hot water. We try to utilize our wood stove to keep our monthly gas bill down to less than 3 hundred. Neighbors are spending 480/month with the thermostat down. Painful.

R.Hirsch, those are noble thoughts about energy expended to build the equipment, etc. but when it comes to blowing several hundred bucks a month for a gas bill, some of those considerations have to take a backseat to lowering the amount of money flowing out the bank account.

"My only problem with things like this is that the energy required (and pollution emmitted) to make that thing is generally not justified by your savings."

I would tend to disagree with that in the case of the heating system of a house.

Sure there's energy that goes into the production of the system, but that amount is not infinite. Even if it takes longer for the energy investment to "pay" for itself through savings than the money investment, it still will, especially in a house that will stick around for decades.

If the system mentioned in this post takes 50% less energy than the previous one, that's quite a lot. 50% of the energy used by a house in 10 years or in 25 years almost certainly is more energy than what it takes to produce and ship such a system.

Cool article. I agree the next step is insulation but also water conservation: shower and faucet aerators can help you reduce you water use thereby less water to heat.

Fantastic! My question: how does one locate a heating contractor who can spec, install, etc. these kinds of systems? I'm out here in the boondocks of the Bronx, NY, and the local contractors think I'm speaking Finno-Urgic when I mention tankless heaters, etc. Is there some kind of directory or url to help locate energy efficient specialists? Thanks.

Hi all- I'm a heating contractor in Baltimore specializing in older steam and hot-water systems, and stumbled upon this thread. I'm glad to see so much interest in efficiency!

I invite you to join us on "The Wall", a message board which you can find on my friend Dan Holohan's site www.heatinghelp.com. There you will find a group of like-minded people, from home and building owners to contractors and manufacturers' reps. To me, this group is the best in the business.

There also you will find "Find a Professional" which will put you in touch with contractors who can help you make some of your efficiency visions come true. I'm not sure what experiences you've had with contractors in the past, but there really are good ones out there.

Come on over!

"At the top is the double walled flue, bringing combustion air in the outer layer and exhausting through the middle."

Do the intake and exhaust both come from outdoors? The picture makes it look like they vent into your basement.

The picture was taken before the installation was complete. It now goes outside.

Great website, useful information. I was looking for ways to save some on my energy bill.

-Brendan

Update: after a week of calling, questioning, etc., I finally tracked down a plumbing contractor in the Bronx who could install the tankless gas water heater. They started work on a Monday. It was pretty clear that they didn't have much experience with tankless, but were eager to get some. Ripped out the old boiler, repiped, vented, and electrified everything and installed the water heater.

No hot water. After a couple of days of trying to figure things out - - gas pressure, water pressure, venting, etc. - - a Bosch rep. came around and looked at the installation and tested everything. Turns out the heater was defective. New heater - -latest model - -installed and, voila, instant and endless hot water!

It's been a couple of months now and I'm very happy with the tankless. Super fast hot water. Endless supply. Lower bills. My only complaint would be that claims notwithstanding, the tankless does seem to have some trouble with more than two applications at a time . . .especially if one is a bath or shower. But, we are only three in the house so not a big deal.

Lloyd, I assume you are in Toronto, like me. Would you recommend the installer you used? If so, please send me the information. Thank you!

LA: there is a link to Ecotech at the bottom of the post.

Ecotech has changed their address:

http://ecotechhydronics.com/

I live in Massachusetts and after reading this article and commentary called a local Rinnai dealer who said that it was illegal to use these hot water heaters for home heating here. I'm not sure why that should be. He also noted that hot water for normal use needs to be heated to 120 degree Farenheit, while water for radiators needs to be heated to 180 or 190. Does your system provide the two different heating levels simultaneously?