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A blog about how Canadians can achieve energy independence by powering down and then powering up the right way.

What you should know about water heating in your home

Submitted by TheVillageGreen on Wed, 11/25/2009 - 10:57

I was on the phone this week with my friend Valerie who told me the water heater in her basement burst the other day.  A couple of months earlier, the same thing happened to my friend Jennifer in her condominium unit.  

I decided to riff about water heating today because, according to my research, about a million water heaters currently in Ontario homes are ready to do exactly what Jennifer's and Valerie's did, costing hundreds or even thousands of dollars in damage and clean-up.  

Of all the energy used in the typical Canadian home, roughly a quarter of it is used for hot water heating – washing dishes, baths, showers, that kind of thing.  Hot water heating is a huge energy hog and it’s a huge profit centre for the utilities that rent us those tanks.  

According to Natural Resources Canada (NRCAN), the useful life expectancy of most electric water heaters is around 13 to 15 years and about 12 years for natural gas operated systems .  

What’s more, according to NRCAN’s Survey of Household Energy Use 2003 (published in 2005), 45% of the homes in Ontario have water heaters 11 years old or older. 18% of water heaters in Ontario homes are 21 years old or older.  And, 34% of homeowners don't even know how old their water heaters are.  In other words, about a million water heaters in Ontario homes should be replaced right now!


How efficient are water heaters?  Or, does this cost me money? 

The efficiencies of traditional water heating systems vary widely depending on make and model, the fuel used (electricity or natural gas) and the age and condition of the system.  Electrical systems are generally more efficient than natural gas systems.  

According to the US Department of Energy a typical 40 gallon gas fired tank will be between 42% to 86% efficient with most being less than 65% efficient.  Electric fired tanks are around 70% efficient.  In both cases, system efficiency drops (dramatically according to some experts) over time as residue and corrosion build.   

What does this mean? 

This means three things:  

  1. The utilities that rent these systems are making a fortune renting systems well past their useful life. 

  2. The utilities make even more money selling you all that extra energy as a result of that old inefficient system.

  3. The utilities cannot be counted on to give you good energy efficiency advice or rent you the best systems because they are in a conflict of interest.  In other words, the more energy you use, the more money they make.  

Cheap trick

  1. Check the age of your water heater.  It can be found on one of the tags on the outside of the heater.  

  2. If it’s significantly older than 10 years or so in age, it likely needs to be replaced.  Not only are old tanks inefficient, they can burst as a result of corrosion like my friend Jennifer’s did, costing her hundreds of dollars in damages to her condominium. 

  3. If you can, buy your system outright and have it installed by a reputable contractor. Check out the new on-demand water heaters.

  4. If you rent another system, ignore the rep in the call centre at the utility when he tells you they don’t replace tanks that are still working.  Most utilities have open ended contracts that do not specifically state when tanks are to be replaced. 

  5. If you replace your heater with a contractor, the utility you’re renting from is required to pick up the old heater.  They will demand a service fee.  Ignore them and be persistent.  According to their rental contract (generally open-ended) they own the tank.  You’re simply   returning it. 


Gabriel Draven 

Comments

I have installed a Navien on demand hot water heater in our household. The particular system that I have includes a 2 litre recirculating feature which can be set on timer to provide direct recirculating hot water should you require it at initial demand time (ie Mornings). We have chosen to not use this feature and actually have not noticed any time difference between the on demand and our previous 50 gal tank in providing hot water to our faucets. Our particular unit is 94% effficient is wall mounted, virtually silent, direct venting, and pulls its combustion air directly from the outside of the building envelope, therefore does not draw air from the inside of the house to com-bust and then merrily send it on its way outdoors in the dead of winter. The Unit comes standard with a 12 year warranty(CR models: 12 years on heat exchanger, 6 years on parts) and was installed complete for $3,200.00 CDN. This Cost included some re-plumbing as I moved its location about 20 feet. Our local Gas Utilty has reimbused us with a $300.00 CDN cheque as a result of an upgrade program they ran. I am receiving a further $634.00Cnd as part of the Home Energy Audit program. The Unit it replaced was a rental costing us aprox $26.95CDN a Month (High efficiency 50 gallon direct venting but internal air supply) As I am on Equalized billing and have a Gas Fired boiler I have not been able to break my relative consumptions down as of yet so cannot provide any hard numbers in this case. The Money In deciding which way to go I crunched some numbers. to do nothing and continue with my current system was going to cost me $3880.80 over the next 12 Years in Rental Fees. Currently legislation is pending that All Gas fired appliances in Ontario will require annual inspection and re certification. Insurance companies have already stated that these inspection certificates once mandatory will become part of home owner obligations to maintaining your household insurance coverages, (bursting water damage, CO2 leakage etc). Failure to having this annual maintenance inspections will result in your insurance being null and void in case of mishap. With this in mind I have contracted proactively to have annual Maintenance inspections with my installers on my gas fired equipment for the next 12 years. This will cost me 100.00 a year therefore $1200.00CDN. It is not exactly clear as of yet how this will apply to rental equipment, I believe it to be fair to assume that if the Rental companies are mandated to perform these inspections the rental costs will be adjusted to reflect this. If the burden falls on the householder then the costs will be direct. Either way this surcharge will be passed on. Option # 3 for me was to rent a navien through my local equipment vendor. At that time (and Currently ) the going rate for a non circulating Navien CR180A ( My unit is a CR210) was 36.95 a month (not sure how HST is going to affect this price) or $5320.80 over 12 years, plus abt $800.00 to relocate the unit on an outer wall. In summation Purchase: 3200.00 + 1200.00 (Mtn) - 300.00 (enbridge rebate) - 630.00(EAR)* = $3470.00 over 12 years Do Nothing $3880.80 (possibly min 600.00 MTN) = $4480.80 over 12 years Rent Navien 5320.80 plus 800.00 installation plus 600.00 MTN -300 rebate = $6420.80 over 12 years No matter how you look at it the numbers told me that purchasing outright and turning the maintenance over to my very trusted installers was at least economically less expensive. None of the numbers include any expected gas usage between relative technologies. One last comment on Water usage. Since I know that I am in Direct control of my water heater and that the energy that it consumes is directly tied to me opening and closing any hot water tap my consciousness of hot water usage has skyrocketed. I have direct control over when my hot water heater turns on and when it doesn't. I may have an unlimited supply at my disposal but I also feel that I have direct control over how much that luxury is going to cost me. One mans perspective Robin
Submitted by Robin (guest) on Tue, 12/08/2009 - 13:03.
I think there's a lot of misconceptions about on-demand water heaters that we gladly accept in Canada because we are among the most lazy, spoiled and wasteful people on the planet. I have a study somewhere on my hard-drive that was done by BC Hydro. It found that on-demand water heaters had about twice the useful life expectancy of conventional heaters and, maintained properly, would reduce energy usage by about 40%. They are used in pretty much every country in the world except here in Canada and the US. - Gabriel
Submitted by TheVillageGreen on Fri, 12/04/2009 - 11:32.
I am told on North American demand heaters only produce 4 gals/min? I don't understand why they are so expensive and? inefficient , they've been used for years in the UK, and I believe are tied in to central hot water heated radiators. I know my Mum had an amazing programmable unit she easily got the hang of running when she was well into her 70's.
Submitted by britjan (guest) on Thu, 12/03/2009 - 23:31.
Extend the life of your hot water heater (double the life) by flushing it once a year. Here's a site with instructions to flush your hot water tank... http://www.greenterrafirma.com/flush-water-heater.html Turning down the temp and using a blanket are also great suggestions.
Submitted by Bruce (guest) on Thu, 12/03/2009 - 22:21.
Try shutting off the breaker on your electric hot water tank, and see how many days you can go without turning it back on. Great saving's in energy bills.
Submitted by Anonymous (guest) on Thu, 12/03/2009 - 20:34.
Anyone looked into using a ground or air source or waste water heat pump?
Submitted by Scott (guest) on Thu, 12/03/2009 - 16:00.
Natural gas's problematic cuz it's already hit its' peak production and wells in North America are rapidly drying up.
Submitted by Rapid (guest) on Thu, 12/03/2009 - 15:43.
One of the problems with comparing natural gas and electricity fired systems is that the fuel sources have different energy densities. So while electric-fired tanks are generally more efficient, as some of you point out, the natural gas systems can be less expensive to operate. One major distortion at the moment is the price drop in natural gas over the past year and a half. We are doing analysis now for clients (just completed one this morning) looking at commercial-scale solar water heating systems. The economic modeling is completely different (worse) than the modeling we were doing about a year and a bit ago because of these price decreases. I would note that this is a very temporary situation and that the outlook for natural gas supply is actually quite poor in our view, all this talk about shale natural gas notwithstanding. - gabriel
Submitted by TheVillageGreen on Thu, 12/03/2009 - 15:10.
You'll need to upgrade your electrical service if you want an electric tankless. I don't recall how much exactly - but it's something like 100 amps (just for the heater), or maybe it's even 200 amps. I don't recall. Anyway, see my previous comment about on demand water heaters (gas) being a big rip off.
Submitted by Scott (guest) on Thu, 12/03/2009 - 14:55.
On demand water heaters are a rip off. They are expensive. The payback is ~17 years by my calculation (assuming heat loss from an upright of 100 watts). Buy a water heater blanket for $30. You'll actually save money that way. (Keep in mind too, that any heat loss from your water heater is also heating your house in the winter, so it''s not all lost. ;-). Plus heat on demand lets all your family members take half hour showers instead of 5 minute showers..... Heat on demand will not likely save you any money. It could even cost you a lot more!
Submitted by Scott (guest) on Thu, 12/03/2009 - 14:52.
Scott, Why would a whole family would change their bathing time habits by getting a tankless installed. In regards to tank efficiency, according to NRCan, - Natural gas tank, natural vent, with pilot 55% - natural gas tank with the electrical blower on top, 57% - tankless, condensing, 92% this means that 55 parts of the 100 parts burned of natural gas goes to the water in temperature increase, the other 45 parts are lost through the tank flue. also, when you are away at work or school, the tank keeps reheating and using natural gas, just to keep water at 60C, tankless wont work until you actually open the hot water.
Submitted by Joe (guest) on Sat, 12/05/2009 - 22:11.
Electricity is generated using natural gas, coal, hydro, wind, nuclear, ... The each of these modes of generation has its own efficiency range. Plus, there is power loss in the transmission of electricity that has to be taken into account. I buy wind power from Bullfrog Power. It's a little more expensive - about 25% (~$0.15 vs ~$0.12/kwh), but to me it's worth it. I'll be switching my gas fired rental unit by purchasing an electric one outright, soon. The money saved on rental fees will cover some of the extra cost for clean wind power.
Submitted by Scott (guest) on Thu, 12/03/2009 - 14:45.
What about the water on demand water heater? They are more costly but alot more efficient in the long run. As the name says, it only heats the water when there is a demand for it. The savings comes from not having a 40/60 gallons water constantly being heated for nothing. Also, verify the temperature set on the water tank; it is on high temperature unnecessarily.
Submitted by Anonymous (guest) on Thu, 12/03/2009 - 14:34.
I'm looking to change for a tankless hot water system, electric since I don't really have the space for a propane tank, do you have any figures on how more efficient it is as opposed to a 60 gal. electric hot water heater ? thanks
Submitted by mIke (guest) on Thu, 12/03/2009 - 14:29.
I am no expert, but it is my understanding that gas water heaters are far more efficient than electric - substantially. And it is true that the new water heaters are far more efficient than older ones - we just got a new gas heater and are supposed to be saving 25%+.
Submitted by Anonymous (guest) on Thu, 12/03/2009 - 13:27.
No, the regular gas water tanks are really less efficient compared to the electric ones, because some of the heat is wasted through the flue. But even so, heating water with gas is *cheaper* than using electricity, because the electrical energy is around 2 times more expensive (if I'm not mistaken) than the same energy obtained from natural gas.
Submitted by Vasile (guest) on Thu, 12/03/2009 - 13:40.

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