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Tankless Water Heater - Part 6 - The Decision?

May 24th, 2008 · 4 Comments

In Part 5 we revealed the two quotes received from two separate companies to install the same Rinnai natural gas tankless water heater.

I won’t repeat all of the details from the two offers here (use the link to Part 5 above to see the comparative details), but to me there was clearly one offer which was less price and had better warranty.

This is new technology to me, even though tankless water heaters are much more the norm in Western Europe and else where. Hot water tanks are more of a North American phenomenon.

The Canadian ecoENERGY Residential Retrofit program currently provides (Federal and Provincial grants combined) for a $500 grant (increased from $400 January 1, 2008) for a home owner participating in the program who installs a tankless water heater with an efficiency rating of 0.8 or higher (for which the Rinnai qualifies).

Our decision: Neither. Let me explain.

The aforementioned grant is available for our household until May of 2009. Why? Well, as part of the ecoENERGY Residential Retrofit program you have to have two energy efficiency assessments (i.e. energy audits); the first ‘D’ energy audit performed by accredited firms before you undertake any renovations and the second ‘E’ energy audit conducted within 18 months to determine which recommendations from the ‘D’ energy audit report were actually undertaken and to what extent. [for more information on the ecoENERGY Residential Retrofit grant program, simply select the ecoENERGY Retrofit Grant link in our blog roll).

We had the ‘D’ energy efficiency assessment conducted in November 2007, so that would make May 2009 (if my math is right) the 18th month thereafter. Make sense?

So, we are in no rush to undertake energy efficiency renovations for which there are applicable government grants; unless the Canadian Federal abruptly changes the rules of the program retroactively. They wouldn’t do that, would they? :-)  Surely, I digress. On this one I’ll take that risk.

Now, our main concern are two fold. First, special venting is needed not just for the Rinnai model but any natural gas tankless water heater. Both firms indicated that they could not install the Rinnai at the location of our current hot water tank, which is conveniently located in the center of all of the bathrooms, kitchen and laundry room areas of our home.

Proposed Tankless Rinnai Location

So, both said that it would need to be installed against the outside wall (see above picture) where the current natural gas enters our home, about 30-ish feet away. Anything that needs such special venting causes me a concern, especially when we have our current hot water tank vented 30-ish feet away from an outside wall with no issues.

Second, installing the Rinnai hot water tank 30 feet or so away from most of the sinks, bath tubs, showers and dish washer (and clothes washer, although we do most of our laundry using cold water) will result in a waste of a lot of water each time someone turns on the hot water tap. Thirty feet of water is a lot of water for each shower, bath, etc.

While arguably not necessarily a non-renewable resource such as oil or natural gas or uranium, environmentally water remains a precious resource. And, the more water we waste in our home the higher our water bill costs will increase.

Yes, we missed out on the $400 or so difference in the offer from the lower priced firm. They had a $500 sale on which has now ended (their original cost was $100 more than the first firm, hence only a $400 or so lower net price). That’s OK. I’d rather take my time and focus more on this when I have the time (right now I am more focused on spring types of outside activities such as ‘renovating’ our front garden, replacing the current undersized gutters, exterior hidden screens for our front and rear door, as well as fixing our darn en suite shower leak.

The last thing I need is to install a new technology without sufficient research and have the family members complain that the hot water takes too long before they can start their shower.

We will come back to tankless water heaters in the fall. Who knows, we may just keep our current hot water tank. Or, perhaps we will use a different technology altogether. Or, perhaps we will go back to the Rinnai and just absorb the wasted water.  :-) Remember, I am after both reduction in the costs of ‘running’ our home as well as energy efficiency and environmental appropriateness combined.

To continue with the next article in this series, yes before the fall time :-), simply select this link to Part 7.

Tags: Basement · Energy Conservation · Tankless Water Heater · ecoENERGY

4 responses so far ↓

  • 1 Jim Mcgoldrick // May 25, 2008 at 8:03 am

    Rinnai can be inside and vented to outside however the cost would scare you as you are doing a retrofit. Wasted water can be recovered by several devices on the market that allow water to be hot on tap all the time, once again an extra cost. Yould fit a pomp to the outside rinnai and fit a return line to the existing hot pipework, this would stop the 39 metre dead leg you describe. Again an extra cost but all your concerns be overcome. I would recommend rennai to anyone as it is a top product and you should get 30 years from it with little trouble.I would ask rinnsi to reccomend to you a quality installer.The basic principles of this system has been around for 25 years in one form or another. The reason the installer wants to put appliance outside is the ease of venting the carbon monoxide gases. This is required on all gas appliances and does not make them unsafe. Many quality safety devices are fitted to Rennai products. Good luck

  • 2 Dan // May 25, 2008 at 10:56 am

    Hi Jim,
    Many thanks for your insights. Here is where my head is at.

    Yes, there are firms that can supply ‘hot water on tap’ so we don’t loose 30 feet of water with the increased distance between the suggested Rinnai unit vs the curent hot water tank. My question is why would I have to bother? This is such a change for me that the last thing I need is yet another device to worry about.

    Second, then there is the financial impact; another device means as you rightly say more cost to me and the payback is already approaching 5 years which is a long time for such a large $$ investment.

    Lastly, the two installation firms were authorized Rinnai resellers and installers.

    Once we finish with our outside renovation and ceiling leak repair, we will again tackle the tankless water heater. There has to be a type of unit which meets all 4 of our goals as outlined at the beginning of this series of articles, including medium term financial payback. To me more than 5 years is beyond a medium financial payback.

    Dan

  • 3 Rachael // Mar 7, 2010 at 1:27 pm

    Hello Dan:

    What is your opinion on a greywater recovery system?

  • 4 Dan // Mar 7, 2010 at 1:43 pm

    Hi Rachael,

    Thanks for your question. I assume you are referring to a Drain Water Heat Recovery (DWHR) system?

    Personally, I quite like them. Why?

    I like simple.

    I like energy (and water) conservation products which do not use a lot of technology or moving parts (compared to, for example solar water heaters and solar PV panels which typically see the manufacturer’s product warranty expire well before the typical consumer’s investment has been repaid through savings by reduced utility bills).

    We would use one except the prior owners of our home placed the basement bathroom such that where we would put the DWHR pipe is right behind the drywall and the sink! Therefore, there would be a lot of demolition and reconstruction of our basement bathroom in order to install any manufacturer’s DWHR unit making it not economical for us.

    If you want to read more about this type of energy conservation device, you can review our prior articles on it here:

    http://dailyhomerenotips.com/2008/01/20/ecoenergy-report-followup-drain-water-heat-recovery-dwhr-device/#more-180

    http://dailyhomerenotips.com/2008/02/11/dwhr-drain-water-heat-recovery-follow-up/

    Cheers,
    Dan

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