[Greenbuilding] hot water heating options

Tue Oct 3 08:13:57 CDT 2006

Hi Keith and others,

  Thanks for your suggestions. To clarify: The house is currently unoccupied, but the non-profit expects to sell it to a couple with one or two kids. The laundry (washer/dryer) is right next to the full bath on the second floor. The half bath is right next to the kitchen on the first floor. The half bath and full bath are lined up vertically (more or less).

We are leaning towards the tankless gas system, but are concerned about the capacity limitations. Anyone have experience with these care to share?

  Our second choice would be an electric tank unit for it's efficiency and lower standby loss.

  THOUGHTS???

  Cheers,
  Bambi 

Message: 3
Date: Mon, 02 Oct 2006 11:26:07 -0400
From: Keith Winston 
Subject: Re: [Greenbuilding] Hot Water Heater options
To: Greenbuilder list 
Message-ID: <45212F8F.4000307 at earthsunenergy.com>
Content-Type: text/plain; charset=windows-1252; format=flowed

Hi Bambi! Your choices (as if you didn't know):

Hi-eff. gas tank unit, 90+% combustion eff., standby loss takes system 
efficiency probably 10-20% lower, $600-$3000
Elect. tank unit, nearly 100% eff (though electrical generation is only 
35% or so), somewhat lower standby loss (no flue), $250-500
Gas Tankless, no standby loss, combustion efficiency 85%, $1000-2500 
(flow delays and capacity limitations are occasional complaints with 
tankless/on-demand heaters)
Electric tankless, nearly 100% efficient, same generation caveat, no 
standby loss, $4-600 (same flow-delay caveat, also they require a BIG 
electrical circuit)
Heat Pump Water Heater, probably > 200% efficient BUT uses indoor air so 
gives you free AC in the summer BUT adds heating demand in the winter, 
must be coupled with tank (some units include tanks), probably 
$1200-2000 installed (Watt$aver has mixed reviews, includes tank, trade 
price around $1300: Nyletherm 110 has somewhat more complicated install 
& requires additional tank, unit price around $900 
http://www.nyletherm.com/waterheating.htm)

Ah, and of course, SOLAR. Good fit with any tankless, potentially good 
fit with tanked backup systems. Federal tax credits. System cost, before 
fed & state credits, $5-8000. Efficiency through the roof in a good 
install in a favorable location.

Finally: if all your fixtures are within 20 feet of each other, they 
probably all go down the same stack? Are they all out of the basement, 
that is (particularly) is your washing machine somewhere other than the 
basement? It is quite likely that installing a gravity film exchanger on 
your waste stack is a no-brainer with every system above. Installed cost 
something like $1000, requires 3-5' of vertical stack, with as many 
fixtures flowing through that section of stack as possible. 
http://gfxtechnology.com/

I don't stand by a single number above! This is all off the top of my 
head, so it might help orient you/others, but I don't guarantee anything 
here is accurate! Specifically, I await all kinds of arguments about the 
real level of standby loss a modern, well-insulated tank system suffers.

We'll leave geothermal out of the picture for now? Of course, someone 
ought to have built a mini-split Air to Water unit, but it's not out 
yet. Good luck, see you soon!

BTW: have there been 3-4 people living there, and how has the 40 gallon 
tank stood up -- any shortage of water? This will help size the next unit.

Keith

Bambi Tran wrote:
> I'm trying to figure out the energy-efficient, and life-cycle cost-effective hot water heating option for the following affordable rehab project... please advise!
> 
> -- 1000 sf rowhouse in Washington, DC
> -- 3-4 people
> -- 1 full bath, 1 half bath, laundry (washer/dryer), kitchen with dishwasher and sink... all within 20 feet of each other
> -- available utilities: gas, electric
> -- mechanical room in unfinished cellar
> -- current water heater is an old (1980s), 40 gal, gas water heater
> 
> Cheers,
> Bambi Tran
>
> 
> ---------------------------------
> How low will we go? Check out Yahoo! Messenger?s low PC-to-Phone call rates.
> _______________________________________________
> Greenbuilding email list
> List info: http://listserv.repp.org/mailman/listinfo/greenbuilding_listserv.repp.org
> List email: Greenbuilding at listserv.repp.org
> Managed by BuildingGreen, Inc. http://www.buildinggreen.com
> publisher of Environmental Building News and GreenSpec(r)
> Hosted and archived by REPP / CREST http://www.crest.org
>
>
>
>
> 

-- 
Keith Winston
Earth Sun Energy Systems
3927 Madison St.
Hyattsville, MD 20781
301-980-6325
keith at earthsunenergy.com
www.EarthSunEnergy.com

------------------------------

Message: 4
Date: Mon, 2 Oct 2006 09:14:33 -0700
From: "Reuben Deumling" <9watts at gmail.com>
Subject: Re: [Greenbuilding] Hot Water Heater options
To: "Bambi Tran" 
Cc: greenbuilding at listserv.repp.org
Message-ID:

Content-Type: text/plain; charset=ISO-8859-1; format=flowed

keep the heater you have and add heat trap/antisiphon loops to the flex
lines at the top, and where possible insulate pipes if they aren't already.
You could also add an insulation blanket to the heater.
Cost: almost negligible
Additional materials required: almost negligible
Gas use: if you're lucky, slightly lower than in past.

All other options listed by Keith (insofar as they are commercially
available technologies) are in my opinion quite spendy once you've paid
someone to install them, and, again in my opinion, the gas savings over what
you already have or can achieve with the above measures aren't going to be
all that impressive. The biggest "savings" could come from the use patterns
of hot water your occupants have or are willing to learn.

When it comes to fuel use for domestic water heating we're unfortunately
mostly guessing because it is both uncommon and a bit involved to submeter
gas/electricity and hot water use in a residence. I've done a bunch of this
on my own in households of friends and relatives who've allowed it. Anyone
else who has done this, I'd be very curious to learn of your results.

Reuben Deumling

On 10/2/06, Bambi Tran wrote:
>
> I'm trying to figure out the energy-efficient, and life-cycle
> cost-effective hot water heating option for the following affordable rehab
> project... please advise!
>
> -- 1000 sf rowhouse in Washington, DC
> -- 3-4 people
> -- 1 full bath, 1 half bath, laundry (washer/dryer), kitchen with
> dishwasher and sink... all within 20 feet of each other
> -- available utilities: gas, electric
> -- mechanical room in unfinished cellar
> -- current water heater is an old (1980s), 40 gal, gas water heater
>
> Cheers,
> Bambi Tran
>
>
> ---------------------------------
> How low will we go? Check out Yahoo! Messenger's low PC-to-Phone call
> rates.
> _______________________________________________
> Greenbuilding email list
> List info:
> http://listserv.repp.org/mailman/listinfo/greenbuilding_listserv.repp.org
> List email: Greenbuilding at listserv.repp.org
> Managed by BuildingGreen, Inc. http://www.buildinggreen.com
> publisher of Environmental Building News and GreenSpec(r)
> Hosted and archived by REPP / CREST http://www.crest.org
>

------------------------------

Message: 5
Date: Mon, 2 Oct 2006 09:58:28 -0700
From: "Mary Bull - Greenwood Earth Alliance"

Subject: Re: [Greenbuilding] ***Forest Stewardship Council: A list of
theirlatest lying certifications!***
To: "RONALD CASCIO" 
Cc: Greenbuilding 
Message-ID: <003601c6e643$fbef9e60$cd02a8c0 at Debussy>
Content-Type: text/plain; charset="iso-8859-1"

What's with you?! You should do your own local research, and share it with
your community. Being part of the big, sleek, centralized, industrial
products chain--i.e., corporate economic globalization that gobbles up
global resources--the global commons-- into its gaping maw and spits out a
seemingly endless line of products that you purchase--IS the problem.
Weaning yourself from the corporate tit is the solution. I cannot do that
for you. You have to take responsibility for that. It took me a long time to
find local resources, but the Internet and word of mouth are powerful things
and will eventually get you there.

Mary Bull, Co-director
Greenwood Earth Alliance, Save the Redwoods - Boycott the Gap Campaign
252 Frederick, San Francisco, CA 94117 http://www.gapsucks.org
Chalice Farm and Sustainable Living Center, 748 Montgomery Rd, Sebastopol CA
95472
415-731-7924 - 415-509-1188 chalicenew at earthlink.net

----- Original Message ----- 
From: "RONALD CASCIO" 
To: "Mary Bull - Greenwood Earth Alliance" ;
"Greenbuilding" ; "Tim Hermach (Native
Forest Council)" ; "Bug Deacon (Heritage Salvage)"
; "Mike (Green Frame)" 
Sent: Sunday, October 01, 2006 12:43 PM
Subject: Re: [Greenbuilding] ***Forest Stewardship Council: A list of
theirlatest lying certifications!***

> ----- Original Message ----- 
> From: Mary Bull-
>
> So-called "green" builders have to wake up from their state of denial, and
> use only salvaged wood in their buildings, such as that provided by
Heritage
> Salvage in Petaluma! (Go, Bug, go!!!)
>
> Tell ya what Mary, I would be more than happy to give you a place to stay
> here while you search out a source of recovered framing lumber available
to
> me locally that is anywhere near affordable. You can stay with us for free
> for as long as it takes.
>
> Thanks for being a part of the solution. When can I pick you up at the
> airport?
>
>
> Ron Cascio
> Chestnut Creek
> Design/Build/Consult/Develop
> Maryland`s Eastern Shore
>
>

------------------------------

_______________________________________________
Greenbuilding email list
List info: http://listserv.repp.org/mailman/listinfo/greenbuilding_listserv.repp.org
List email: Greenbuilding at listserv.repp.org
Managed by BuildingGreen, Inc. http://www.buildinggreen.com
publisher of Environmental Building News and GreenSpec(r)
Hosted and archived by REPP / CREST http://www.crest.org

End of Greenbuilding Digest, Vol 4, Issue 3
*******************************************

---------------------------------
Do you Yahoo!?
 Get on board. You're invited to try the new Yahoo! Mail.