[Greenbuilding] HEAT PUMP WATER HEATER

[John Salmen]

Hi Paul
I am very curious to hear how it turns out and glad to hear that Nyle is
still producing the units. I had one set up for installation in a house a
couple of years ago with a small duct system for venting - owner didn't go
with it unfortunately.

I have one drawn in for a current project but again the owner is reluctant.
Feedback from a user would be useful.

Best
John

JOHN SALMEN ENVIRONMENTAL DESIGN
4465 UPHILL RD, DUNCAN BC V9L 6M7 PH 250-748-7672 FAX 250-748-7612

 

-----Original Message-----
From: Greenbuilding [mailto:greenbuilding-bounces at lists.bioenergylists.org]
On Behalf Of Paul Eldridge
Sent: October-11-12 7:14 AM
To: greenbuilding at lists.bioenergylists.org
Subject: Re: [Greenbuilding] HEAT PUMP WATER HEATER

Hi Alan,

I just purchased a Nyle heat pump add-on to supply heat to the side arm
attached to our oil-fired boiler.  It's a 115-volt system that draws a
maximum of 800-watts and has a rated heating capacity in the order of
1.8 kW (6,275 BTU/hr). This one can be used with an electric, solar, gas,
oil-fired or indirect water heater (the Geyser RO) but there is another
version designed specifically for electric tanks (the Geyser R).

See: http://i362.photobucket.com/albums/oo69/HereinHalifax/Img_1914.jpg

The cost of the Geyser RO is not unreasonable at $1,150.00 CDN (the
electric-only R model is cheaper).  Installation is pretty straight forward
and you don't have to discard your existing tank or modify your plumbing.
The fact that it works in conjunction with your existing water heater also
eliminates the risk of hot water run outs or sub-par performance in the
sense that if your electric or oil-fired water heater can keep up with your
DHW demands today, it will be no different tomorrow or the day after, except
that the Nyle will presumably take over the lion's share of the work.

Another nice thing for us is that the Nyle will supply us with all the DHW
that we require (at about one half the cost of a conventional electric water
heater) *and* it will provide us with "free" 
dehumidification.  As it stands now, I run our dehumidifier eight months of
the year, seemingly non-stop some days, and so this responsibility will be
handed over to the Nyle, in whole or in part (the outdoor relative humidity
as I type this is 100 per cent); in effect, we'll receive two services for
the price of one.  In addition, we'll have the added benefit of free coolth
during the summer.  But what about the winter months you ask?  I'm not
overly concerned.  Our home is heated by two high efficiency ductless heat
pumps that supply us, on average, two and a half to three kWh of heat for
every kWh they consume.  The Nyle will "steal" some of this heat to heat our
DHW, but we're still way ahead in that the heat we sacrifice will have been
provided to us at as little as one-third the cost of electric resistance.

At the moment, our DHW is supplied by a small 70-litre 115-volt/1.38 kW
electric tank that was originally intended to pre-heat the water feed to our
side arm.  We wanted to minimize the amount of oil that we consumed for hot
water purposes and the electric tank did cut the runtime of our boiler by
roughly two-thirds.  Then, rather than let the side arm call for heat at
will, we decided to limit the boiler's operation to a single ten minute run
twice a week, and eventually cut that to once a week. 
Ultimately, we decided to stop using the boiler altogether, which means that
we have to pull enough hot water through the system to offset the standby
losses of this larger second tank. Consequently, we take somewhat longer
showers than we would otherwise, wash our clothes in hot water and
occasionally open up a hot water tap for no good reason; if we don't, the
supply temperature falls off rapidly and we experience cold showers. Since
we'll be using the heat pump to heat the water stored in the side arm, we
can now remove the electric tank from service and eliminate this needless
usage.

Presently, we use an average of 4.0 to 5.0 kWh a day for DHW purposes and I
anticipate that our new Nyle will cut that by more than half -- not a huge
savings by any means, but still worthwhile from our perspective.  First of
all, we'll eliminate the standby losses of the electric tank which at
47-watts works out to be just over 1.0 kWh a day.  Secondly, we'll no longer
need to wash our clothes in hot water and can eliminate the other steps we
take to prevent the side arm from cooling off.  The additional heating
demand during the winter months -- perhaps 3.0 kWh per day which translates
to 1.0 or 1.2 kWh actual with respect to our two ductless heat pumps -- will
be offset in large part by the reduction in runtime of our dehumidifier come
spring, summer and fall.

I'll have power monitors installed on our Nyle and our two ductless heat
pumps and will log this data in a spreadsheet so that I know precisely how
much electricity is consumed by these three appliances on a day by day and
hour by hour basis.  I'll provide the list with occasional updates once I
get the unit up and running.

Cheers,
Paul

>
>Alan Abrams alan at abramsdesignbuild.com wrote:
>
>need help quantifying the (presumed) benefit of using a heat pump water 
>heater for a new, airtight house, passive house insulation and glazing.
>There is no natural gas serving the site.
>
>the cooling load is very low--the house is surrounded by tall trees--but it
>will have a Wash DC latent load.   The trees compromise the potential of
>solar thermal...
>
>...so the question is, does the efficiency and modest dehumidification 
>capacity of a HP WH offset the extra heat load, compared to either a 
>straight elec resistance WH, or bringing in propane service?
>
>-a


Alan Abrams*


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