[Greenbuilding] Nyle Geyser HPWH - Preliminary Results (was HEAT PUMP WATER HEATER)

[Paul Eldridge]

I installed our new Nyle Geyser heat pump water heater earlier today 
(http://www.nyle.com/water-heating/geyser-r/) and I'm pleased to report 
that the results are even better than I had anticipated.  It took 1.64 
kWh to bring 115 litres of water from 16.7°C to 49°C, with a maximum 
draw of 672-watts (average ambient air temperature: 17°C, relative 
humidity: 58%, and total runtime: 2 hours and 57 minutes). It's not as 
loud as our dehumidifier and it operates at a slightly lower pitch, 
which I find generally less irritating.

If we had an electric water heater as opposed to a side arm the numbers 
would have been presumably a little better, because some of the heat 
supplied is inevitably syphoned-off by the feed and return lines that 
connect the tank to our oil-fired boiler. All in all, not too shabby 
given that it would have taken 4.3 kWh to do the same job using electric 
resistance.

I ran two loads of laundry back-to-back in our Bosch front loader, both 
in warm water.  The first load, plus a couple hours of standby tank 
losses came to 0.42 kWh, and I know from past experience that a similar 
size load with our small electric water heater would have consumed in 
the order of 0.90 to 0.95 kWh.  Our second load of laundry used just 
0.29 kWh, which I find particularly impressive.

I noticed that the Nyle consumes just 1-watt in standby mode (it has a 
temperature probe that continually monitors the temperature of the tank 
so that it knows when to turn itself back on); that's welcome news. I've 
plugged ours into a simple mechanical timer that has a twenty-four 
push-pull pin wheel, so it's not scheduled to come back on until 06h00, 
at which point it's free to run for up to two hours before the timer 
kills the power again; if need be, we'll add a second cycle for the 
evening, but I expect that once per day will suffice.

This is a solidly built and well engineered product and I think it's a 
great option for anyone who currently heats their DHW with either oil or 
electricity.

Cheers,
Paul


--- Original post ---

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