[Greenbuilding] Sustainable Home Heating Systems (Ross MacLeod)

[Paul Eldridge]

Hi Ross,

It appears both Keith and I are sold on Fujitsu (my Friedrich is, in 
fact, a rebranded Fujitsu).  I plan to add a second unit to heat and 
cool my lower level and I'll most likely go with the 9RLQ due to its 
exceptional efficiency and superior cold weather performance.

In terms of outside appearance, the refrigeration lines for my unit are 
tucked inside a plastic channel that looks a lot like a drain spout and 
the compressor itself is hidden behind shrubbery.  It's located on an 
inside corner (jog) at the front of the house, but you'd be hard pressed 
to spot it.

As it turns out, I was recently comparing geothermal and ductless 
systems on the www.theoildrum.com and, for what it's worth, here's my 
take on the matter:

--- Begin Quote ---

Residential geoexchange heating and cooling systems are good performers 
in cold climates like my own and in applications with sizable heating 
and cooling loads or where utility rates are high. Unfortunately, as you 
can imagine, the upfront costs are often formidable ($20,000.00 to 
$25,000.00 is not uncommon) and installation of the loops can sometimes 
be a challenge; e.g., here in the Atlantic Canada many homes are built 
on relatively thin (and poorly conducting) clay soils or on bedrock.

There are other potential hurdles as well. Few homebuilders (and I 
suspect few homebuyers) will opt for such systems when electric 
baseboard or oil-fired and natural gas heating systems can be installed 
at a fraction of the cost. Locally, a number of heating oil providers 
lease new furnaces and boilers at very attractive rates simply to lock 
consumers into a long-term contracts. Homebuilders like this option 
because it doesn't tie-up their working capital. Moreover, the oil 
company assumes full responsibility for the design and installation of 
the equipment and all subsequent risk thereafter. Any cost issues aside, 
this partnership between builder and fuel provider (be it oil, natural 
gas or electric) effectively eliminates any real consumer choice in the 
new home marketplace.

Ironically, as our homes become increasingly more energy efficient, the 
economic benefits of geoexchange systems are greatly diminished. 
According to the Nova Scotia Department of Energy, the space heating 
demands of a conventional, new home in our climate is 14,500 kWh/year; 
that same home built to Canada's R2000 standards would consume less than 
9,000 kWh/year. If electricity costs $0.10 per kWh and if fuel oil 
retails for $0.85 per litre, the space heating costs of a typical new 
home fall in the range of $1,500.00/year and $900.00 for the R2000 
equivalent. Assuming the operating costs of a geoexchange heat pump are 
one-quarter that of electric resistance or oil heat, the annual cost 
savings would vary anywhere from $700.00 to $1,100.00. Additional 
savings in cooling costs, where applicable, may bump up that number by 
another $100.00 (any air conditioning savings in northern climates are 
likely to be modest due to lower cooling demands and because the 
difference in ground and air temperatures during the cooling season is 
not nearly as great as in winter, so any corresponding gains in 
operating efficiency are minimal). For new construction, the simple 
payback could be 20 years or more. For older, larger and less efficient 
homes, or where utility costs are much higher, the payback could very 
well be half that, but any way you cut it, you need a highly motivated 
customer and some measure of luck to make this proposition work.

In general, I'm far more upbeat about air source heat pumps. A standard 
air source heat pump with a HSPF of 8.5 (zones 4 and 5) produces 2.5 kWh 
of heat for every one kWh consumed. This effectively lowers the cost of 
electric heat from 10 cents per kWh in our example to just 4. A 
geoexchange heat pump with a seasonal COP of 3.5 or 4 might get that 
down to 2.5 or 3 cents, but the equipment and installation costs (or 
price of admission, if you like) could easily be two, three or four 
times higher. For most of us, conventional air source heat pumps provide 
better overall value and make for a much less complicated install.

One other thing to note. With new R410A refrigerants and high efficiency 
inverter drives, some of the better air source heat pumps now coming to 
market perform virtually at par with many ground source heat pumps 
(e.g., 20 and 21 SEER ratings and HSPF values as high as 11.0). Although 
considerably more expensive than conventional air source units, they 
still offer better returns than their ground source brethren.

--- End Quote ---

Best regards,
Paul

>Message: 5
>Date: Thu, 16 Aug 2007 11:52:48 -0400
>From: "Ross MacLeod" <drossmacleod at gmail.com>
>Subject: Re: [Greenbuilding] Sustainable Home Heating Systems:
>To: greenbuilding at listserv.repp.org
>Message-ID:
>	<74e12eed0708160852v5fa5f2b6jf1ade2a21456761f at mail.gmail.com>
>Content-Type: text/plain; charset=ISO-8859-1
>
>Keith et al,
>
>Thanks ... a lot of interesting thoughts on heat pumps.  I would love to
>learn more of any comparisons of the latest Georthermal with these mini
>split systems.
>
>Having lived in Asia for several years, I am accustomed to seeing wall units
>hanging in several rooms of a building or home, and usually they blend in
>nicely with other elements of the room.  The aspect of split systems (in
>particular multi-unit split systems) that never worked for me, from an
>aesthetic point of view, was all the outdoor plumbing and compressor units.
>that was required.
>
>When combined with a woodstove, to supply heat in the event of a power
>failure, this system could provide efficient and reliable space heating /
>cooling.   In the case of new housing construction this would eliminate the
>need for duck work and other related costs.   Does anyone have a rough idea
>of how much savings this might represent in an average 2000-2500 square foot
>2 story house?
>  
>