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How to reduce House heating cost

Discussion in 'Home Power and Microgeneration' started by Alan Combellack, May 13, 2006.

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  1. My old house id electricity heated and the power costs are beginning to
    alarm me. My bill last year was over $4000, Canadian!! I am looking at all
    the usual reduction methods including improved insulation but I would like
    to stop using electricity for heating altogether. Solar heating looks too
    expensive. I can't afford to install ducts for oil or gas central heating
    but I may be able to install hot water radiators, if such things are still
    available.
    My problem I would like help with is how to heat the water. I could use a
    gas, or perhaps oil, furnace, which would need installation of a storage
    tank somewhere.
    I understand that some people use "pellet stoves". Are these things worth
    using? Has anyone any recommendations about brands of stove to use?
    I have also heard that some are now using a separate small building which
    houses wood storage and a wood fired furnace/stove to heat water. I do have
    the space to do this but I haven't checked whether the Municipality rules
    would permit me to do this. I would appreciate any advice as to the wisdom
    of this method. At first look it may be the most economical method and
    would have the advantage that if I ever decide to build a big solar panel
    assembly it would be fairly simple to connect up and replace/augment the
    wood burner. Is wood an economical fuel to use? I have little doubt it
    would be better than mains electricity but, again, any comments would be
    gratefully received.
    Thanks in advance,
    Alan C
     
  2. Hi Alan,

    Depending upon your local climate, I might recommend a ductless heat
    pump. I live in Halifax, N.S. and our winters are generally fairly
    mild due to the moderating effects of the Atlantic Ocean. My primary
    heat source is a high efficiency oil-fired boiler and whenever
    temperatures drop below -5C, the boiler does most of the heavy
    lifting; above this temperature, the heat pump does the lion's share
    of the work.

    I opted for a small (14,000 BTU) Friedrich because it was one of the
    few models that operate at 120 volts (I'm running out of space on my
    main panel and at 120 volts, it requires just one breaker slot as
    opposed to two).

    See:
    http://server4.pictiger.com/img/264069/picture-hosting/heat-pump.php

    Between October 1st, 2005 and April 30th of this year, this little guy
    operated a total of 3,208 hours and consumed 3,946 kWh of electricity.
    In return, it provided me with 9,730 kWh of heat, thereby displacing
    1,109 litres of heating oil (@ 82 per cent boiler efficiency), for a
    net saving of $551.00. The COP works out to be 2.47 so, in effect,
    for every kWh I feed it, it gives me 2.47 kWhs of heat in return. In
    other words, instead of paying 10 cents per kWh for electric
    resistance heat, I'm really only paying 4 cents.

    This heat pump was considerably LESS expensive than a pellet stove (a
    popular alternative heat source here in Nova Scotia) and its operating
    cost is likely to be LOWER. As an added bonus, it's much cleaner and
    easier to use (a simple press of a button on a remote control turns it
    on and off); it doesn't require costly annual maintenance; I don't
    have to buy, stack and haul a tonne or more of pellets each year; and
    it will provide me with air conditioning and dehumidification in the
    summer.

    I would encourage anyone who heats their home electrically (or with
    oil) to consider a ductless heat pump as a supplemental heat source.
    I bought mine from a local distributor for $1,742.62, including tax,
    and paid an additional $400.00 for materials and labour. By
    comparison, a relatively basic Harman pellet stove, with vent kit and
    installation, retails for about $4,000, or almost double what I paid
    for this heat pump. The simple payback, based on current fuel costs,
    is under four years based on current fuel prices.

    Cheers,
    Paul
     
  3. Paul,
    Thank you very much for that excellent information. I will most certainly
    look into the system you described. A local contractor suggested we use at
    least two free standing fireplaces using "bottled" gas. These work out at
    about $3000 each and the tank adds more, no doubt. His recommendation for
    air conditioning was a separate system consisting of at least two through
    the wall air conditioners at about $2000 each so your figures look
    excellent.
    You say "ductless" so how do you get the heat/coolth to reach other rooms?
    Do you cut holes in floors; ceilings or floors and hope it moves OK or do
    you use some smallish fans to push it around?
    We live outside of Ottawa and the winters are pretty cold so I would
    probably need a somewhat bigger system than you and there is also a need for
    some other "heavy lifting" system. Even so such a system looks good at
    first look. Thanks again.
    Alan Combellack
     
  4. Per Alan Combellack:
    Whatever hardware solution you go with, don't forget clothing.

    I hesitate to suggest this - because Canadians in general probably already dress
    warmly indoors - but we wear PolarTec pants/shirts for just lounging around.
    They're soft, loose, comfortable in the extreme - and allow us to keep our
    thermostat low enough that we have to remember to turn it up when we have
    company.

    The people around here, at least, seem to have lost touch with the idea of
    dressing warmly indoors. I've seen TV interviews around the subject of how
    people's heating bills are - but the interviewees were wearing T-shirts.

    My wife (from The Old Country) used to complain about how hot it was in the
    office where we worked. Once it came out that she was wearing two or three
    layers of clothing - including long underwear - and nobody else was, the problem
    was solved.

    My introduction to the concept came when I was stopped over at Heathrow airport
    before the British converted to metric. I was freezing my pasty white butt off
    in this little airport hotel. Called the desk to tell them there was something
    wrong with the heat. Manager came up with a thermometer and sling
    psychrometer. Whirled the thing around for a few seconds, checked both
    instruments, and said - politely - "Well, sir, it *is* 55 degrees in here." i.e.
    Case closed - this room is plenty warm.
     
  5. Mary Fisher

    Mary Fisher Guest

    That's about 17C, which would be far too warm for us (In Yorkshire,
    England). Our thermostat is set to the minimum - 10C - and that's sometimes
    too much.

    I agree with the manager :) In my experiences most hotel rooms are
    overheated, ALL shops and offices are.

    When I worked for a photographer in a unit in a building of similar units
    the whole building was heated to 25C, our studio was cooled by an electrical
    'air conditioner' which was still inadequate. The boss had to pay for
    heating in his rent and cooling separately. Mad.

    I'm sitting here on a relatively cold day, there's no sun and it's raining.
    The thermometer shows 15C (59F) and I'm in shorts, T shirt and sandals. It
    will be cooler later, I'll put on a sweat shirt and, if necessary, my jeans.
    The ch certainly isn't going to be activated!

    Mary
     
  6. Hi Alan,

    You're most welcome. Oh boy, I apologize for this long post but I
    want to provide you with some background, in the hope that it may
    prove helpful.

    In the year prior to my purchase, the previous homeowners consumed a
    whopping 5,700 litres of heating oil; that works out to be $5,244.00
    per year at current prices. Through a whole series of measures, I've
    been able to reduce my home's fuel oil consumption (heat and domestic
    hot water) to less than 900 litres/year (I'll know the exact number
    when they fill up my tank later this month). That's an 85 per cent
    reduction.

    A big part of this saving was achieved by re-insulating and air
    sealing; I literally tore my entire home to the bare walls and
    reinsulated every single square inch. The attic which had only two
    inches of fibreglass (R6) now stands at R60. The walls (2 x 4
    construction) which were also R6 are now R22.

    I caulked and sealed all the exterior sheathing, inserted a half-inch
    of foam (R3) inside the wall cavity and caulked the outside edges to
    make it airtight. I then added three and half-inches of fibreglass
    insulation (R12), carefully applied a six mill polyethylene vapour
    barrier and then an additional inch and a half of foam (R7.5) on top
    of the studs. As a last step before dry walling, I taped all of the
    seems, electrical boxes, etc. with tuck tape.

    Here are some pictures of the work done in the dining room, from start
    to finish:
    http://server3.pictiger.com/img/287581/other/dining-room---caulked,-half-inch-foam-&-fibreglass.php
    http://server3.pictiger.com/img/287582/other/dining-room---fibreglass.php
    http://server3.pictiger.com/img/287583/other/dining-room---one-&-half-inch-foam.php
    http://server3.pictiger.com/img/287584/other/dining-room---re-drywall.php
    http://server3.pictiger.com/img/287585/other/dining-room---finished.php

    This is one of the side bedrooms:
    http://server3.pictiger.com/img/287586/other/bedroom---bare-wall.php
    http://server3.pictiger.com/img/287587/other/bedroom---caulked-&-half-inch-foam.php
    http://server3.pictiger.com/img/287588/other/bedroom---fibreglass-&-one-&-half-inch-foam.php
    http://server3.pictiger.com/img/287589/other/bedroom---final-taping.php

    In addition to insulating and draft proofing, I replaced all of the
    windows and doors with Pella Architectural series low-e/argon units
    and likewise revamped the old heating system.

    In addition to making our home more energy efficient, I wanted to
    ensure a diversity in energy sources in case of a disruption in supply
    (the after effects of Hurricane Juan were still fresh in our minds) or
    a radical shift in fuel costs. Thus, we have an oil-fired boiler, a
    ductless heat pump, four propane fireplaces and in-floor electric
    radiant heat; this provides us with four (mostly) independent fuel
    types, i.e., oil, propane, electric and passive solar. The boiler is
    wired to a backup generator in the event of an extended power outage
    and all of the major appliances, including the kitchen range, are
    propane. If, at some point, we build an addition on the back of our
    home, a high efficiency wood stove would be another possibility
    although, to be honest, I'm not too struck on the idea of working with
    wood.

    BTW, residential propane customers here in Nova Scotia pay $1.00 a
    litre. Although it can vary slightly according to chemical makeup, a
    litre of propane contains approximately 24,200 BTUs and at 60 per cent
    efficiency (typical of most propane fireplaces), you only net 14,520
    BTUs or 4.26 kWh/litre. With HST, that means we would pay the
    equivalent of 27 cents per kWh! Even if you were to pay half that
    cost in the Ottawa area, electric heat would still prove to be the
    cheaper option. As you might guess, we use our propane fireplaces
    only as an emergency backup and on the odd occasion when we have
    guests.

    In terms of air distribution, our heat pump air handler is located in
    the living room and faces the centre hall. This allows much of the
    heat to flow across into the dining room and to migrate upstairs to
    help heat the bedrooms. We also run our heat recovery ventilator in
    recirc mode most of the time to help distribute the heat throughout
    the rest of the home. A multi-zone ductless heat pump would be a
    better option in terms of getting the heat to where it is required.

    See:
    http://www.unitedenergy.ca/guides/fujitsu-halcyon_print.pdf
    and
    http://www.unitedenergy.ca/brochures/mitsubishi_residential.pdf

    Although this doesn't apply to you, for anyone who has an oil-fired or
    gas boiler, I highly recommend the installation of a Tekmar control.
    Our old boiler use to cycle on and off every fifteen to twenty
    minutes, day after day, just to maintain its internal set temperature;
    during the spring, summer and fall when there is no heating demand,
    this represented a huge waste of oil -- several hundreds of litres, in
    fact. With the Tekmar, the boiler never comes on unless the indirect
    hot water tank calls for heat; thus, it typically fires up once a day,
    not seventy-five or a hundred times a day. The indirect hot water tank
    stores 30 gallons of hot water and operates far more efficiently than
    either a standard coil or separate oil-fired tank and, as a bonus, you
    never have to worry about running out of hot water. We average less
    than one litre of oil per day for domestic hot water (9 kWh).

    This is our oil boiler:
    http://server4.pictiger.com/img/292877/other/heating-00.php
    http://server4.pictiger.com/img/292879/other/heating-02.php
    http://server4.pictiger.com/img/292878/other/heating-01.php

    And this is our HRV:
    http://server4.pictiger.com/img/292880/other/heating-03.php

    Again, I apologize for the long, rambling answer to your simple
    question. The key point I wish to make is that, as a first step, do
    whatever you can to reduce your heating demand (a home energy audit is
    a good place to start). Once you've done this, look at alternative or
    supplemental heat sources. For those with electric or hot water
    baseboard heat, I think a ductless heat pump is a great way to go.

    A second key point is peace of mind. If oil prices were to double
    again in the next five years, my heating costs under the "business as
    usual" or "do nothing" scenario would jump to almost $11,000.00 per
    year. Now, with these measures taken, my cost would increase from
    less than $1,000.00 to under $2,000.00. Knowing that I won't need to
    sell my home due to high energy prices allows me to sleep comfortably
    at night.

    Best regards,
    Paul
     
  7. Hi Mary,

    I use to tolerate cold very well. Like you, I could be more than
    comfortable at 15C, even 13C if dressed appropriately (above 18C and
    sweat would start to bead on my forehead). Now, since I'm on
    medication to control my high blood pressure, I'm cold at even 22 or
    23C, no matter how warmly I dress. Hard to believe this is possible
    but, sadly, it's true.

    Cheers,
    Paul
     
  8. Guest

    .... 14,000 Btu per hour?
    Where I live near Phila, 1000 Btu/ft^2 of sun falls on a south wall on
    an average 30 F January day. If 90% of that (900 Btu) enters a $1 square
    foot of Dynaglas corrugated polycarbonate glazing and the air behind it
    is 100 F, it will lose about 6h(100-30) = 420, for a net gain of 480.

    With 16'x24' ($384) of sunspace glazing, we might collect 184K Btu (54kWh)
    of heat on an average day at a rate of 184K/6h = 30.7K Btu/h with a 100-70
    = 30 F temp diff and a 30.7K/30 = 1022 cfm airflow between the living space
    and the sunspace, with a 16' height diff and a 1022/(16.6sqrt(16x30))
    = 2.8 ft^2 vent area. We might open a 2'x2' foamboard damper with a room
    temp thermostat in series with a sunspace thermostat and a $50 2 watt
    Honeywell 6161B1000 damper motor that operates for 3 minutes per day,
    consuming 2x3/60 = 0.1 Wh/day, for a COP of 54K/0.1 = 540,000.

    Nick
     
  9. Hi Nick,

    Without question, it's undersized based on the square footage of my
    home. That said, in combination with passive solar and other internal
    heat loads (i.e., lighting and appliances) it can keep my home at a
    steady temperature all the way down to about -2C; below this point,
    the boiler will fire on from time to time to help out. A larger
    capacity unit and, in particular, a multi-zone system would offer
    greater comfort and no doubt higher efficiency. But, frankly, at just
    over $2,000.00 installed, I couldn't be more pleased with what I have.

    I should add that here in Nova Scotia, day and night time temperatures
    can swing fairly significantly and even more so from one day to the
    next. Because air-source heat pumps lose efficiency as the outside
    temperature falls, I operate mine during the mildest times of the day
    -- typically between 12h00 to 18h00 -- during periods of low heat
    demand. Mid season, I let it run continuously and "bank" any excess
    heat using my home's thermal mass for use overnight and into the
    following day. By carefully monitoring the weather forecast and by
    maximizing runtime during milder periods, I can extract the greatest
    amount of operating efficiency. I'm willing to sacrifice some comfort
    in the process and thus allow the indoor temperature to rise (and
    fall) outside its normal range... now that I tolerate heat so much
    better, too much warmth hasn't been a problem. :)

    Cheers,
    Paul
     
  10. Guest

    Hi Paul,

    I asked because I wondered what happened when
    your "14,000 Btu" heat pump ran out of Btus :)

    Nick
     
  11. First of all, make SURE the house is adequately insulated and that it
    is close to air-tite. Check for leakage around doors and windows, at
    sill plates, and though the attic.
    My roughly 1500 square foot 2 story in Central Ontario costs me about
    $700 in natural gas per year for heat and hot water. It's a 33 year
    old brick veneer and aluminum siding house - put in Low E Argon filled
    vinyl windows and added about a foot of insulation in the attic.
    Running a new mid efficiency gas forced air furnace - replaced the
    original 2 years ago and saw VERY little change in gas consumption
    (butsignificant drop in hydro usage)

    *** ***
     
  12. Sorry, Nick, I was literally quoting the spec sheet verbatim, but your
    point is well taken and I'll try to be more careful in future. :)

    Cheers,
    Aul
     
  13. Mary Fisher

    Mary Fisher Guest

    Do you live in a cold area?
    Why is that?
    Ah - my first question answered :)
    I did one of those and waas told that I could save UP TO £9 a YEAR!

    I reckon we've got it sussed.

    Mary
    Yorkshire, England.
     
  14. Mary Fisher

    Mary Fisher Guest

    Yes, circumstances do alter cases.

    We installed central heating in 1984. We've never felt the need for it even
    with five children to bring up but in that year my husband had a heart
    attack and breathing in cold air - even if he felt warm - caused problems.
    He, with our youngest son (15 at the time), installed the ch which meant
    that I was uncomfortable at night but he was alive.

    Neither of us likes breathing in warm air at night now, many years later, so
    the ch remains, we've even replaced the boiler this year, but we're prudent
    enough to realise that we're getting on and that extra heating might be our
    saviour in the future.

    Medical conditions aren't the norm though and I still believe that most
    houses and public buildings in particular are overheated, at the cost of the
    Earth..

    We lit the gas fire in the dining room while having dinner tonight and it's
    still on while he's on his computer. This room is still unheated but I've
    put on the sweat shirt and jeans :)

    Mary
     
  15. SJC

    SJC Guest

    I favor both. A south facing sunroom with air heating from the low sun in winter
    from the side with an active solar thermal liquid/air collector array on the roof of
    the sunroom with heat pump. That way I can heat the home during the day with air
    heat and have the warm water with heat pump to warm the house at night.
     
  16. Hi Mary,

    To answer your question, I live in a moderately cold zone -- 4,100
    Heating Degree Days C; Ottawa, our nation's capital, clocks in at
    4,600 HDD C. However, given our maritime climate (three weather
    fronts converge over the province), temperatures can bounce up and
    down rather dramatically from one day to the next. And when
    temperatures do jump up, I run the heat pump flat out to maximize its
    performance; by the same token, on the few occasions when it falls
    below -10C, I turn it off to reduce the excess wear and tear caused by
    frequent defrost cycles (of course, any economic gain over oil is
    largely lost at this point).

    The following table shows the equivalent cost per kWh to heat my home
    with this heat pump, compared to standard electric resistance heat.
    These numbers are based on the heat pump’s monthly COP and Nova Scotia
    Power’s then domestic rate of 9.22 cents per kWh. The last number is
    the number of litres of heating oil it displaced in that month:

    October (3.2 COP) -- 2.9 cents -- 41L
    November (2.8 COP) -- 3.3 cents -- 125 L
    December (2.3 COP) -- 4.0 cents -- 217 L
    January (2.4 COP) -- 3.8 cents -- 229 L
    February (2.2 COP) -- 4.2 cents -- 191 L
    March (2.4 COP) -- 3.8 cents -- 193 L
    April (3.1 COP) -- 3.0 cents -- 114 L

    By comparison, a forty-pound bag of good quality wood pellets, i.e.,
    Shaw's Eastern Embers, retails for roughly $3.30 to $3.50. One bag
    provides approximately 80 kWh of heat (net), so the equivalent cost
    per kWh for a pellet stove is just slightly over 4 cents/kWh.

    You also asked why I wasn't terribly struck on wood heat. To be
    honest, the mess and the amount of work gives me cause to pause,
    especially as I grow older. Furthermore, there are times when it's
    difficult to get good draw and smoke can back into the room, so indoor
    air quality can take a bit of a hit. And since my heating
    requirements are now pretty modest and the heat pump is so economical
    to operate, there's no financial benefit to burning wood (it is,
    admittedly, a "nice" heat).

    Warmest regards,
    Paul
     
  17. Hi Gary,

    You do raise a valid point and this has bothered me as well. In my
    defence, I purchase "green" power from my local utility (3 blocks per
    month of 125 kWhs each). That 4,500 kWh/year more than offsets the
    3,946 kWhs of additional electrical consumption. Moreover, there are
    the sulphur, NOx and CO2 savings from not burning over 1,100 litres of
    heating oil each year.

    As a side bar to this, I'm part owner of a family business. We use to
    operate a 400 watt metal halide fixture in our main showroom
    twenty-four hours a day as a security light; with ballast, it consumed
    a total of 3,986 kWhs a year. We didn't require that much light for
    security purposes so I replaced it with a two tube T8 fluorescent
    fixture equipped with an energy saving electronic ballast; our net
    savings works out to be 3,504 kWh/year. Changing that *one* fixture
    saves us over $440.00 a year on our operating costs and just about
    offsets all of the electricity I require to operate my heat pump for
    the entire year.

    Through a number of lighting upgrades (e.g., replacing halogen display
    lighting with ceramic metal halide track heads) and other various
    efficiency improvements, I'm pleased to say I've reduced our annual
    power bill by over 65,000 kWh.

    Cheers,
    Paul
     
  18. Guest

    But heat pumps are expensive, with a very low COP, compared to some solar
    systems, and a house can store overnight heat from sunspace warm air in
    its thermal mass. Big Fins (TM) or fin-tube pipe near the top of an air
    heater inside a sunspace can collect and store higher temp heat in a tank
    for a few cloudy days and hot water for showers, with help from
    a greywater heat exchanger.

    We might store overnight heat in thermal mass under a foil-covered ceiling,
    eg a flat helix with 10'x4" PVC pipes full of water, with no water movement
    on average days and tank water flowing through the pipes on cloudy days,
    with a slow ceiling fan and a room temp thermostat to bring down warm air
    as needed.

    Nick
     
  19. Mary Fisher

    Mary Fisher Guest

    Isn't that why those of us who choose solar systems do so?

    Mary
     
  20. Mary Fisher

    Mary Fisher Guest

    Hello Paul,
    I don't understand that ... those units aren't used here ...
    It's like that here in Yorkshire too!
    Those figures are impressive, I think, but what's a COP? I'm sorry to seem
    so ignorant but your systems are different from ours. I'd still like to know
    though.
    Ah! That's why we're not keen. I remember the filth of coal fires. For a
    time we had a wood fired stove which was many years ago and inefficient but
    there was still wood to cut (and keep us warm in the process) and store and
    even modest amounts of ash to clear. As we age and get rickety that sort of
    activity and experience isn't good for us.

    It's just that I thought you had lots of timber which could be exploited,
    that timber was the first choice for everything ... I know so little (but
    would like to know more).

    I know someone with a lovely big automated pellet feed stove. It looks good
    and is (far too) efficient at heating the room. But to keep the door bright
    the wife has to clean it every morning. Ash has to be cleared every day.
    Pellets have to be stored (they have plenty of space for that, we haven't)
    and either collected or delivered (producing carbon emissions).

    While these tasks aren't onerous in themselves I do wonder how my friends
    will cope if they become arthritic and can't open the stove door easily or
    bend down to clean it or ... well, I'm sure you understand.

    Some friends took me to their large century old log cabin in northern
    Washington State. That was delightful, an enormous hearth burned huge logs
    and there were no problems about smokeless legislation, as there is here.
    But the logistics of that system on aging folk makes it difficult too.
    Perhaps we're all living too long ...
    Oh - I haven't experienced that since I was ten years old ... when I lived
    in a mid C19th back to back terrace house. That's when everyone had coal
    fires (inadequate to boot) and the air was filthy. I didn't like marguerites
    (the large white daisies) because of the black spots on them. I didn't
    realise that the black spots were soot.
    Ours too. Since we insulated the house we rarely use any heat. Good, innit!

    That's another problem with solid fuel room heating though, you can't turn
    it off when you're sweating.
    If we were building from scratch I think we'd use that system but it would
    be financially impossible now - and probably wouldn't even be allowed. We
    have to compromise :-(
    and to you :)

    Mary
     
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