Skip to comments.Any HVAC Folks Out There? (Vanity?
Posted on 11/07/2010 4:26:48 PM PST by plinyelder
This was a tough one to figure out what category this should go in!
Well .. Anyway .. I need some advice from an expert on electrical use.
Been out of work for over two years now and I am 'squeezing' every dime to survive!
Here is my question: I live in a two story, vinyl sided home.
I have an electric fireplace downstairs (12.5 amps +120 volts= 1500 watts) and the same upstairs.
I also have .. what I think is a 2.5 ton 'Heat Pump'.
I have No Clue, (being from Florida) What or how a heat pump works so .. Would it be 'cheaper' to run the two fireplaces to heat the home, (heat pump off) or should I just use the heat pump?
The fireplace upstairs is in the master bedroom and Really does the job but the one downstairs, really only warms two of the four rooms on the lower level.
I think that electric runs between 11 and 13 cents per Kilowatt hour.
Oh yea .. Both fireplaces can be set to turn off and on as needed (thermostat?) but the one on the lower floor has to run on high .. all the time to do the job.
As long as you keep the heating strips from turning on in the heat pump, it is the most cost effective. Usually, there is a little indicator on the thermostat to tell you when the heat strips turn on. The only way to keep them off on some units is to keep the inside temp setting low enough to keep the chill off in really cold conditions.
Heat pump, it’s an air conditioner that will take heat from the outside air and when the outside gets cold enough will automatically switch to electric resistance heat.
This assumes properly sized and operating equipment.
Put some socks and another shirt on.
I also live in Florida. Shorts and a t-shirt aren’t meant to be worn ALL the time ya know.
Once temperatures start to go below about 27 degrees heat pumps are no more efficient than resistance heat (your electric units).
The heat pump is, by far, the most efficient. Electricity runs the compressor but extra heat is achieved by changing a gas to a liquid, and vice versa at the expansion valve. It turns your house into a giant refrigerator, giving you the ability to reverse the location of the condenser and the evaporator, depending upon the season. Fireplaces, especially those that don’t use outside air for combustion, will actually cool your home except for the area right in front of the flame.
Oh, yeah... Also, fireplaces suck more heat out of the house than they add. Install an insert or wood stove and it will heat well without sucking all of the warm air up the chimney.
I probably wasn't very clear on Where I live.
I am originally from Floor-E-Duh but live in Virginia now.
(That's why I know nothing about heat-pumps .. They seem to be very Inefficient?)
Our home is heated and cooled by a closed-loop geothermal system. The system works great until the temp drops substantially below zero F. The home is earth sheltered with ICF construction so heat loss is less of an issue than most.
We have a wood stove and a electric central heating and air conditioning system, plus some little electric space heaters (some ceramic), and one big electric fake “fireplace”. The electric fake “fireplace” had to be abandoned because it just ate electricity prohibitively. It’s cute, but not practical. - We close the doors to the upstairs rooms, leaving them cracked just enough in the bathroom at the head of the stairs especially to keep the pipes from freezing. We use the woodstove as an adjunct to the central system, which we keep set on about 66 with the woodstove running on slow burning wood most of the time. Along with the central system set at 66, it never gets really cold in the house - AND the woodstove keeps the floor above it warm and toasty in that bedroom where husband does some limited work. The little space heaters we use in a very limited way, exercising safety precautions with them; the wood stove, too, being careful to use soot removing logs and sweeping the pipes with a wire chimney sweeper. Even if we have to buy a bit of firewood one day, it’s still good auxiliary heat and dependable if we should have a power outage (which we have had lasting days in the past). - We also wear enough clothes in the house that we don’t feel like we have to jack the temp setting up to try to be like Florida in order to be comfortable. I think we sleep better at night if it is not ramped up on high heat or the woodstove ripping and tearing. - Getting up and keeping the circulation working in the body is also a good thing. Our electric bill, including everything else, has always been very reasonable.
The heat pump, being a reverse refrigeration cycle, is more efficient in normal temperatures.
Problem is that a heat pump doesn’t work well (if at all) in extremely cold weather. At low temperatures, the heat is supplied by an electric resistance strip.
Why would that be since you are extracting heat from in-ground water at roughly 55 degrees, year-round? I would think that the efficiency would be consistent no matter what the air temperature (since it doesn't use outdoor air as the heat exchange medium). I obviously don't understand something about geothermal.
Heat pumps don’t work when the outside temp is below 40 degrees.
You’re better off keeping the lower floors warmer imo as heat rises and will eventually make its way upstairs. I would suggest keeping the T-stats low but not off, keep them at 60F if need be but if you go from freezing to 72F you’re just defeating any savings.
If you have electric hot water don’t forget to turn down both elements (if you have two) to about 130F - they run 24 x 7 and can really eat into your bill. Shower with a friend.
If your COP Coefficient of Performance is 10 it means that the heat pump puts out 10 Kw for each Kw put in. Check out the specs of your heat pump first. If is is an old unit it may be much less.
Well .. I have worked for over fifty years for what little I am trying to hang onto.
Oh, and yeah, we also use room-darkening, insulated pull-down shades over our miniblinds, especially at night. Any time we can pull back curtains, shades or blinds and allow the sun to shine in and heat the rooms, we do. - I’m no expert, as you can tell I’m sure - but, we do live cheap and not spoiled to ipsy pipsy comfort. - Oh, and when I use the electric oven, I don’t waste the heat from that when I turn it off, I open the oven door a bit to allow that heat to join in the party. We also use light bulbs to heat up and dogs’ houses outside and a small space heater set on very low to heat up the cat room which is also furnished with a very padded enclosed cat bed. Having hairy pets is also helpful. One dog has a very heavy winter coat, while the one which does not has to be sort of coddled. The cat has a Persian daddy and a very full long coat winter and summer. - We also keep a bit of firewood inside so that we don’t have to run in and out. The doors are kept pretty much shut, but it is important to allow enough fresh air to keep from getting carbon monoxide built up. (We also have a carbon monoxide alarm; which came in handy the one time it went off due to the woodstove door being a bit ajar. That one time did two things, it made the alarm cost well worth the fifty or so dollars we paid for it, and it made us become very aware of shutting the stove door good every time we put wood in it.
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