We had our house built by a "budget" builder. The exterior walls are mostly plastic (styrofoam panels) with wood in the high strength areas (corners). All very flammable.
If I were to build some type of auxiliary heat, the combustion system would be located well away from the house. There is a guy about a mile down the road from me who has a cube shaped steel box about 6 feet on a side with a chimney sticking out of the top. It sits away from his house and barn but is always smoking in the winter. I need to stop in and see what it's doing. It could be heat for his barn since he has cattle and chickens....lots of chickens, fresh dead ones on the road every few days.
First upgrades will be insulation in the basement. That's where my lab is and spend quite a bit of time here. I keep one end of it heated to somewhere in the mid to high 50's. I'm sure a lot of that heat is wasted through the concrete block walls.
The heat pump and controller are what the builder provided, which is again budget stuff, probably the minimum EER. The controller does seem to have some intelligence. It will engage the heat pump first under normal operation and then turn on the electric heat if the inside temp doesn't drop after trying heat pump only for a while. When the heat pump goes into defrost mode every 5 minutes, it also turns on the electric heat. This can happen even if the outside temp is in the low 40's and it's raining.
When my wife isn't home I keep the house at 63 degrees or less. When she gets home I turn it up to 68 for a while, then 65 overnight. I have learned to raise the thermostat in 1 degree increments. A quick change in setting will bring out the coat hanger!
We had insulation installed in the walls between the garage and the house, but there is no heat in the garage. The water that dripped from the snowblower due to engine heat is still frozen on the garage floor. My wife won't go in there. The cars are kept outside.
I like this idea. Not sure about the wiring though. Here is a picture of my thermostat. The resistive heat element turns on automatically. Is it possible that it is controlled by one of the mercury switches?
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I have a bypass switch for my emergency heat strip, so I can force the heat pump to run by itself. I keep the EHS off except when the outside temp is below 12F.Above that temp, the 15.8 SEER heat pump is supposed to be above 1:1 on efficiency. (1:1 is the point where the energy consumption of the heat pump is equal to the heat capacity for pumping heat.)
I think Fujitsu claims they have one that doesn't go below 1:1 until it gets below 0F.
I have a NEST thermostat, and have the temperature programmed with slow increases from 7 in the morning until around 1pm (66F), then hold until around 8pm and gradually start back down again at night (to 62F).
I don't mess with the thermostat.
I think Fujitsu claims they have one that doesn't go below 1:1 until it gets below 0F.
I have a NEST thermostat, and have the temperature programmed with slow increases from 7 in the morning until around 1pm (66F), then hold until around 8pm and gradually start back down again at night (to 62F).
I don't mess with the thermostat.
RIPCORD....
the thermostat is held on with 6 captive screws located thru holes around the bulbs and pivot.
Loosen the screws and the thermostat will seperate from the subbase. the heat strips will be controlled from the lower bulb through the w2 terminal on the subbase if i remember correctly. that t-stat is at least 15 years old.
Note :
the strip heat is staged in behind the heat pump by 1.5 to 2 degrees.
Tubelab: If your heat pump is defrosting every 5 minutes it is broke. Small control board in outside unit may have jumpers or dip switches to adjust the defrost interval. Also improper freon charge will play havoc. Cycling on pressure switches will some times seem like defrost mode.
the thermostat is held on with 6 captive screws located thru holes around the bulbs and pivot.
Loosen the screws and the thermostat will seperate from the subbase. the heat strips will be controlled from the lower bulb through the w2 terminal on the subbase if i remember correctly. that t-stat is at least 15 years old.
Note :
the strip heat is staged in behind the heat pump by 1.5 to 2 degrees.
Tubelab: If your heat pump is defrosting every 5 minutes it is broke. Small control board in outside unit may have jumpers or dip switches to adjust the defrost interval. Also improper freon charge will play havoc. Cycling on pressure switches will some times seem like defrost mode.
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We have natural gas and a moderately well insulated antique house, and last month we had a $500 gas bill. It was a rather cold month even for January. We have a modern "high efficiency" steam boiler, and steam heat is not particularly efficient, this boiler has an AFUE of about 84% which is about as good as you can do without superheating which is only available in larger boilers. There is no energy star option.. It does keep us comfortable for the most part.
My parents have lived with heat pumps since the early 1980s and used supplemental heaters scattered around the house to avoid resistive heat. The concern I think with running the heat pump at low temperatures is you are not getting a lot of heat and while the cost relative to resistive heat might be attractive in the short term I wonder what the effect is on compressor service life - i.e. if it shortens the life of the compressor by several years the savings may be negated by early replacement.
My parents have lived with heat pumps since the early 1980s and used supplemental heaters scattered around the house to avoid resistive heat. The concern I think with running the heat pump at low temperatures is you are not getting a lot of heat and while the cost relative to resistive heat might be attractive in the short term I wonder what the effect is on compressor service life - i.e. if it shortens the life of the compressor by several years the savings may be negated by early replacement.
Figure above is electricity at ~$0.10-0.12 per kW-hr, as it is here.
Looks like cost for propane is close to electricity, as it is ~$2.6 per gallon and a gallon is 1/1.09 therms - so roughly $3 per therm, but variable.
I have a drafty 59 year old house with not a lot of insulation, my bill for heating and electricity combined is (in Minnesota) ~$180-200 in the worst months. 96% Natural gas forced air furnace. Temp setpoint 68 when home, 60 when not.
There is no free lunch.
Electric heat is 100% efficient. (Minus much of what you lose in leaky poor-insulation ducts in attic/cellar.)
Heat-pumps *exceed* "100% efficiency". They pump heat uphill. To a point, an electric freon machine can pump-up more heat energy than the electric it sucks. (Still no free lunch: you are making the outside colder.) But there is a limit, where efficiency drops below 100%, and electric would as good and less mechanical wear/tear. Sadly this limit does not cover your coldest days/month. The heat-pump company in Maine went out of business, possibly because he over-sold the benefits and the poor pumps died trying to cover January.
But we do NOT really (individually) care about "efficiency"! As you say, it is COST. George could move up in the hills and get scrap coal for free. It may not burn well, he may not get 20% of the potential heat in the coal, but FREE! I just cut 20 large trees, more wood than I know what to do with, I could build a bonfire in the yard and capture 1% of the "free" heat through my windows. (But just bucking-up big trees is real work and expense.)
Above "a cold day in the northern US", a heat-pump can run over 100% efficient, but on expensive electricity. For long periods of spring and fall, it is the cheapest to run (unless you can find free or very-cheap fuel).
Coal is cheap per ton in large quantities. The burner is expensive, labor-intensive, not efficient in small sizes, the smoke and ash are dirty. Coal was THE fuel until over-exploited coal miners tried to upset the economics and basically pushed all small burners to oil fuel (car fuel byproduct).
In much of the US, pipe-gas is cheap per BTU and the burner is inexpensive. If available, this is usually your Best Deal.
For small occasional heat where pipe-gas is not at your house, electricity does OK. Especially because past policy has left some very low electric rates in pockets of the country (TVA, Oregon).
For larger loads, Fuel Oil and Propane compete. They both come on a truck so are available almost everywhere. Propane looks cheaper per gallon (most winters) but has only 2/3rd the BTU per gallon of Oil. Oil smoke has sulphuric acid so is not worked to high efficiency (exhaust temp well over 212F, leaving much heat un-caught); Propane is generally cleaner and my heat exchanger exhausts at 110F (drippy) and just warm enough to warm the house. I believe a 95% propane burner equals +/-10% a "85%" oil burner on cost, depending on market. (And I'm in an Oil market, my best propane price is high.) 80% gas burners are also available a bit cheaper, and seem to make sense in Texas and other places where gas is cheap or loads are not-large.
> disconnecting it ...
There's a big wire going to that coil. Find a switch or disconnect a wire. (Do not get killed or burn down the house!!) Your heat pump will moan and moan. It may be able to pump-up some more than it does. (However that thermostat suggests it is already getting cold in the house, heatpump maxxed-out, by the time the coil is cut in.)
Your next step would be to replace the electric coil with a fuel burner. Electricity is much "too good" to use for heat; it's just easy/convenient. Coal oil gas etc give much more BTU per $. Just as before, you run the heat-pump until it can't keep-up, cover the difference with fuel. However that coil is maybe $50. If you could buy a fuel furnace without the house-fan it would be $500+; over $1000 installed for gas, $2000 for oil. Are your heating costs that bad? (Yes, they sure can be; you may have been over-sold on that heat-pump.)
No, that's wrong. It's very efficient, it converts 100% of the power into heat.
It's just not cheap. Edit: dang, someone already said that
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It seems to me that George's suggested is the best; a small auto four cycle gasoline engine set for propane. You could arrange a heat exchanger to put heat INTO the returning water before it reenters the engine (to minimise cylinder wall wear), and then pass the hot water (typically 180F) to the home for passing through conventional passive radiators. About 70% of the gas energy is absorbed in the water jacket and the exhaust so some fairly careful plumbing design might need an additional pump; the gas engine has a pulley so a large alternator could be run too to charge accumulators and assist with water circulation. You could not need to drive anything from the rear of the motor.
An engine that might work well is the B210 1166cc OHV L4 from Nissan. They are very simple, very cheap in junkyards, quiet, efficient, and easy to set up for propane. They do around 69bhp on gas, so on propane would be about 60bhp and should be run at around 20bhp on a large alternator for about 60bhp equivalent of low grade heat from the water jacket.
HD
An engine that might work well is the B210 1166cc OHV L4 from Nissan. They are very simple, very cheap in junkyards, quiet, efficient, and easy to set up for propane. They do around 69bhp on gas, so on propane would be about 60bhp and should be run at around 20bhp on a large alternator for about 60bhp equivalent of low grade heat from the water jacket.
HD
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The Honda Exlink has been available here for more than 10 yrs, unfortunately with steam heat it is none starter for me, but National Grid offered a pretty big incentive for those willing to make the conversion to forced hot water heat.. Something you only do if you want to rip your house apart in the process. (After a fire or during a major non resident reno where interior walls and floors are opened up)
Honda Worldwide | Power Products - Household Gas Engine Cogeneration Unit
Honda Worldwide | Power Products - Household Gas Engine Cogeneration Unit
Being a past electric utility employee, I marvel at the many way people try to justify interesting new technology for heating. 100% efficient electric heating, not from source to usage I'm afraid. Nothing is! Less conversion and transport effects efficiency. If you are taking about lowest cost at this time, natual gas burning at the heating point is most cost effective in my experience, period. Good luck.
It only does that if its cold and being rained on. I went outside and watched it last wednesday. It went into defrost mode, because it was starting to ice up. If the outside temp is say 30 degrees and it's raining, that rain is just looking for an excuse to turn to ice. A metal box that's below ambient and sucking in that cold rain is just the ticket. Wednesday the temperature stayed between 28 and 30 degrees F and it rained a fine mist blown by 15 to 25 MPH winds all day long. That was better than the 3 to 7 inches of snow that was predicted. It was however the day that the heat pump kept defrosting a lot.....when it ran. The electric heat kicked in when the defrost cycle got short.
Defrost mode is essentially air conditioner mode without the outside fan spinning. You are borrowing some of the heat you just pumped into the house and sending it back outside to warm the coils enough to thaw them, then the outside fan kicks on blowing a cloud of slushy water out of the unit......don't be standing next to the unit when this happens. I learned that last Wednesday.
Today it was in the low to mid 20's for most of the morning with zero wind. I was indeed outside working in flip flops and jeans, no shirt for several hours and I didn't get cold. Wednesday, was NOT a shirtless day.
I don't know how accurate these Fitbit things are, but so far today I have burned over 4,200 calories. My average on a warmer day is 3000 to 3500. The heat escaping from my uninsulated body needs to come from somewhere.
A Tough Mudder outdoor obstacle course race that covered 10 miles and 21 obstacles in 40 degree weather with one of the obstacles involving being dropped into muddy ice water and swimming under a barrier was the only 5000+ calorie day I have seen.
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"Defrost mode is essentially air conditioner mode without the outside fan spinning. You are borrowing some of the heat you just pumped into the house and sending it back outside to warm the coils enough to thaw them, then the outside fan kicks on blowing a cloud of slushy water out of the unit......don't be standing next to the unit when this happens. I learned that last Wednesday."
your heat pump has a clock in it that starts after defrost and will allow the unit to run in a frozen state for a set amount of time (usually 30-60-90 minutes before it will allow defrost. system will defrost till the outdoor coil reaches 60-70 degrees or a limit of 10 minutes. Small sensor on the outdoor (thermostat or thermistor) initiates and terminates the timer, Outdoor thermostats can be used to limit the amount of strip heat used.
your heat pump has a clock in it that starts after defrost and will allow the unit to run in a frozen state for a set amount of time (usually 30-60-90 minutes before it will allow defrost. system will defrost till the outdoor coil reaches 60-70 degrees or a limit of 10 minutes. Small sensor on the outdoor (thermostat or thermistor) initiates and terminates the timer, Outdoor thermostats can be used to limit the amount of strip heat used.
Speak of the devil.
Not strictly heat pump related but more water heater related. Our off-peak hot water heater is leaking from the top of the tank and its a fairly steady stream of water though nothing to be seriously concerned about just right now. But I am concerned about there being damage to the wood wall which is right up next to it that sits on the same level cement slab as the hot water does. So I'm going to have to figure something out quick so I can shut the water flow off and remove the breaker for the heater.
So I'm off to find a hot water heater in the same size to replace it. Budget is very tight right now though so we might end up having to buy a camping hot water heater to use for the time being while we save up for a replacement.
$129 seems to be the cheapest LPG tank camping hot water heater that I can find on eBay.
Not strictly heat pump related but more water heater related. Our off-peak hot water heater is leaking from the top of the tank and its a fairly steady stream of water though nothing to be seriously concerned about just right now. But I am concerned about there being damage to the wood wall which is right up next to it that sits on the same level cement slab as the hot water does. So I'm going to have to figure something out quick so I can shut the water flow off and remove the breaker for the heater.
So I'm off to find a hot water heater in the same size to replace it. Budget is very tight right now though so we might end up having to buy a camping hot water heater to use for the time being while we save up for a replacement.
$129 seems to be the cheapest LPG tank camping hot water heater that I can find on eBay.
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