Save $$$ - Heat with Wood

[jk96]

I have geo thermal and so far its been maintance free, other than filters. Lets hope that keeps up. Its really expensive but when we had ours installed there were a lot of tax credits. We also pay less for the electricity for the geo thermal.

We are only 4 years in our ours. Had a board go out under warranty in year 1. No other issues since. I bought the washable filters for ours due to the cost of disposable ones.

 

[LD1]

Not really any more maintenance in a Geo unit than with just a stand alone AC unit.

And if you have a wood furnace, hooked to ductwork, you still have filters and temp control wiring and all that.

Nothing is maintenance free, and nothing lasts forever. They all require upkeep and periodic maintenance/inspection.

 

[s219]

Our geo has worked great, but with a couple minor glitches. One time it cutoff in really cold weather because the aux heater wasn't wired up properly and the long run times of the main unit dropped the ground loop temperature below freezing. The HVAC guy came out and properly hooked up the aux heater (which now only runs for minutes at a time in really cold weather, to act as a boost) and clipped a jumper on the main board to allow sub-freezing ground loop temperatures. That shouldn't normally happen now that the aux heater is working, but we're running a water-methanol mix so it doesn't matter either way.

Second glitch was this past summer, on a hot humid night the AC cutoff while we were asleep and we woke up about 1am sweating. Turns out that a small section of cold pipe from a coil had no insulation on an elbow, and was sweating inside the cabinet. The sweat had been dripping on the main control board and eventually corroded out some of the circuits. When I discovered that by flashlight early in the morning I was both relieved to make such an easy visual diagnosis (the SOB machine sabotaged itself) and annoyed something so simple as missing insulation could take the unit out of commission. Luckily the tech was out the next day and had a spare board on his van, and also fixed the insulation. I think the guy was impressed I was able to diagnose the problem, but I told him it was so obvious even a smarty-pants mechanical engineer like me could figure it out. Like I said, the dumb machine sabotaged itself.

Other than those glitches, the system is a quiet powerhouse and cheap to operate. I love not having an outside fan unit making noise, and there's no question the ground loop (which uses four ~ 120' wells) is a much better way to exchange heat with the environment than a fan working against ambient air. I never really liked the idea of heat pumps for heating, but with a ground loop it's almost like an infinite reservoir to exchange heat with and really packs a punch.

 

[4570Man]

How does the geothermal work when heating. The cooling seems pretty straightforward but I haven't figured out the heating part.

 

[LD1]

How does the geothermal work when heating. The cooling seems pretty straightforward but I haven't figured out the heating part.

If you don't understand how the heat works, you probably don't understand correctly how the cooling works.

Its not as simple as circulating ground water through it and using that cool water to cool the house, if that's what you were thinking.

There is refrigerant just the same as an air to air heat pump, or your fridge and freezer.

Operates off the same principal.

But rather than use a variable outdoor air temp for the medium to heat/cool the refrigerant.....it uses ground water.

So basically....when heating.....your compressor compresses freon.....which makes it get hot.....let's say 150 degrees but it started out at 50. So it gained 100 degrees by compressing it.

Now we circulate that through the furnace and blow air over it, this air is warmed and heats your house. Cooks the freon down to say 100 degrees. But remember it's still compressed.

So when we uncompress we have to loose that 100 degrees. So now the freon in zero.

Up to this point, a convention air to air, and Geo are the same.

On a Geo, from this point, we use 50 degree ground water to warm the freon back up to 50, and start all over. This cools the water... Which circulates back through thousands of feet of pipe in the ground, to warm it back up.

On an air to air....that 0 degree freon circulates through the outdoor unit, and blows outside air across it to warm that zero degree freon back to whatever the outside temp is. Which is why the colder it is outside, the less efficient an air to air is. Where as Geo efficiency remains as constant as the ground temp is at the 6' depth the loops are burried.

Air conditioning is just the opposite. Compressor still compresses and heats freon. But is either cooled by the outside air on an air to air, or cooled by the ground water first. Then when uncompressed and super cooled, it's circulated through the heat exchanger that the fan blows across, blowing cold air out your vents

 

[LD1]

How does the geothermal work when heating. The cooling seems pretty straightforward but I haven't figured out the heating part.

If you don't understand how the heat works, you probably don't understand correctly how the cooling works.

Its not as simple as circulating ground water through it and using that cool water to cool the house, if that's what you were thinking.

There is refrigerant just the same as an air to air heat pump, or your fridge and freezer.

Operates off the same principal.

But rather than use a variable outdoor air temp for the medium to heat/cool the refrigerant.....it uses ground water.

So basically....when heating.....your compressor compresses freon.....which makes it get hot.....let's say 150 degrees but it started out at 50. So it gained 100 degrees by compressing it.

Now we circulate that through the furnace and blow air over it, this air is warmed and heats your house. Cooks the freon down to say 100 degrees. But remember it's still compressed.

So when we uncompress we have to loose that 100 degrees. So now the freon in zero.

Up to this point, a convention air to air, and Geo are the same.

On a Geo, from this point, we use 50 degree ground water to warm the freon back up to 50, and start all over. This cools the water... Which circulates back through thousands of feet of pipe in the ground, to warm it back up.

On an air to air....that 0 degree freon circulates through the outdoor unit, and blows outside air across it to warm that zero degree freon back to whatever the outside temp is. Which is why the colder it is outside, the less efficient an air to air is. Where as Geo efficiency remains as constant as the ground temp is at the 6' depth the loops are burried.

Air conditioning is just the opposite. Compressor still compresses and heats freon. But is either cooled by the outside air on an air to air, or cooled by the ground water first. Then when uncompressed and super cooled, it's circulated through the heat exchanger that the fan blows across, blowing cold air out your vents

 

[deezler]

I'm gonna chime in here, just cause I can.

I heat this house entirely with wood:

https://lh3.googleusercontent.com/-...8aKpSSTIQE/s640/blogger-image--1774268058.jpg

In the two southeast Michigan winters since finishing the house, we've used 5-6 face cords (less than two full cords) per year. That's it.

My dad gave me his old chainsaw, which has needed nothing. He also lets me borrow his gas splitter.
I already had a nice tractor to develop and landscape the property, obviously.
I enjoy spending time cutting and splitting wood. So do my buddies - I give away a lot of firewood.
The woodstove (Napoleon 1450) and chimney pipe was under $2k total, easily folded into the construction costs.

I did buy a chimney sweep kit off amazon, so I guess you could say that wood heat has cost me at least $50 since we moved in. But I didn't need to buy it (yet), the chimney was actually totally clean. oh well.

Wood heat is THE BEST. Quit hating, any doubters out there. If you had a bad experience, you're just doing it wrong.

Edit to add: my wife likes to keep the house over 70F, too. warm, radiating t-shirt weather all winter long.

 

[dodge man]

My way of looking at geo-thermal is that its like a heat pump. The problem is with a heat pump it is using the outside air for the exchange. In the summer if it real hot out, or in the winter its real cold, this exchange loses its efficency. If you use water pumped from under ground, its always the same temp, or close, so the efficency doesn't drop off it the ouside air temp hits extremes.

I just saw LD1's reply, he explained it better.

 

[turnkey4099]

Went back and read everything again. Still fail to see how taxes come into play.

I am simply saying.....How much heat can you buy, if you were to sell the wood and purchase another form of heat. Thats it. No taxes.

For may, yes, firewood is still probably the cheapest.

The whole point of posting is to try to get people to realize that wood has value. Too many people look at all the "free" wood they cut and think they are saving a boat load of money with all their "free" heat.

I used to think the same way. Grew up in an old farm house and fed it 7-10 cord of wood every winter. And hey, that wood cost us nothing more than the time it takes to cut and split it.

And while thats true....., Whats also true is that I could have sold that wood for $1500. So the question is, how much would it cost to heat the same house on propane? $2000 maybe??

So rather than look at burning wood as saving you $2000 a year......You are really only saving $500.

Do not forget to account for the plain enjoyment and physical well lbeing involved. that also has value as much as you don't like the idea.

 

[turnkey4099]

I don't have a beef with you. You're the one that waded in, confusing what I said with selling wood and the resulting tax/no-tax issues from the sale of wood, then saying my statements on taxes were baloney.

Anytime I can produce a head of broccoli, or a cord of firewood, or fix my washing machine, from my own place and use it myself, I consider the fact that buying any of that, I have to add a tax implication that I would have paid buying it, that for me, ends up adding about 35-40% to the so-called cost of the item WHEN DOING APPLES TO APPLES comparison.

Wood still may not work out cheaper....one has to factor in the cost to produce it ( tractor use, chainsaw, splitter, etc) versus buying it even with after-tax dollars.....but using after-tax dollars IS a consideration. That is the point I was making.

Think of it what you may.

Then there is the amoritzation. I have 5 running saws at a total cost over the years of around 2500. Broken down as a per year cost over41 years it ain't all that much. Truck? 1989 bought in mid 90s $3950 and used only for hauling wood, never moves unless I have wood to haul. It also doesn't owe me a penny. Cost to maintain. 2 exhaust sytems and oil changes. Tractor? For what. I get all the wood I can cut withing 30 miles of my house and have never cut a stick that I couldn't drive up to.

Savings in oil over 40 years? I don't even have a guess. I filled that tank 5 years ago (150 gallons to top) at about $3/gal. I don't even want to think about how much oil I would have had to buy without the wood heat. Then able to keep the house at hi 70s, low 80s instead of freezing at 68...priceless.

Added to that is being 82 and still able to cut/split/stack burn Had I not 'wooded' I for sure wouldn't be able to sling a big saw with a 32" bar for hours on end.

LD1 seems to have a vendetta against wood heat.

Thare are many benefits over and above the monetary outlay.