OT - Home Heat & AC Question

I currently have an approximate 1400 sq ft home with propane heat and water heater, and window AC units. Last winter I spent over $1200 on propane. I have heard that electric heat is now cheaper than propane heat. My large window AC unit went out and I'm trying to decide between replacing the window unit or switching my propane heater to an all electric heat & central air system.

Anyone know ballpark pricing for an electric heat & a.c. unit?

Should I be looking for a heat pump system?

Any brand names I should look at or stay away from?

Also, I currently have a 100Amp breaker box and it is located on the east side of my house. My utility room where the heating system and water heater is is on the west side of the house. I would like to leave the existing box and wiring alone and just install a new breaker box in the utility room for heat, A.C., and hot water. Is this (having 2 separate breaker boxes) do-able or would I have to upgrade my existing box and run everything through it?

Thanks!

Reply to
RogerN
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You should be able to put a new service, say 200 amps, on the west side. In the new service add a 100 amp breaker and wire to the old service, which is now a subpanel. I believe the ground strap would need to be removed in the old service, since it would be in the new service.

Wayne D.

Reply to
Wayne

It all comes down to the cost/btu (usually shown as the cost per million BTU) in your area for different fuel sources. Heat pumps make electric heat far more cost effective than straight resistance heat in moderate climates. Heat pumps have a "coefficient of performance". That measure is a comparison to straight resistance. It varies depending on outside temp. Don't get bamboozled by the great efficiency of heat pumps, even if the C.O.P. is 4, if your electricity costs 8 times as much as gas, you're still paying twice as much. When it gets really cold you're on straight resistance heat. Using the heat pump for A/C is obviously an added benefit. I live in NY where heat pumps or propane would both be insane choices. Even natural gas at the residential rate is a bit pricey if you have a large house. I buy oil C.O.D. and do my own maintenance. In a warm place like Virginia with lower electric rates, running a heat pump is not a bad deal.

Reply to
ATP*

All over the map, depending on the layout and efficiency. Packaged on the roof, packaged terminal (big through the wall "window unit"), split system, horizontal...

Definitely - Heat pump is vastly more efficient than electric resistance heat. Exception being an air-to-air system when it gets below freezing outside - anything below 25F and the unit is useless, even if it could get any heat from the air the outside coils would frost over and never defrost. Then the system has to shift over to resistance heat or propane.

If you want a ground water based heat pump system in snow country, you need to spend to drill two deep wells that can handle a high draw rate. The water has to be fairly neutral (in PH and not sulfurous or heavy mineral content) or it'll eat up the heat exchanger. And you have to run the well pumps and other extra expenses.

But have someone sit down and run the numbers before you start this. You might be able to beat the efficiency of Propane for space heating with a Heat Pump if your electric rates are reasonable (lots of hydroelectric) and propane delivery rates are high (way out in the boonies). But normally, I'll bet you're better off staying with propane heat.

My suggestion: Change that blown window unit out with a Heat Pump window unit, and any other window units when their time is up, and you are covered for those times when the propane runs out or the furnace breaks /and/ it's warm enough outside to run the heat pump. But it's still probably cheaper overall to heat with Propane.

There are hundreds of name brands out there (one manufacturer might make units under a dozen brand names), and they all buy their compressors and components from a dozen big manufacturers. For example, the compressor will be from Tecumseh, Copeland, Matsushita, Bristol, Manuerop, Danfoss, Embraco, GE, Carrier, Bitzer. I think that's all the biggies...

It's the quality of the parts they choose and how they assemble them that counts, and it's somewhat subjective.

You want to select units with all the good parts like all-Copper coils and internal plumbing, and the proper safety switches like a low-pressure cutout for low refrigerant, and high pressure cutout for failed condenser fans. Other safety parts you need to add, like a Duct Limiter thermostat to guard against setting the wall T-stat to 50 and icing over the evaporator, break delays to keep from wrecking the compressor locked-rotor by bouncing the power, etc.

Guess what I have to do this summer at our house - change out an old natural gas furnace, rip out the old ducts in the attic (wearing a bunny suit and full respirator...) and rework all the ducts and registers, and add air conditioning to retire the swamp coolers... (Aaaaaarrrgghhh!!)

Before you get too far into the planning, you have to call the meter spotter at your local power utility and the local Building & Safety authorities first, and see where they'll *let* you put the new service. For example, they will not let you put a new aerial drop over a swimming pool. This is non-negotiable, they won't connect power to the new meter unless it's properly inspected and permitted.

Or they may require you to switch to an underground service for all new services and upgrades, meaning you get to trench to the pole or the property line and place new conduits for power, phone, and CATV.

And plan ahead. Always put the largest conduits the utilities will allow (a 4" duct for power when they only call for 3"), and a spare conduit for each service while you have that big trench open. Plastic pipe is cheap, labor isn't.

You'll thank me later, when your Telco offers fiber to the home - but only if you have an open duct available. Or your power drop burns up in the duct and won't pull out - use the spare duct, it's wide open. Or when you need to upgrade to a 400A or 1200A power service in

10 years and you don't have to dig it all up again...

Sounds good to me - but most All-in-one panels have the neutral bar bolted straight to the can. You may need to buy a new insulated neutral bar, and leave the old bar in the can as ground only. And put a polycarb blankoff cover over the old meter socket.

And depending on how big the house is, 200 Amps may not be enough to meet your long term needs. All depending on whether appliances get more energy efficient faster than we invent must-have appliances...

400 Amp residential services are becoming more widely accepted and much less expensive. They have a 200 Amp main to feed a remote panel, and a separate 200A main and 20 or 30-slot breaker section for local loads at the garage. Perfect for the home-shop owner who wants to run a BIG welder or lathe.

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Reply to
Bruce L. Bergman

OK, someone is going to have to explain this one to me. At least two of you have claimed heat pumps are more efficient than resistance heaters. I don' t see how.

Converting electricty to heat through a resistance element is pretty much 100% in my mind. The only "losses" are due to needing some fans. The inefficiency of the fans shows up as....heat, so I don't think those matter. How in the world can a heat pump be more efficient?

Steve

Reply to
Steve Smith

They really move heat from the outside air into your house, just like your refrigerator extracts heat from the refrigerated compartment. see-

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Reply to
ATP*

That's a good explanation page. Instead of turning 100KwH of electricity into resistance heat, you can use 20KwH to move the same amount of heat inside from the outside.

Where the efficiency of using Propane, Oil, Natural Gas or other fuels directly for space heating comes in is through the transmission losses in the electric grid. The average fuel-fired power plant is at best 50% efficient, and you lose another 10% to 20% in transmission losses. Meaning the same amount of oil or gas that would get you

100KwH of heat when burned in the furnace at your house is only going to get you 30KwH after it's converted to electricity and shipped to your house.

Those losses didn't do you any good - they dumped a lot of waste heat up the cooling towers at the powerplant, and a lot of waste heat off every step-up and step-down transformer and each less-than-perfect splice in the power distribution chain, all of which you can't harness.

The only reason it is not more efficient to buy the raw fuel, run your own generator and make your own electricity at home is the equipment costs and basic economies of scale. Paying for the 70% losses is usually still cheaper than buying and maintaining your own set of generators (you need two so you can stop one for maintenance) and running one of the pair all day every day.

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Reply to
Bruce L. Bergman

Thanks, I figured this out about two hours later (after I woke up).

Steve

Reply to
Steve Smith

You might also consider adding solar heating panels to reduce at least the daytime load on whatever propane/resistance/heat pump system you go with.

-- Morris

Reply to
Morris Dovey

Your own set of generators will also be quite a bit less than 50% efficient, IIRC. Cogeneration can recoup some of that loss by using the heat for heating or cooling, but even those schemes depend on reducing the peak demand to make the numbers work. If you're not a demand customer it just doesn't make sense. In general cogeneration plants have not been a good bet for small to midsize commercial/municipal entitities, even in downstate NY with our high electric rates. They've worked out on some big university campuses, the rest have been abandoned for the most part. Another flop so far is microgenerators, small turbines that were supposed to decentralize power distribution.

Reply to
ATP*

Electric air to air heat pumps are 2 to 3 times (sometimes as high as 4 x) more efficient than plain electric heat strips. They gather heat from the outside and transfer into your house. Work good down to about

20 degree F. Below that they are just slighty more efficient than the plain electric heat strips... never less.

Geothermal maintain the 3 to 4 COP rating because they are using heat from the ground loop. Much more expensive to put in than air to air heat pumps. Payback only if you plan on staying in the same house for 20 years or so. Payback can be as short as 5 - 10 years depending on your local propane or other fuel costs. B.G.

Reply to
MachineShop

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