Heat pump replacement

[Dick Adair]

I'm planning to replace my 18 year old Rheem heat pump this summer as I could see a difference in it's efficiency this winter. With the caps coming off electric rates next year, I'm considering either a gas back up or going to a thermal unit. Thermal meaning drilling a well versus burying lines. I have city gas in my house now used only for water heating and a gas grill. Full time gas heat creates a humidity problem. I'm leaning towards thermal and the well but I think this would be more expensive. Can anyone give me any ideas which might be the better choice. Thanks in advance for any advice.

[Robert Parrish]

Take a look at Trane. I replaced my entire system a few years ago and lowered my electric bill 20-30%. I also had a Trane when I lived in Va and never had a problem with it.

[Ken Garlock]

Hi Dick. I have a Trane heat pump for my shop. It was installed when the shop was built back in 2002. It does a good job both summer and winter.

I am not clear on what you have now as I was confused by your out of the clear injecting comments about thermal alternatives. I had a 5 ton Water Furnace geothermal system installed when we built and it can keep the house at comfortable both winter and summer. However, to accomplish that required 4 wells each of which is 300 ft deep. The depth is necessary to get down to a constant soil temp of 60 degrees. The evaporator is by Trane, and had be replaced under warranty in the first couple years of use. The system has no supplemental resistor heat and has kept the house at 68 in temps down to the middle teens. We seldom go below 10 degrees.

Personally I would be reluctant to use a heat exchange system other than a well.

I am sure that Lee Schierer in Erie PA. can give some better info :)

[David G Baker]

My neighbor just had a geothermal system installed. The unit is supplied by his well water and is dumped in an area of his property that is considered wetlands. His installer did not do a check on the well water quality but his plumber did. The plumber even told him that his water was good enough that he didn't need a water softener for his house water needs. He already had a softener so he had the plumber hook it up weather he needed it or not. After about a month he noticed that the amount of heat supplied by his heating unit was dropping off so he called the geothermal installer and had him come out and check the unit. There is a filter in the water line before it enters the unit, the filter was almost totally plugged by iron and minerals. Guess the plumbers testing of the water may have been off.
If I have one of the units installed I am going to get the loop type because my water is also loaded with minerals. I have plenty of room to do the trench type.
If you plan on using the dump well source type of unit you will need to do some serious ground water testing.
The loop type units may cost more to operate because of the circulating pumps running all the time.

[Dick Adair]

Dave, we cannot remove water from the well. They put a ban on wells 20 years ago after our water company went to wells for our municipal supply. As I understand it, they run a pipe into the well and transfer the 50 degree temp to the water in the pipe, then run the water through the heat pump. I think it takes a deep well to get the capacity you need for the heat source.

[Paul Ryan]

Dick,

I am confused why full time gas would cause a humidity issue. The burning gas is in a seperate chamber than what the air passes through. Besides that we can us all the humididty we can get in the winter time. It is so dry around here in the winter that many people run humdifiers in the winter.

I just installed a heat pump this past autumn. The heat pump I installed was a Carrier rated at 17 seer. I used this and an electric plenum heater for my heat source down to 0 degrees. If the air temp went below that my furnice automatically switched over to LP. I considering this was one of the coldest winters we have had in a very long time, I came out real well. I only used 200 gallons of LP for a 3600 sq ft home. All in all I went this route becasue since I live in a rual setting my electic coop sells electricity to me at 50% off if I am on a metered system. They shut it down during peak times for up to 6 hours. If I need heat during those times my furnace switches over to LP again. by switching my heat and hot water over to electric this year I saved about $1000 this season. For the upcomming season I wont save as much because LP prices have dropped considerablly. But as effcient my heat pump and plenum heaters are I have to buy LP for $1.00 gallon to compare to electicity at $.06 KW Hr. I dont expect LP to ever come close to that again. Last june it was $2.40 a gallon. currently it is $1.76 a gallon. It is a big chunk of $$ to shell out up front expecially if you need LP as a back up. I already had the LP system so it cost me 1/2 as much.

[Dick Adair]

Paul, humidity issue as too dry. I can't tolerate heated air from a furnace. I know gas back up is dry, but that is only needed a small amount of time. I have a Herrmidifier in my air system and it is clogged more than it works. Stand alones are a pita.

[David G Baker]

Dick they did the same thing with wells in the area of California that I lived in several years ago. They charged an arm and a leg for metered water. During one of the never ending droughts in Northern California they raised the price of water to the point that is was close to the price of other utilities. A couple of friends drilled their own wells using the small portable rigs so they could water their gardens. If they had been caught they would have been fined severely.
The well loop type geothermal heating systems are the type that folks use if they have limited real estate. Like you wrote, a 300 foot deep well or several, depending on system demands is normal.
My neighbor that had the geothermal system installed because the local natural gas supplier wanted close to $3000 to run a gas line to his home. He has a set back of close to 1000 feet from the nearest natural gas line.
He doesn't know yet what he is going to do about the minerals in his water supply. Not sure if it would be cost effective to use softened water or what other problems could pop up.

[Gary Click]

I have been using a Dual Fuel System or combined Heat Pumps and Gas Furnaces to heat and cool my house by about 12 years. Currently we have a 4 ton/96kbtu system, a 2.5ton/45kbtu system and a 1.5t/30kbtu system.

The way the systems are configured is quite simple. The Heat Pump is installed in the system as usual and instead of an Air Handler Cabinet a Forced Air Gas Furnace is installed. There is a thermostat located in the outside unit that monitors outside ait temerature. When the outside air temperature is above the thermostat set point the system runs as a Heat Pump. When the outside temperature drops below the setpoint the Heat Pump is shut down and the Gas Furnace is used. The systems perform as A/C units in the summer.

This allows both the Heat Pump and the Gas Furnace to operate in their most economical range. Currently my setpoint is 45F.

[Paul Ryan]

Dick,

I thought you were talking about too much humidity. My bad. I know what you mean about forced are it is just to dang dry. The whole house humidifers don't work very well. I haven't installed on due to country water. My brother lives in town and with a H2O softener is has worked real well for about 5 years.

If I ever build a new house I will install radiant heating and be done with it. I hate forced air, but it is what was here when i bought the house.

[Lee Schierer]

I've had a geothermal heat pump operating from two wells for over 25 years. The wells are 100' apart and I pull water from one and return it to the second well. Last summer I replaced my system with a new geothermal heat pump and air conditioning unit. So I now heat and cool my house geothermally. The unit cost about $9,000 installed. It has worked great. We used less KW this past summer than we did the previous year running fans. We also heated through he winter with no problems despite a week of temps at zero to sub-zero. We are total electric and our electric bill is $135 per month. No other utility bills. We heat and cool about 2200 sqft, including my shop. The unit we purchased has two stage heating and cooling and a variable speed fan. I believe it is actually made by Comfort Aire, but came packaged with both Bryant and Carrier nameplates.

A single well system needs a deep well. The water is put in at the top and removed from the bottom (I believe). The water picks up heat from the ground or dissipates heat in the cooling season. It has no effect on the water table. Our local county Library heats and cools from 200 wells under their parking lot.

Do a search for "heat pump payback calculation" in google and you should find a spreadsheet that will help compare the operating cost of different units to your present system.