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Converting from steam to Geothermal?? (13 Posts)
Converting from steam to Geothermal??I need to replace the boiler on my steam system (over 20yrs old). Want to know how feasible it is to replace the steam system with an energy efficient geothermal system. I know it will be more expensive but since Ii do not have central air now, the summer cooling would be an important added benefit.
I believe I have space for installing a closed loop system near the house. All the geothermal systems I have seen on-line seem to be for either hydronic or ducted systems. I do not have ducts now and installing throughout the three story house is not really an option, I also do not like the look of baseboard hydronic systems.
What options do I have? Does it make sense to install 2 units (basement and attic) to reduce the ducting complexity? Does any of this make financial sense versus upgrading the boiler to a high efficiency model and then adding central air?
rads?I've retrofit several homes with geo using panel radiators; much more robust, good looking (imho) and work better using less space than baseboard at low temps.
Anything is feasiblebut the question is: Is it the best option/solution for you? 20 years for a boiler doesn't seem that old. What part of the country do you live in? Depending on the climate, a ground source heat pump (GSHP) may or may not be an great energy saver. Heat pumps do not produce high enough water temperatures to provide heat in most instances. Infloor heating in very well insulated houses or in mild environments can work effectively, though.
Splitting the the cooling systems between floors makes good sense, for comfort as well as for ducting concerns. For any practical central AC system, you will need to have ducting. There are "ductless" split, single and multi-zone options, too. These types of systems can be heat pumps, but are only available in the standard air-to-air type.
Your options include: Replace/upgrade the boiler without cooling; replace boiler and add hi-velocity AC (small ducts, great for retrofits in hydronic only houses) or ductless AC; replace boiler system with GSHP heating/cooling system(s); maintain existing boiler for now and get estimates for various options and see what your budget will bear.
Any installation is feasible, iof you're willing to do it or pay someone to do what is required. Some will cost more upfront and have potential for savings in the long term. Some options will cost less now, but more in energy consumption over he long term.
GEOit is my understanding that Geothermal works well when using either a forced air system that heats and cools the house or radiant heat for heat and forced air to cool. I don’t think it works well with radiators since radiators have to reach approx 180 deg in temp. Geo I believe reaches up to only 120 deg. because it reaches up to 120 deg it works well with radiant heat, forced air and even can provide domestic hot water since 120 is more than enough to heat the water. So I believe you may have problems with the steam. I would install a furnace up in the attic and one in the basement. the tubes come from the ground either horizontally or vertically into a manifold. out of the manifold are a supply and a return that connect to a heat pump in the furnace. If the tubes that are buried in ground engineered properly which when the water/antifreeze closed loop system gets to a temp of 55 deg, the heat pump doesn’t have far to go to make 70 deg temp to heat and say 40 deg temp to cool. For the heat pump that’s located in the furnace another supply and return tube is connected to a tank that will provide domestic hot water. This is new to me but I have seen it done twice so far and they work great and the upfront cost is reached say in a few years and your oil/gas bill is nonexistent. Down with oil and Gas! Im doing it this year, im sold.
rad sizingRadiators can run at any temperature, but they must be sized for that temperature: smaller for high temps, larger for low temps. any rad manufacturer will give you a correction sheet to tell you a given rads output at a given temperature. Like I say, I've done several geo installs with them and they work great and are easier to retrofit in existing buildings than forced air.
How far do you want to goFirst step for your consideration would be an accurate heat loss calculation including a blower door test. This will tell you how many BTU's you need for your house. 2nd installing a geo system that intergrated cooling and radiant heat is complicated. So choose your contractor wisely. After figuring out your load calc you can then determine how many tons of geo you will need then converting to how much land you will need for the loop field. If you able to make this all work get a payback schedule. Right now natural gas prices are at an all time low. Electric prices are more stable but are on the rise. Don't forget your 30% tax credit for the entire cost of the job. My guess is your home will need more btus than a geo system can safely give you without some sort of electric back up. Explore the option of converting your radiators to hot water and a high eff mod con boiler with built in reset control. Most of my business is installing geo and with that I have great sucess and a few failures. Tread carefully.
Wall of Shame??Is the photo of the heat pump there for consideration on the Wall of Shame? There is so much WRONG with this install...
Wall of Shame??Duplicate post removed.This post was edited by an admin on March 17, 2011 8:41 AM.
Geogreat!!!!Interesting comment on how ugly the picture is.
This application was installed 4 years ago and is working great.
its right out of the hand book on "do it yourself Geo"
so far after 4 years in upstate New York where temperatures reach below 30 degrees all winter long, ive yet to have any problems. as a matter of fact the only problem i have is what to do with all the money ive saved in the past few years.
Please tell whets wrong I’m new to this Geo
DIYMr Monegrand.if you are happy with the install then that all that matters.
To be perfectly honest your install looks like you might be the kind of person that cant see the forest for all the trees.
First off no permit or inspection.Service panels blocked.No shutoff valves,no hose bids and no pete plugs for testing.Being i dont see a solenoid valve i can only assume you have a bleed down system.It would be best to keep that water coil charge durning the off cycle.
Lets hope that your pressure switch do there job and take out the system with loss of water, bc if not that sch40 pipe you have at the heat exchanger will get soft and pop loose from the water coil.
Not even going to get into the issue of the distribution on the airside.Just let me say its a good thing this is a hobbie for you and not how you make a living.i wonder how much more money you could save if that unit was install and setup correctly.Hmmm
Wall of shameOn top of what Don said... This should have been a horizontal install. Were you to post photos of all four sides the Wall would probably gasp!
Remember what Dirty Harry said... Man's got to know his limitations
A complete tear-out and replacementwould be much, much more expensive than replacing the steam boiler with a better one. Also it's a messy, disruptive operation. And don't forget it costs something to pump all that water and run those compressors. The savings in winter might be much less than you think.
What kind of boiler do you have now?"Reducing our country's energy consumption, one system at a time"
Steam, Vapor & Hot-Water Heating Specialists
Oil & Gas Burner Service
Baltimore, MD (USA) and consulting anywhere.
I think you can get mostOf what you want by adding mini-split heat pumps to the house. They are pushing the efficiencies of geothermal and offer the best zone control for far less than geothermal. Keep your steam system maintained and you choose your balance point. Perhaps best of all, you can do mini-splits in stages.