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Natural Gas vs Propane vs Geothermal

Posted by Keadog1 (My Page) on
Sun, Jan 8, 12 at 11:07

I searched and couldn't find any pertinent info. Here's my questions:
We are about to build a new home on a large lot (50 acres). The architect was planning on Geothermal with Propane for hot water, fireplaces, cooktop. Last week I learned there is a gas main 1500 feet from our property line and the gas company will run a main line for about $24K.
So, #1 does this seem cost effective for a planned stay of 20-25 years and would it increase the property values? If so, is there a "rule of thumb" %-wise, for increased value on a large parcel with NG?
#2. Does Geothermal still fit into the equation at all (especially considering the 30% Federal Tax Credit)? Architect says he would not use Geothermal if we have access to NG, saving at least $10K in equipment costs (but we would then need AC). Thoughts?
The house will be smallish - 2600 sq ft ranch with walkout basement.
Am I missing anything in this scenario? Have some time, but hope to break ground April 1.

Follow-Up Postings:

RE: Natural Gas vs Propane vs Geothermal


What is location?

You should do an operating analysis of the various fuel choices.

Make no mistake. You will never recover the $25 K cost of the nat gas line and it will not measurably increase the marketability of a future resale of your home.

Propane tracks oil prices.

Would look at these three options.
2.Carrier's new GreenSpeed HP technology
3.conventional HPs


RE: Natural Gas vs Propane vs Geothermal

Hi Tigerdunes,

I saw you mentioned Carrier's new "Greenspeed" heat pump. I'm just curious, what is the technology behind greenspeed and how does it differ from the current air source heat pump? (I have a Bryant Evolution (1 year old) that I'm quite happy with, but I'm interested to see what that future will bring with HPs).

RE: Natural Gas vs Propane vs Geothermal

The big efficiency advantage of the Carrier Infinity Greenspeed system is that the condenser is inverter controlled variable speed, as opposed to 2-speed.

The cost of the gas line does seem prohibitive.

Here is one possibility to consider since you would like gas for a fireplace, cook top and hot water. You could install a hybrid geothermal/propane system configured like this:

A split geothermal heat pump connected to a Carrier Infinity 58MVB series gas furnace configured for propane with the geothermal heat pump desuperheater and associated buffer tank feeding an instantaneous gas (propane) water heater. This will preheat the DHW to about 110°F feeding the instantaneous gas hot water heater so that very little propane will be required for hot water production. When in the A/C mode, your hot water will be almost free.

At some future date, should the gas line come closer to your home, you could then install it at that time at a reduced cost and convert the gas furnace and instantaneous hot water heater to NG. The Infinity gas furnace is convertible. Just be certain to choose an instantaneous gas DHW heater that would also be convertible. It may be worthwhile to purchase these conversion kits along with the gas furnace and gas DHW heater. Actually, they probably come configured for NG and you would have to buy an accessory kit to convert to propane.

You seem to have plenty of room to install a (properly sized & installed!) ground loop. You may even be able to consider a horizontal loop, perhaps a slinky or a pond loop should you be near water, as well as a vertical loop. You just have to crunch the numbers based on energy costs, tax credits and manufacturer's rebates etc..


RE: Natural Gas vs Propane vs Geothermal

Are you working with a professional energy expert in planning the new home? If not, perhaps you should interview some.

RE: Natural Gas vs Propane vs Geothermal

how much is electricity where you live (total cost with delivery and taxes)? What is your climate and your location? That is alot of money for the gas line. Since your building new you can spend more for extra insulation and maybe 2X6 instead of 2X4 to lower your heat/cool load.

I would consider geo-thermal or a heatpump.

RE: Natural Gas vs Propane vs Geothermal


Based on your options, GT should be in the trade space. It sounds like you are in a rural area. We built in a rural area in 2007 and have a Gt system - propane was our only other option (we only use that for cooking and tankless hot water). Here are some lessons learned from my expereience:

1) Make sure you factor in the cost to run the electrical service to your home AND make sure you get enough amperage. The GT heat pumps need quite a bit of current on start up - my 5 ton heat pump requires a 70 amp circuit and my 3 ton heat pumps require 30 amps. Once the heat pumps start they draw less current - but you still need to factor the start up load into the overall needs for the house. The added cost for additional amperage is relatievly cheap when they install - but very expensive to add later. Based on your house size I would reocmmend a 400 amp service if you go with GT.

2) If you do chose GT, I strongly recommend a propane auxilliary heater instead of the electical heat packs. Have the system wired so that a small backup generator can power the thermostats, the HVAC fan, and the propane heater ingition. That way, when the power goes out you can still have heat. An alternative is to install a larger backup generator that can drive your GT heat pump and loop but that might not be cost effective. Either way - make sure you factor in a backup heating system into your plans.

3) Make sure that the company who is doing the GT system has been in the business for many years AND is available to provide service. These systems have to be designed properly and must be tailored to your specific site and house design. They are expensive and you need to have it done right AND have a reliable company that can service it when needed. If you can't find a highly rated local company to install and maintain the system then I would not recommend GT.

4) Make sure you factor in the building envelope: windows, doors, sealing and insulation into the overall HVAC design. If the envelope isn't tightly sealed and insulated well you won't be happy with a GT system.

5) Do your own research on the Heat pump manufacturers - use this site to ask the experts on the proposed equipment. Make sure it is a quality product.

6) Ask the HVAC contractor what type of monitoring system they provide so that you know that the system is working as efficiently as designed. Mine had nothing and I had to add indicators such as pressure and temperature guages over time.

Goodluck with the build.

RE: Natural Gas vs Propane vs Geothermal

Thanks, all. We are building 2x6 with foam insulation. The home will have lots of windows to capture the views, however. We were already planning GT but all points above are well taken. Will also have whole house back up generator, which is one reason I'm thinking of holding my nose and running the NG line since we are fairly rural and went 6 days without power a few years ago. A site survey has been ordered so I'll get a firm price in a few weeks.
Home site already has electric - we are rebuilding on a site where the original home burned down a few years ago. Well also already in and tested OK with "home" inspection prior to purchase.
Thanks again. Happy to get the advice!

RE: Natural Gas vs Propane vs Geothermal

"...we are rebuilding on a site where the original home burned down a few years ago."

Ouch, are you going to have a pond on the site to provide water to fight fire?

RE: Natural Gas vs Propane vs Geothermal

There is a 21 foot deep, just under 2 acre pond a couple hundred yards from the house.

RE: Natural Gas vs Propane vs Geothermal

You would probably have a better payback with a different shell and passive solar rather than GT. Keep the propane for cooking and backup heat with power outages and just go with an air source heat pump.

Doing foam in the walls is a pretty significant expense that is wasted most of the time. Put two inches of foam sheathing on the outside of your walls and you won't need much heat. Make sure you have a lot of south windows with some masonry inside the house on that side. These things are absolutely cheap compared to $25k for an NG line or the expense of GT.

Of course, you might be in northern Canada and then maybe you should do GT. But generally, you can do a lot better with a good shell. Foam in the walls will be a decent shell but for that cost you could get r-40 walls....

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