Furnace Replacement

[tvgordon]

Hi everyone,

With natural gas prices rising anywhere from 35 to 50%, I'm going to need to replace the furnace in my house.  Currently it is a old gravity feed - converted from coal - ductwork wrapped in asbestos furnace heating the house.

My question is what to ask the dealers/ installers when I'm taking bids?  What, if anything, I should watch for when I'm getting estimates?  An example would be, when I had an estimate many, many years ago, they said the main floor heating ducts would have to be moved (they're toward the center of the house) and they couldn't do anything with the second floor ducts.  I'm also considering adding central air and maybe a new system for the workshop.

I just got a bunch of bills paid off so I might as well go into debt again.

Tom.

 

[vteknical]

Tom,
If it's a matter of just a furnace replacement, this is something you could probably you can tackle yourself.

Many homeowners soft install the furnace, plenum, A-coil(Refrigeration Evaportor), Condensor, line set, pad, disconnect wip etc.  Then have a professional come out and go over the refrigeration lines, gas, exhaust and start it up.

I don't know your what your limitations are so I threw that out there because installation cost are going to cost as much as equipment if not more.  You can save a bundle tackling this yourself.   

Things to consider:  Furnace efficiency(two stage of single, variable speed of single speed blower, don't get too caught in brand names, electronic media filter, humifier, house size, windows, their efficiency and where they are facing, fresh air system.

In the world of HVAC bigger is not better, the equipment needs to be sized to your home. 

There is a lot to cover, pPerhaps you can provide some information about your home and future plans.  This will help the qualification process. 

Victor

 

[John Langevin]

TVGordon,
    As VKTechnical pointed out, the volume and climatic conditions are very important, his most important comment was 'bigger is not better"; the system must be sized correctly.
    A few years ago I upgraded the gas furnace in my 3,000 sq.ft. 1870's Victorian in the course of finishing my basement. I was never happy with the results; later on, as I was completing the basement, a friend who worked part-time in HVAC was over and pointed out several 'flaws in my system'.
    Originally I had one large return duct in my front hallway, this was inadequate and resulted in a 'pressurized house' [which can leave you locked out!]. The first guy added return ducts at the outside edges of the first floor rooms and had a supply duct underneath the thermostat. My friend and I re-routed the entire first floor system by placing all supply ducts at the perimeter and adding several return ducts near the interior. What a tremendous difference!
    It will pay to consult a professional to design and spec out your system. The basic install and ductwork you can do yourself (if you so desire) and then as VKT suggested have a pro seal the deal.

 

[tvgordon]

It's funny you guys mention furnace size, because when I was getting bids the first time they gave me two prices for two different sized furnaces.  Buy the right size for the house and no bigger - got it!

I'll tackle most any home improvement items, but for some reason installing a furnace just seems too overwhelming.  Maybe because I know so little about it.  Soon I'll start getting estimates and see what the different companies recommend I have done. 

Victor, I'm glad you said don't get caught up in brand names, because I was going to ask if one brand was more dependable than another.  I'm not sure what else I can tell you.  The air intakes are under the windows and the heated air vents are along the inside walls.  On the second floor two of the vents are in the outside wall and one is in an inside wall.

Tom.

 

[vteknical]

Tom,
I assure you replacing a Furnace may appear to be overwhelming but it's really not that bad.  Think of it as a built in appliance.  Most of the time much of the work spent on modifying and connecting plenum to the homes duct system. 

I guess, my first line of business would be to assess your home's needs by a professional.  If you are able to tie into the existing duct work you are already a step ahead of the game.

Since you are already working on the furnace and plenum makes logical sense to add the air conditioning components.
This is a straight forward process that you really do not need to be certified to do.  For the condenser installlation you will need:
Find a location for the unit.  Preferably somewhere in the shade, away from areas where you entertain.
You will need to run 220v to the unit.  If this is something you can do, you will save yourself 700-1000.00  Material cost approx 125-150.00 nice savings.

You will need to make several penetrations to your home.  1st will be approx a 1" hole for the refrigeration lines.  Second for the 220v electrical line for the disconnect box.  Third you will need two 2 1/2" to 3"
penetrations for the furnace's intake and exhaust.  If your going to be drilling through concrete or brick, I highly recommend renting a Hilti drill and coring bits from H-depot.  Takes about 10 minutes and leaves a much better finish.

Your probably thinking"easy for him to say"  Tom I don't know your skill set, but if you are a DIY'er I would rate this a 7 on difficulty.  Your biggest challenge is going be obtaining information to minimize the learning curve.  Also, this is a great time to handle project yourself since you don't have AC to begin with and don't need the heat to keep you warm.

First have your home evaluated by a "no pressure" HVAC professional.  If you think you are up to the challenge please feel free to contact me via email and I will happy to layout an installation matrix for you.  I can also call my friend at Johnstone Supply to see if you can purchase the supplies under my account and pick it or ship to your state.

Victor

 

[stvrowe]

I have but one recommendation.  Can the gas completely and go with a ground source heat pump.  I did this 3 years ago and am exceeding my estimated 8 year payback.  The first year alone, I saved over $850 in utility bills (both gas and electric).  I now have no gas bill and the electric bill went down due to the much improved efficiency of the cooling unit and the free hot water from the de-superheaters.  I would do this again in a heartbeat.  My only regret is not adding HVAC to the shop too.
Steve

 

[b_m_hart]

I have but one recommendation.  Can the gas completely and go with a ground source heat pump.  I did this 3 years ago and am exceeding my estimated 8 year payback.  The first year alone, I saved over $850 in utility bills (both gas and electric).  I now have no gas bill and the electric bill went down due to the much improved efficiency of the cooling unit and the free hot water from the de-superheaters.  I would do this again in a heartbeat.  My only regret is not adding HVAC to the shop too.
Steve

Have any links to info on this?  The tag on my furnace is dated December 1972, so I'm in the market for something new as well.

 

[stvrowe]

I have but one recommendation.  Can the gas completely and go with a ground source heat pump.  I did this 3 years ago and am exceeding my estimated 8 year payback.  The first year alone, I saved over $850 in utility bills (both gas and electric).  I now have no gas bill and the electric bill went down due to the much improved efficiency of the cooling unit and the free hot water from the de-superheaters.  I would do this again in a heartbeat.  My only regret is not adding HVAC to the shop too.
Steve

Have any links to info on this?  The tag on my furnace is dated December 1972, so I'm in the market for something new as well.

I have two units:  A Waterfurnace (downstairs) and a Trane (upstairs).  Waterfurnace info is: http://waterfurnace.com/residential.aspx  (sorry, can't figure out how to make this a link)

The reason for the different units is the Waterfurnace is not available as a split unit from the air handler and the Trane is.  The air handler for the upstairs is in the attic (the hottest place of course) and the heat pumps are in the crawl space.  There is no equipment outside other than the pipes in the ground.  I actually prefer the Waterfurnace as the air handler fan is variable speed where the Trane is a 2 speed.  For the hot water heater, I went with the Marathon 85 gallon which is all plastic and guaranteed for life to not leak.  De-superheaters (sends hot water to water heater from heat pump waste heat) were optional and I recommend it. 

Depending on how rocky your area is or how much space you have will determine whether you need wells or can lay piping in trench.  Folks that install in your area will know what you need.  I needed wells because of the rock.
Steve

 

[tvgordon]

First have your home evaluated by a "no pressure" HVAC professional.  If you think you are up to the challenge please feel free to contact me via email and I will happy to layout an installation matrix for you.  I can also call my friend at Johnstone Supply to see if you can purchase the supplies under my account and pick it or ship to your state.

Victor

Victor,

Thank you so much for your generosity!  I plan to begin getting estimates later this month and will get back with you if I decide to do it myself.

I have but one recommendation.  Can the gas completely and go with a ground source heat pump. 
Steve

Steve,

I will look into your recommendation too.  I'm guessing since you mentioned an 8 year payback that the initial investment is larger than a traditional furnace/ air conditioner?

Tom.

 

[peter halle]

Groundsource heatpumps are indeed much more expensive than the normal systems.  They extract their heat and shed their heat to the ground.  The colling lines that shed or gain the heat must be buried or inserted into wells that must be dug.  If you have a pond of sufficient size it can be used.

They are more efficient than conventional systems because the shedding or gaining of heat ' energy is in a more controlled environment.  Once you dig down 6 to 8 feet the soil temperatures are more stable then the atmosphere at ground level.  By example  a heat pump trying to get heat from the outside air at 30 degrees will have a harder time then if that outside temperature is 50 degrees.  Same thing in summer - shedding heat in a outside temperature of 90 will be harder than at 50.

I don't have one - I have done some investigation and will continue to do more.  I also understand that they are significantly quieter than normal systems.

One other thing - ground source heatpumps can be used in regions of the world where the normal climates would prevent a conventional system.

Good luck.

Peter

 

[tcooper4653]

I have but one recommendation.  Can the gas completely and go with a ground source heat pump.  I did this 3 years ago and am exceeding my estimated 8 year payback.  The first year alone, I saved over $850 in utility bills (both gas and electric).  I now have no gas bill and the electric bill went down due to the much improved efficiency of the cooling unit and the free hot water from the de-superheaters.  I would do this again in a heartbeat.  My only regret is not adding HVAC to the shop too.
Steve

Have any links to info on this?  The tag on my furnace is dated December 1972, so I'm in the market for something new as well.

I have two units:  A Waterfurnace (downstairs) and a Trane (upstairs).  Waterfurnace info is: http://waterfurnace.com/residential.aspx  (sorry, can't figure out how to make this a link)

The reason for the different units is the Waterfurnace is not available as a split unit from the air handler and the Trane is.  The air handler for the upstairs is in the attic (the hottest place of course) and the heat pumps are in the crawl space.  There is no equipment outside other than the pipes in the ground.  I actually prefer the Waterfurnace as the air handler fan is variable speed where the Trane is a 2 speed.  For the hot water heater, I went with the Marathon 85 gallon which is all plastic and guaranteed for life to not leak.  De-superheaters (sends hot water to water heater from heat pump waste heat) were optional and I recommend it. 

Depending on how rocky your area is or how much space you have will determine whether you need wells or can lay piping in trench.  Folks that install in your area will know what you need.  I needed wells because of the rock.
Steve

Follow the link you have above, WaterFurnace offers the Envision series in both an indoor and an outdoor split and offer the matching air handler for the indoor portion.
TC

 

[tvgordon]

One other thing - ground source heatpumps can be used in regions of the world where the normal climates would prevent a conventional system.

Good luck.

Peter

I don't know why, but I was under the impression that heat pumps only worked in relatively mild climates - not too hot or too cold.

Tom.

 

[peter halle]

The beauty of a ground source heat pump is that you are not dealing with air temperature.  The deciding facture is ground temperature at a given depth.  Imagine a cave in the middle of the summer.  It is cooler than the outside air.  Well your heat pump wants to get rid of hot air.  It is easier to get rid of hot air to cold air than  it is to already hot air.  Let's go to winter.  I live in Virginia and winters are not brutal, but this region is on the border line of whatworks for a heat pump.  A typical winter night.  Temperature outside is 29 degrees.  A heat pump will try to extract heat out of the outside air.  Not much there I guess.  Now let's go downstairs into the earth.  That heat pump may be be trying to get heat from a place that is 50 to 60 degrees based on the design of the system.  A whole lot more efficient.

Please don't be insulted by the wat I try to explain this.  It's just my way - It is not meant to reflect on any knowledge of you or anyone else.

Ground soource hatpump systems need to be designed based on the local climate.  The basis is just like you car.  The radiator uses airflow to cool the water in the cooling system.  This system uses this in the earth to do so and the earth at the appropriate depth is more constant.

If you are more interested, just let me know and I will try to pull together some articles from some magazines.  It is a wonderful concept  in this country it just will not become affordable unti the energy costs become too high.

Just my thoughts,

Peter

 

[stvrowe]

Peters description is accurate.  Once you get deep enough, the ground temperature is fairly constant year around.  My system has 4 wells 240 feet deep and has closed loop piping that loops up and down through each of the wells in series.  This gives me approximately 2000 ft of piping for heat exchange.  Another option for the piping is to lay them in trenches about 6 feet underground.  This is not practical where I live due to rock hence drilling wells is the preferred approach.  The ground source heat pump has no emergency heat strips since it is not dependent on outdoor air temperature as a heat source.  When heating, the temperature feels warm and keeps the house comfortable which was not my experience in previous heat pump homes I have had.  The discharge is not quite as warm as a gas furnace but is not dry either. 

For a good description of how this works, I recommend checking this link out:  http://www.dougrye.com/geothermal.html    Doug Rye has a radio program and this is what led me to considering a ground source heat pump.  I just wish I heard about him before I built.  His show is live Saturday 9-10 am CST on various stations thoughout the country.

As to cost, it was about double the cost of a 14 SEER air source heat pump.  The hardware was more expensive but, the big expense was the drilling of the wells. 
It's ashamed we didn't hit oil.

Steve

The beauty of a ground source heat pump is that you are not dealing with air temperature.  The deciding facture is ground temperature at a given depth.  Imagine a cave in the middle of the summer.  It is cooler than the outside air.  Well your heat pump wants to get rid of hot air.  It is easier to get rid of hot air to cold air than  it is to already hot air.  Let's go to winter.  I live in Virginia and winters are not brutal, but this region is on the border line of whatworks for a heat pump.  A typical winter night.  Temperature outside is 29 degrees.  A heat pump will try to extract heat out of the outside air.  Not much there I guess.  Now let's go downstairs into the earth.  That heat pump may be be trying to get heat from a place that is 50 to 60 degrees based on the design of the system.  A whole lot more efficient.

Please don't be insulted by the wat I try to explain this.  It's just my way - It is not meant to reflect on any knowledge of you or anyone else.

Ground soource hatpump systems need to be designed based on the local climate.  The basis is just like you car.  The radiator uses airflow to cool the water in the cooling system.  This system uses this in the earth to do so and the earth at the appropriate depth is more constant.

If you are more interested, just let me know and I will try to pull together some articles from some magazines.  It is a wonderful concept  in this country it just will not become affordable unti the energy costs become too high.

Just my thoughts,

Peter

 

[WaterFurnace]

Steve,

WaterFurnace now makes both an Indoor Split and an Outdoor Split heat pump. In addition, we now have our own AHRI rated Air Handling Unit to provide a matched system where a package unit like our Envision system will not work. Or where a homeowner wants to use a natural gas furnace as their backup heat source, they can use our AHRI rated DX coil.[/quote]

 

[peter halle]

Steve and anyone interested in ground source heat pumps,

I offer the following:

In the early to mid 1990's I worked for a catalog showroom retailer (Best Products) in their corporate headquarters as a construction project manager.  I was part of the Facilities Department and was also in my later time there was responsible for capital maintenance / replacements of infrastructure in stores west of the Mississippi.  Great company to work for.  Anyway, the person in charge of the corporate facilities maintenance at the headquarters and responsible for the same things as I but east of the Mississippi installed a ground source heatpump in his home.

The industry has come quite a ways since then, but I can tell you that he loved the system.  Almost totally quiet (todays are even better), energy efficient, etc.  Now this guy was responsible in his day job for one of the most advanced heating and cooling plants in existence at the time.  I could tell stories of it's capacities upon request, so the fact that I decided on such a system has always been a sound recommendation in my mind.

Peter

 

[tvgordon]

Thanks Peter, I understood the basics of the system.  When I had heard that heat pumps worked best in mild climates, it was probaby not refferring to ground source heat pumps.

Steve, I would have to call someone, but I live in the city limits and yet to see anyone drilling a well.  They probably just dig a trench, but I could be wrong (it's happened once or twice ).

It seems a ground source heat pump would pay for itself in the long run.  But my wife and I haven't decided if we are going to try to sell the house in a few years and move out of the city.  If we are going to stay, the heat pump would be the way to go.  If we are going to sell, we will install a furnace because the houses in our neighborhood don't sell for much and they don't sell quick.  :-\

Tom.

 

[stvrowe]

Waterfurnace - glad to hear it is available in both.  I suppose it wasn't available about 3 years ago since my HVAC contractor really preferred the Waterfurnace.
Steve

Steve,

WaterFurnace now makes both an Indoor Split and an Outdoor Split heat pump. In addition, we now have our own AHRI rated Air Handling Unit to provide a matched system where a package unit like our Envision system will not work. Or where a homeowner wants to use a natural gas furnace as their backup heat source, they can use our AHRI rated DX coil.

[/quote]

 

[stvrowe]

Tom, I hear you.  I struggled with the same decision since we are now empty nesters and were considering downsizing.  The rate natural gas was going up at the time tilted me over to the heat pump.  I think I will be in this house at least another 2 years so will have most of the payback complete if not all.  I really look at the ground source heat pump as being a good selling point (assuming there are buyers of course).  If I knew for sure I would be moving in 5 years or less, I would not have gone this route.
Steve

Thanks Peter, I understood the basics of the system.  When I had heard that heat pumps worked best in mild climates, it was probaby not refferring to ground source heat pumps.

Steve, I would have to call someone, but I live in the city limits and yet to see anyone drilling a well.  They probably just dig a trench, but I could be wrong (it's happened once or twice ).

It seems a ground source heat pump would pay for itself in the long run.  But my wife and I haven't decided if we are going to try to sell the house in a few years and move out of the city.  If we are going to stay, the heat pump would be the way to go.  If we are going to sell, we will install a furnace because the houses in our neighborhood don't sell for much and they don't sell quick.   :-\

Tom.

 

[tvgordon]

Well, I ended up having a natural gas furnace and heat pump (not ground source) installed. It took 3 guys 3 days to tear out the old furnace (dated 1937) and install the new equipment and ducts.  I went with the heat pump mainly so that I won't use any gas until it gets real cold outside (now watch them raise electric rates :'().

vtechnical, I really wanted to do it myself, with your guidance (especially after I started getting estimates), but it would have taken me a long time to do what they did.

Tom.