HVAC Heating Zone question

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I am in the process of building a 3000 SQFT house that my builder spec'ed for two zone heat. He called my yesterday and said after he met with his mechanicals subcontractor that two zones were probably not enough since the room over the mudroom and the room over garage were (I guess) to far away from the furnace to be efficiently heated. He was suggesting we add a heat pump for those two rooms (with AC of course). We live in Northeast and I am worried this would be terribly expensive solution. I questioned him about adding a third zone and he said he'd get back to me after talking to the sub again. Does a heat pump make sense? I don't understand why a third zone couldn't be added fairly easily. Is this a cost issue? Wouldn't a larger BTU furnace do the job? Our contract specified two zone heat, is this something I should have to pay extra for or would this be his cost. Thanks in adavance for any advice you have.
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There are plenty of options. Unless you're getting cheap hydropower, don't even think about going with a heat pump in the Northeast. Energy-wise it's about as bad as electric heat, and even worse after you factor in the equipment cost, the installation cost, and the maintainence cost.
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Talk to another mechanical contractor. We can't see the layout of the rooms so it is not possible to give sound advice. You mention furnace. Is it going to be hot air heat? If so, distribution may be a problem in those areas and not very efficient. You also will need a huge furnace heating up when only two rooms need the heat. There are losses there. Potential big loss.
Do you mean a boiler with zoned hot water? Easier to distribute, but still some losses along the way.
Get another opinion. As for cost, there will be a line in there for heat. Dropping those rooms from the original plan will offset some, but probably not all, of the heat pump cost. Not having read your contract, I don't know if it is a variable or not.
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This is Turtle.
One thing here and when there is any changes to the first aggreement -- You are going to pay for it. There is a old rule in the hvac business that says when the contractor starts paying for the system to be installed , He should not do the job.
Now using a Heat pump for the 3 rd zone : You may look at a another gas / hvac system / hot air type system just for the 3rd zone. Now Heap pump is still not out of the question for the cost of a heap pump and another gas or oil heating system are not much difference on cost. The Heat pump may be a little cheaper for not having venting system and oil or gas lines run to it.
Now having a small area heated by a heat pump would not be a big cost item for operation but gas or oil fuel would be a hair cheaper.
Now when you have a 3rd zone far off from the other 2 zones does make a problem with tring to keep a even heat in all zones. I can't see it from here but this is what it seem to be here.
Don't listen to [ Ha Ha Budys here ] for he is our resident Troll and want to feel like he is somebody.
TURTLE
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I'm the resident troll?
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This is Turtle.
Yea, for one statement on the heat pump. You stated that the heat pump would cost more and cost more to install. I do this for a living and the heat pump cost less than a gas fired furnance, evap. coil, and condenser. On the 6 brand I sell the heat pump runs about $60.00 to $100.00 cheaper to buy wholesale than the gas furnce/ coil / condenser. Also it take less time to install a heat pump than a gas furnce coil system. You speak before you think or you don't know about it.
Now the heat pump being more costly than a gas furnce heat is too verible to try to say cost to operate it is high or lower to run because of fuel difference in the different areas.
Now to being a troll or not. A troll speaks to get a adverse reaction from the newsgroup. Some speak a lot of differences and other just a little to get a reaction. Do you do this ?
TURTLE
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[original post is likely clipped to save bandwidth]
wrote:

Turtle,
Down in your area (LA) air exchange heat pumps make sense. The original poster mentioned he is in the Northeast, as I do. Air exchange heat pumps are just very expensive electric heaters up here ;-)
Geothermal works, jury seems to be out regarding lifetime costs of ownership and operation. Installation costs of geothermal are very high com paired to air exchange units.
Just think there you might have missed the location - Northeast.
gerry
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gerry wrote:

Gerry and Turtle, Thanks for your input. I think my builders goal here is to use 2 zone heat for the main house (2600 SQFT colonial) with a 2 zone forced air oil system, and since (I guess) the run length is too long for the office (room over mudroom) and family room (room over garage) which is about 420 SQFT total to use a heat pump to serve that area. He is supposed to call me today to discuss this further, I'd just need a heads up on the pros/cons/options available. Again thanks.
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This is Turtle.
I was reading Gerry's replys and you do live were it does get cold and the Heat Pump would not be a very good replacement for a Oil or Gas fire furnace. Go first Oil / Gas then last Heat Pump. Heat Pumps are good but in heavy use / cold ass weather oil or gas will out do them heat pumps in cost to operate and heat faster.
TURTLE
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Since natrual gas at this time does not follow oil pricing changes as much, would it not make more sense today to go natural gas than oil fired ?
MC

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This is Turtle.
This is a local issue and the only [ More Senciable fuel choice ] good choice would be look at the local cost per BTU of oil -- natural gas --- Propane --- Electricity and see which is best in your area.
Here in Louisiana Natural gas is the best choice for we here produce about 20% of the natural gas the United States uses. Natural gas is Cheapest cost and Electricity is the highest cost. Other states will be a different story all together.
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[original post is likely clipped to save bandwidth]

Natural gas very much LEADS oil prices in markets such as Boston! The problem is delivery. The pipeline can't handle it and, particularly since 9/11, LNG delivery via tanker has limited capacity.
In Eastern MA, they even supplement NG with air-propane mix in the NG mains at peak winter demand. That drives up propane and "pseudo NG" prices.
gerry

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This is Turtle.
Is that North of Mississippi ?
I'm not versed in cold weather for here +40F is frost bite weather and Warm is 100F+ .
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Maybe where you're located, Turtle. But up here the contractors charge the homeowners based on what the homeowner think's s/he's getting, not what the products cost to purchase.
Also, central a/c is somewhat common though in most localities, hardly necessary and therefore, not as expensive to install (especially in new construction) as it would be down South or in the MidWest where they're as necessary as our baseboard heating systems, if not more so.
Add a heat pump to this mix, however, and the contractors realize a substantial savings. They talk homeowners into them because for little more than the basic cost of a basic central a/c system, the contractor has also provided heat w/o running a single pipe for baseboards. And not having to provide a triple wall, double insulated stainless steel flue along with a roof penetration, to a contractor, is just golden.

None of which concerns the homeowner, because as a businessman, time saved is money in the contractor's pocket.
The OP is finishing space that otherwise wasn't planned for in the heat/a/c load calculations. Or maybe, so the contractor says. What the heck, if the contractor can get the owner to spring for a totally unnecessary 3rd heatpump package, complete, well that's just icing on the cake.

I do know about it. All about it. And I think I'm more in tune to how contractors and homebuilders operate in the Northeast. Do you know how a homeowner can tell his builder is lying? His lips are moving.
I'll bet the homeowner was also told he heeds a bigger electrical service for that additional heatpump as well. Not to mention all that extra power and lighting a bonus room/den will need.

If you forget everything I've said, fine, but remember this:
In the Northeast, unless you have cheap hydropower (which effectively puts you so far north as to make a heatpump virtually useless anyway) natural gas provided by a regulated utility, or an oil burner fueled by oil companies who are in direct competition with regulated gas utilities, is ALWAYS CHEAPER for heating a home.

I don't care whether you react or not. The OP was more about the necessity of another zone on a still undescribed system, although it was suggested to the OP by the contractor that the additional space be on it's own heatpump system.
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[original post is likely clipped to save bandwidth]

In the Northeast, air exchange heap pumps are extremely expensive to operate during heating season. The backup heat (electric?) will be doing most of the job for heat. So you get and expensive air conditioner and expensive heat.
Geothermal heat pumps might be energy efficient but total lifetime costs seem to be up for debate. A lot of equipment to maintain and expensive ground exchanger to install.
Will two zones work? There are well established design guides any heating contractor should have used. Ask for the calculations.
If this is a forced air system, by far the most common problem in the northeast is poor return design. Particularly upper floors overheating in summer. Each room that might have a door closed needs a proper return. Somehow the zoning must accommodate seasonal changeovers as well.
gerry
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Just thinking about this you have a few options and maybe a dilemma or two to face. Who designed the building? Who specified the type of heat and number of zones?
Let's say you determine the builder to be at fault and refuse to pay him any additional. How good of a job do you think the rest of the house is going to get if he just lost a couple of grand on the heating system? I doubt he is going to take a big hit, smile, and give you the first class job you are paying for. That money has to come from someplace and one way or another, it probably will be you.
Sit down with the builder and the mechanical contractor. Get their ideas, and more important, the actual reasoning behind the decision to change. If the guy is good, he will give you sound advice based on his experience and knowledge. You surely don't want a new house with deficiencies in the heat or the economy of running the heat. If you don't feel comfortable with the decision, talk to another mechanical contractor. Either way, it is much easier and cheaper to fix any problems now rather than after next winter. Ed
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It sounds like these "extra" 2 rooms over the garage/mud room are what are known as "bonus rooms" which sometimes, future finishing, or finishing from the onset aren't taken into account when planning/sizing the original HVAC system.
Regardless of how efficient the original heat pump is, in the Northeast they're just not the way to go for the long haul. They save the builder tons of money because they get to sell the homeowner both a central a/c AND heat for little more than the cost of central a/c only. The homeowner is then stuck paying for this folley for all of eternity, while the builder and electric company (who often subsidize the builder under the guise of installing an "energy efficient" system) laugh all the way to the bank.
If you have a gas main in the street, go with gas heat, or at least get the gas to the house for cooking / hot water / clothes drying. (Much less expensive than electric) If not, go with an oil burner for heat.
Do not let the builder sucker you into installing 2 or 3 heat pumps. A heatpump in the northeast is about as useful as a swamp cooler in Antartica.
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Edwin Pawlowski wrote:

Edwin, Can you explain the difference between two and three zone heat? Does that mean a bigger furnace and an extra thermostat, or something more costly and complex? Thanks.
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Thermostat is the cheapest part of the job. You have to have separate distribution of the heat to each zone. That means different piping or ducting.
As for the furnace size, it would be the same. When deciding how large a heater, the building is gone over, room by room, to determine the needs. You take into account the type of construction, the amount of insulation, exposure, roof type, expected minimum or maximum temperatures in the climate. Adding it all up gives the total size needed. You can go with one large or two smaller units to get the same effect.
Not seeing the layout of the house it is not possible to give a definite answer. If the rooms in question are distant, it may be difficult to get the heat from the heater to the rooms. There are losses along the way. If the rooms are such that they need more heating that other parts of the house, it is not efficient to fire up a large heater to do just two rooms. It may be more economical to have a smaller supplemental unit. Only way to decide is to see the actual house plans and work from there.
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[original post is likely clipped to save bandwidth]

Not Edwin here
A zone is just a area of the house with independent controls (and sometimes equipment) and can restrict supply of heating/cooling to that area. An extreme case might be each room has its own zone, own thermostat, own duct dampers if forced air or circulator/valves if hydronic heat. A zone can even have a completely in dependant system.
Forced air systems are much more complex to zone than hydronic systems. Hydronic furnaces tolerate variable loads very well, often even include domestic hot water. This is because the furnace often has a thermostat to control it's water temperature, zone controls merely turns on circulation. Of course, this is a heat only setup/
Forced air systems have significant problems with heavy zoning. Both AC units and forced air heat systems don't take kindly to variable loads (different number of zones calling at a time) without more complex variable output designs. Traditional forced air equipment just doesn't handle variable air flow or loads well.
So zoning is just partitioning off areas with separate controls, maybe separate equipment.
Back to heat pumps: Common air exchange heat pumps are a total disaster in the northeast. Air exchange heat pumps don't work well (or at all) as one nears freezing. The cheap way out (installation) is electric backup. $$$ I know of some geothermal installations west of Albany NY, not clear if their lifetime costs will prove effective.
gerry
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