HVAC Heating Zone question

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.

Reply to
TN
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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.

Reply to
HA HA Budys Here

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.

Reply to
Edwin Pawlowski

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

Reply to
TURTLE

I'm the resident troll?

Reply to
HA HA Budys Here

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

Reply to
gerry

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

Reply to
Edwin Pawlowski

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.

Reply to
HA HA Budys Here

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.

Reply to
TN

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.

Reply to
Edwin Pawlowski

We use heat pumps in the midwest where its plenty cold, mine is a 3 ton,16 seer and heats a 1600sq ft ranch main level and 700 down stairs, holds 69 degs, when the outside temp is 17degs.

Tom

Reply to
twfsa

What's your Kwh rate? In the NE it can be as high as .18 per Kwh. How often do your backup elements come on, and how often does the unit go into defrost mode?

Heatpumps in the Northeast are only used because builders are cheap, want the cheapest heating/cooling plant, and don't want the "hassle" of providing things like fuel storage, chimneys, or natural gas. In addition, the inside air handler can be located just about anywhere.

Reply to
HA HA Budys Here

This can easily be done using one furnace with one air conditioner (and if needed, a 2 to 3 zone zoning system).

I assume you are speaking of a natural gas fired furnace, and using an electric air conditioner.

Technology today is more advancede and because of that, easier to manage home comfort.

This is what I wold use in your situation. A 96% AFUE gas furnace with a variable speed fan system. An 18 SEER 2-speed electric air conditioner, (yes, with TXV on evaporator) A Thermostat that not only controls desired heating and cooling comfort levels, but controls humidity levels in the home as well. (dehumidifies via the A/C as well as operates an add-on humidifier)

If the furnace is to be located at one end of the basement, and you have difficulty with airflow to a room over the garage at the other (far) end, you may want to split those difficult areas into "zones" If so, an effective way to do so is using Arzel Zoning Technology.

I would get another opinion from a contractor who is experienced in zoning needs.

Someone who knows how to correctly calculate the required heating and cooling loads in your home, understands how to size the ductwork required to move the air which will carry those loads, and if need be split the system into zones - all using one furnace and one airconditioner.

Just last month, I removed 2 furnaces, and 2 airconditioners from a building (beauty solon) installed one furnace, one air conditioner, and an Arzel AirBoss 3-zone panel. We used 3 programable thermostats using the existing ductwork and improved the "irregular heating/cooling" in the various parts of the structure, while saving the customer $$$ on their monthly fuel consumption. The furnace was a 96% 120K-BTU 2-stage heat, with a 5-ton single-speed air conditioner, a Thermidistat in the "main zone" and 2 standard programable thermostats for the other two zones. we also properly sized the required fresh air intake into the system for the needs of the business (in acordance with local codes).

Here is the equipment I would reccomend, if I were speaking to you "person to person."

Air Conditioner:

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Furnace:
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System:
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Thermostat:
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Read the brochure:
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Zoning:
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Want help? Call a Factory Authorized Dealer in your area:
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good luck!

Reply to
Gate

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

Reply to
TURTLE

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

Reply to
gerry

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

Reply to
gerry

At 17 F your "heat pump" is just an electric heater. Most likely you are describing an air exchange system with electric backup heating strips. In the Northeast, where the original poster is located, electric heat is generally very expensive to operate.

gerry

Reply to
gerry

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It is fairly unlikely the A/C does a very good job at dehumidifying. High SEER units tend to be poor at latent heat removal.

And I would research costs associated with captive designs (proprietary repair parts) with Carrier and a few other big names.

I am not suggesting they are not good units, just lifetime cost of ownership (repairs and service) tend to be higher with some brand name equipment.

Thus, add the cost of a long term service contract when getting quotes.

gerry

Reply to
gerry

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.

Reply to
TN

Thanks, your explanation is better than mine. Ed

Reply to
Edwin Pawlowski

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