Zoning or Dual System

[robertc65]

I have noticed that many new houses being built in my area are getting a gas unit installed in the basement for the 1st floor and a heatpump in the attic for the second floor. It has been my experience that builders will install options that maximize profit vs what is best for the homeowner. Can a single larger gas system using zoning do as good or better than a dual system. I have had a heatpump in my last two houses and have never been comfortable in the winter. I simply don't want a heatpump.

I know that many people say a properly installed heatpump can be just as good as a gas furnace but I don't agree with them. I live in the Baltimore area where it often gets down to below 10 degrees. I just find the gas heat more comfortable.

I am planning a new system in my house which is 3000 square feet and 3 levels. I want the most comfortable system I can get not necessarily the most cost effective. I am willing to pay $20 or $30 extra / month to be comfortable if thats what it takes.

Thanks
Rob

[robertc65]

I know you guys do this for fun and don't owe me anything, but did I say something to turn you off from answering my question. I know I stated a strong opinion regarding heat pumps but I'm really not very hard headed and can convinced otherwise with a good argument.

Thanks

Rob

[nathan9999]

Rob, in my experience on the forum (I'm not a HVAC pro) the responses have an ebb and flow based on how busy the participants are and if they feel they have something worthwhile to add to the discussion.

You might try posting the same question on a Saturday morning, for example, and see if you get a better response.

You might also do a search on "zoning" and read some of the previous discussions.

Hope this helps.

[dash]

Properly designed and installed ,I'd rather have zoning then two systems.You can get 4 or more zones that way,so more stats ,and more comfort and control.

Carriers Infinity zoning is tops,IMHO.

Gas furnaces versus heat pumps,doesn't matter to me which you prefer.

I'd probably say go dual fuel,heat pump down to where you like the discharge air temp., when colder it runs the gas furnace.

[wyounger]

Dual fuel is certainly a good choice. The operating cost advantage is still there, but in subfreezing weather, you fall back to gas heat instead of electric.

I stand fast in my assertion that anybody who doesn't like heat pumps has only experienced old, poorly configured, and/or low-end setups using old-fashioned control systems. When done really right, heat pumps are pretty much indistinguishable from gas heat. I'm a winter wimp (grew up in southern California, then moved to TN and GA) and I would pick between a nice furnace and a nice heat pump based on the local operating cost of each. My current place is dual fuel, and my neighbors are jealous of my energy bills. It runs the heat pump down to 30-35 degrees outside, then switches over to gas heat.

You're seeing a lot of gas downstairs, heat pump upstairs setups because of the difference in how much heat each floor needs. Once you're already heating the first floor, it takes very little to heat the second floor. It can be hard to get a furnace small enough to do that second floor job well while still having enough blower capacity to meet the big air conditioning needs of a second floor. I myself lived in a house with that problem in Tennessee; the furnace never ran for more than four minutes at a stretch, even in the coldest weather. You were cold by the time it started up, and two minutes later, you wished it would hurry up and shut off again, because you were roasting.

A heat pump in that same application would have been much more controllable, cheaper to run, and probably would have lasted longer than that furnace, too.

Good zoning is great stuff. Infinity zoning is amazing. In your shoes, I'd go with one nice system and a nice zone control setup before taking the same money and getting multiple systems. The only way to get temperatures as even in a three story house without using zoning is with three complete systems, which will cost a pretty penny more to yield comparable results. If it were just two stories, then two systems versus one zoned system is a closer race... but the economics of three systems for 3000 sq feet over three floors just don't work in your favor... especially if you want some bells and whistles for each system, like humidity control and good filtration.

If I were you, I'd build it with Infinity zoning, one furnace, and one two speed heat pump. Then if you need a humidifier, ERV/HRV, UV lights, fancy filtration, etc., you need one, not a set of three. It would be an absolute top of the line system with top of the line results, and probably would cost less than three low-end systems.

[Edited by wyounger on 07-28-2005 at 01:42 PM]

[robertc65]

Thanks for the advise. I'm going with zoning.

[arc8]

Wait. what if you need more than 5 ton of cooling?
two units might work out better!
just a thought to throw in at you.

Heat pump rules!

[m kilgore]

I have a zone system in my house and wouldn't change it for anything. First zone is for the basement and first floor and second zone for the second floor. Have great temp control and no problems in 8 years.

We have been installing alot of zone systems this year with very positive results. The main thing you have to do is find a company that knows how to install them. Duct and bypass sizing are critical. Many companies in our area talk them down because of lack of understanding. When they do install them they skrew them up.

As for gas heat, I have no problem with that. I didn't see if you said where your from but if thats what your comfortable with go for it. I may suggest a higher efficiency furnace 90%+ with two stage output. When one zone is calling for heat more often than not the furnace will run on low fire and save you in utilities.

Good luck with your new house.

[trane]

If this was my house I would put one system in for the basement and 1st floor with two duct systems and zoned for each floor. I would put another system in for the 2nd floor and it would be a heatpump or electric heat. Doing this saves you from having to make a space available for ducts to go from the basement to the second floor and will give you a backup if one system fails for some reason. It will also alow you to size the 2nd floor system for the load rather than have to bypass air because the load is less than for the lower floors. In most cases I can install a second system in the upper floor for not much more than the cost of adding another zone and running the supply and return ducts to the upstairs and it will be sized for that floor instead of the lower floors.

[dan sw fl]

Originally posted by trane
It will also allow you to size the 2nd floor system for the load rather than have to bypass air because the load is less than for the lower floors.

K.I.S.S.
Keep It Simple, SuperHVACman.

Two systems are preferred
as so eloquently stated by _trane_.

[dash]

3 systems versus zoning:

3 compressors,6 fan motors,6 coils,to buy,maintain,and replace at some point down the road.

If each system is say 4,000 btus larger than needed,due to the next smaller system being too small,then we have a on of oversizing.

Infinity Zoning requires No bypass,and will do an excellant job,along with a two stage compressor,and furnace if it's gas heat.

[trane]

Originally posted by dash
3 systems versus zoning:

3 compressors,6 fan motors,6 coils,to buy,maintain,and replace at some point down the road.

If each system is say 4,000 btus larger than needed,due to the next smaller system being too small,then we have a on of oversizing.

Infinity Zoning requires No bypass,and will do an excellant job,along with a two stage compressor,and furnace if it's gas heat.

My suggestion was for two not three systems and yes you will have more equipment to maintain but the the run time will be split between the systems. One system and it runs everytime and will most likely not last as long as two systems with less run time. In most cases I have a hard time getting duct to the upstairs because the home owner doesn't want to give up any space and when they do, it is usually not in the best place as far as duct layout is concerned.

[trane]

Dash, I think he would be happy with both of our suggestions but I wonder what would you say his chances are of picking a contractor the first time that would install your system correct? I would say there are very few in my area that could install a three zone system without having problems both in sizing and duct design.

[dash]

Originally posted by trane
Dash, I think he would be happy with both of our suggestions but I wonder what would you say his chances are of picking a contractor the first time that would install your system correct? I would say there are very few in my area that could install a three zone system without having problems both in sizing and duct design.

You're probably correct.