Building a custom home - HVAC options - could use a bit of help please!

[ameliasolis]

Hi!

We are in the process of building a 3200 square foot custom home in North Carolina. We have been approached by the HVAC contractor and given three options for the systems we can choose (he has estimated a 2.5-ton system upstairs and a 3.5-ton system downstairs). They are all Trane systems and are:

Option #1: The XB1000 air conditioner (10 SEER) with the XE80 gas furnace for approximately $12,000***OR***
Option #2: The XR12 air conditioner (up to 13 SEER) with the XR90 gas furnace for approximately $15,000***OR***
Option #3: The XL14i air conditioner (up to 15 SEER)with the SV90 gas furnace for approximately $18,800.

Our questions are:

1. In light of the upcoming regulation changes, what would be the minimum expected requirement for a custom home?

2. What are the real differences in comfort one might feel in the different systems (I am more sensitive to heat and humidity versus cold)?

3. We are not on a gas line, therefore, we will be on propane, and option #3 includes a two-stage gas furnace. What kind of savings can we expect to see with a two-stage system?

4. We have a fairly open floor plan; however, there were no designed-in locations for the return ducts. Our contractor has proposed two locations within 7 feet of each other (no barrier walls involved) for the first floor. Will this be sufficient to adequately draw air?

5. He has also presented the option of an electronic air cleaner at a cost of $1495 - are these worth that expense? Do they really help with dust?

Our general contractor has not offered the option of getting other "bids" to verify fair pricing and the HVAC company is ready to start working now. Any help, advice or guidance offered would be most appreciated.

Thanks!

 

[e hilton]

Can you even install a system with seer 10 now?

Ask the hvac contractor if he has run a Manual J calculation, make him show it to you. I don’t like the part “he has estimated”

 

[ICE]

A higher SEER ratio equates to less expensive to operate. Here in California, 14 SEER is the minimum. The difference between an 80% efficient and a 90% efficient furnace is the venting. The 80% will have a B-vent whereas the 90% is a condensing type with a PVC vent. Obviously there will be an operation cost advantage with 90% but I don't know how much.

 

[Msradell]

I'm not even sure you can buy Option 1 because of the low efficiency of the AC but if you can you don't want it anyway. I personally would go for Option 3 since it will give you better long-term savings.

 

[north star]

# ~ # ~ #

Welcome ** ameliasolis ** to the Building Code Forum !

(1) You should definitely request the Manual J calculations,
"IF" the contractor can provide them.........If not, then find
another reputable contractor..........Please do not be shy or
hesitant about requesting the calculations.......You should
be able to easily understand what you are buying before
you buy it !

(2) What type of written warranty is associated with each
system ?........Parts & labor are one thing, the compressors
on each should be a long term warranty........After the
initial installation, If you need service on one or both of
the units, does the HVAC contractor offer after hours,
weekends, holidays, or inclement weather servicing ?

(3) I agree with the other esteemed Forum contributors,
you will want the higher SEER rating in both units.

(4) Ask what type of freon will be used in the units.....In
my area of the world, the R410A is the most current.

(5) Regarding other HVAC contractors, IMO, ...you
should definitely shop around and get other prices......Just
because the current contractor "is ready to start now"
doesn't mean anything.......I strongly recommend that you
do not rush in to anything, and do not sign anything
until everything makes financial & working sense to you.

(6) Regarding the two Return Air locations, if your Supply
Air Grills will be in the ceiling areas, then your Return Air
Grills should be located down lower towards the floor.
This will provide more air circulation.......Are either of the
two Return Air Grills located near the Kitchen Area ?
I would not be in favor of having the Return Air Grills
located that close to each other, but rather, much,
much farther apart.........** ALL ** parts of each HVAC
System should be legibly drawn on to large plan sheets,
including the sizes, dimensions and locations.

(7) In my area of the country we have a lot of pollen,
dust, grasses, mold spores, and on and on and on.
I would NOT be in favor of adding an "electronic air
cleaner" at the initial installation.........If conditions in
your locations are bad enough for an electronic air
cleaner; and some areas are, ...then you can retro-fit
later on, or buy a "stand alone unit"......I would NOT
pursue this option initially !

(8) I recommend that you have a good notebook or
two and take good records, of all meetings, dates,
times, and of things spoken, but not necessarily offered
in writing.........This New house of yours is a very large
investment...........It is your money, spend it carefully &
wisely !

Please DO come back on this Forum and let us know
how things turn out !

# ~ # ~ #

 

[Paul Sweet]

Propane costs as much to operate as electric resistance heat. I'd recommend heat pumps instead of air conditioners, so the heat pump can heat the house most of the year and the propane furnace will only be needed on colder days (below 30 or so).

6 tons total seems like a lot of cooling for 3200 SF under the current energy code, unless there is a lot of solar gain.

I've been using Aprilaire filters for my house. They take a 4" thick folded paper element which only needs to be changed once a year and is available at Lowes or Home Depot.

Whole-House Air Purifiers

Aprilaire's suite of whole-house air purifiers and portable air purifiers capture allergy and asthma triggers like mold, pollen, dander, and dust.

www.aprilaire.com

 

[my250r11]

Some of these questions can be answered by manufactured with a phone call.

 

[ameliasolis]

Can you even install a system with seer 10 now?

Ask the hvac contractor if he has run a Manual J calculation, make him show it to you. I don’t like the part “he has estimated”

yes. I installed it already.

 

[ameliasolis]

A higher SEER ratio equates to less expensive to operate. Here in California, 14 SEER is the minimum. The difference between an 80% efficient and a 90% efficient furnace is the venting. The 80% will have a B-vent whereas the 90% is a condensing type with a PVC vent. NYC Scaffolding Obviously there will be an operation cost advantage with 90% but I don't know how much.

thank you so much for your suggestions.

 

[Mr. Inspector]

You may want a geothermal system. Expensive to install but very inexpensive to use.