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

[workinonit]

So you would advocate using mini splits in a 3200 sq ft home? While I think minis have their place, using them to condition an entire home is not one of them. But that's just my opinion from living and installing HVAC sytems in South Carolina.

 

[LD1]

I find it a bit odd that you subscribed to a tractor forum on christmas day just to ask about an HVAC system? Like logic would say to subscribe to any number of home building or HVAC forums. but in either case.....

The three systems you quoted.....pushing a total of 6-tons for a modern 3200sq ft home in north carolina....all three options will likely heat and cool your home just the same. And likely the ONLY difference you will notice is in the wallet. Because the efficiency ratings are different. The cheaper systems are gonna cost more to run per BTU of heating or cooling you put in your house.

You dont have natural gas...and being in the modest climate of North Carolina I'd avoid Propane at all costs.

Seriously look into GEO. NOW is the time to do it if you have the land. Because your yard is likely already destroyed due to construction. You can get the optional electric strips installed for backup....but if your system is sized right you should never have to use them.

Get one with a desuperheater and plumb it with a buffer tank for even more energy savings. Variable speed Geo or 2-stage is the way I would go

 

[Fxfymn413]

As for returns, I would not build a new house without ducted returns in all bedrooms.

I believe the IEC (International Energy Code) now requires a return in each space.

Your home should have been built to the IEC and as such should not require a large system to operate properly. Included in the IEC is the requirement for much higher insulation levels than were required even a few years ago.

Like others here I'm not impressed with your contractor's quotes and I would seek others.

I use propane as a back up heat for a heat pump on the main floor of our house and when it finally dies I doubt I'll replace it since propane has gotten so expensive and heat pumps have gotten so efficient. Plus I can install solar panels to offset electrical costs if I want to.

If I were doing new construction I'd go with a ground source heat pump using a deep well as the heat/cooling source.

 

[RichNJKubota]

Is it too late to do passive solar heat? House would have to be dsigned from the start for this. We did that 25 years ago and have never missed buying oil, gas or propane. House is all electric with PV panels. Net zero. No energy bills. I thought this would be common these days?

 

[hslogger]

We have installed Mitsubishi mini splits over the last eight years and so far so good. It's all a retrofit but we couldn't be happier. I have not removed our ducted forced air wood furnace, but haven't used it since. We still fire up the Jotul now and then.

I think forced air systems, will be less and less popular in the future.

 

[wjhaudio]

I would look for a second quote and definitely would look at a geothermal system as an option. I'm in Southeastern PA (just above the MD/DE border into PA) and have been using a Waterfurnace geothermal system in a 3500 square foot home we built in 2005. We have a lot of glass in the house with a very open floorplan and it keeps it comfortable in all seasons. cost has been low with a worst case electric bill at about $350.00 over that time. Hot water and oven are electric with propane for clothes drying and cooktop and we use a private well and a pump dosed drip irrigation septic that has an aerator pump that runs constantly as other major electrical loads.

 

[rv7charlie]

SEER Ratings

The quoted SEER numbers seem quite low by today's standards, as others have said. If I could talk my wife into the indoor units hanging on the walls, I'd convert to mini-splits. I really wish the mfgrs would make in-floor mounted indoor units. Regardless of the design choice, I like having two separate systems, just for redundancy. If (when) one dies, you can get at least some relief from the other system until the bad one can be repaired/replaced.

 

[RookieWelder]

SEER Ratings

The quoted SEER numbers seem quite low by today's standards, as others have said. If I could talk my wife into the indoor units hanging on the walls, I'd convert to mini-splits. I really wish the mfgrs would make in-floor mounted indoor units. Regardless of the design choice, I like having two separate systems, just for redundancy. If (when) one dies, you can get at least some relief from the other system until the bad one can be repaired/replaced.

You can get ceiling-mounted cassettes instead of the wall-hung units. But, it does require running the copper lines through the ceiling to get to them. This can be a challenge in a retrofit. There are also low-wall mounted units available.

 

[pacosperson]

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 furnance for approximately $15,000***OR***
Option #3: The XL14i air conditioner (up to 15 SEER)with the SV90 gas furnance for approximately $18,800.

Our questions are:

1. In light of the upcoming regulation changes, what would be the mininum 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 furnance. 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 deisgned-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!

The prices are likely in line, maybe a tad high because it's new construction and therefore easier.
I urge you to BUY your own propane tanks. You can even get special ones that do not require re-inspection. When the propane prices go crazy, and they will, you can go to any supplier if you own your own tanks. The 'spot price' is always better than the price plus tank lease price. Yes, they can gouge you if the propane just about vanishes, but you WILL have heat.
I'm a cautious Yankee. I built a house with baseboard electric, propane furnace with purchased tanks, and wood stove.
Enjoy your new home.

 

[rv7charlie]

You can get ceiling-mounted cassettes instead of the wall-hung units. But, it does require running the copper lines through the ceiling to get to them. This can be a challenge in a retrofit. There are also low-wall mounted units available.

I'm aware, but I have under-floor crawl space I can walk around in, and under floor temps are always more moderate than attic. Attic 140 degree temps in summer, and freezing temps in winter can't be good for HVAC efficiency, even if it's just the freon lines.