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.

 

[tractortroof]

I wouldn’t let him dictate the ac contractor when the price wasn’t agreed upon in the beginning. I’m an hvac contractor for 20 years. In Florida we don’t use Trane because their coils are failure prone. I have a 4 ton 2 stage system in my 4100 sq ft home. Contractors generally put in 500 sq ft per ton because many crazy homeowners want the system to cool to 68 in 1 hour from 85. 500 sq ft per ton will do that.

How you build the home is more important than seer. Where do they still let you install 10 SEER? That’s been gone since 2005 around here. Minimum is 14 these days, they don’t even make 10 SEER anymore

 

[JLY]

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.

Years ago when I replaced my conventional heat pump I was down to geothermal or propane for a 2600 sqft house in SW Ohio. I found an ask the expert on the Energy Dept. website and his comments were that Bothe provided equivalent heat performance but that propane prices tended to peak during the winter when the tank needed to be refilled. Electric rates tend to be steady all year. My contractor sized the geothermal system to work down to 5 degrees air temp and then go to backup electric resistance heat which rarely comes on. You can even get some hot water from the system. The compressor is in the basement so no ugly box outside and I can barely hear it standing a few feet away. There are several SEER values available so remember this will be in use for 20 yrs so I suggest going for the highest SEER you can get. Also go for the closed loop rather than open loop system since open loop can be subject to contamination and need regular maintenance. I have a 2 speed compressor and variable speed fan which I run year round to circulate the air. I use 2 inch MERV 11-13 filters that I get on line. There may even be a tax credit up to 30% available. Be sure the tax credit paperwork is made out to you, not the contractor.

 

[RookieWelder]

I have an opinion about geothermal HVAC systems that may not be popular, but it is based on owning 2 homes over the years with geothermal heating and cooling. My experiences are both with open-loop geothermal, so maybe folks with a closed loop system have had different experiences...

I don't see myself having a 3rd home with geothermal HVAC. Although it is absolutely true that geothermal is, by far, the most economical way to heat or cool a house from an operations perspective, there are downsides to geothermal that folks generally never mention.

1) The up-front cost is very high. Even with Federal and State tax incentives, geothermal is still expensive. Best case is that the tax incentives bring the installed cost into the same realm as a conventional heating/cooling system. And remember, these are TAX incentives -- typically, you still have to pony up the cash upfront and then get it back later through reduced Federal and State income taxes.

2) While this is true for all kinds of HVAC, you really REALLY need to make sure that the company you are using understands how to install geothermal properly. These are very sophisticated systems and a mistake in installation can cause you a lot of pain and suffering, and they can take a long time to identify and correct.

3) Geothermal systems require far less maintenance than traditional HVAC systems, but they do require some maintenance and occasionally repair. Not every HVAC company is well-versed in the ins-and-outs of geothermal. This reduces your options in the event that you have a falling out with the installing company, or in the event that company goes out of business, or if you need an emergency service in the middle of the winter. It does force the homeowner into being something of an expert in geothermal systems so that you can make an emergency repair on your own, or do some regular maintenance to save a few bucks.

4) Any very high efficiency equipment is going to be sophisticated. This almost always means that cost of replacement parts may shock you. As an example, I have a Florida Heat Pump split unit. The fan motor failed in the air handler. The cost of the new fan motor was $1600. I thought I was being lied to, so I called a number of other HVAC outfits. Two of them did not work on geothermal units (see my point above), but they told me that I was being robbed because a new fan motor was about $800 installed. A third outfit that did work on geothermal regularly told me that since Bosch had bought Florida Heat Pump, the prices on parts had gone up some and that the variable speed fan motor in my air handler was indeed a $1600 part. That $1800 repair ($1600 parts, $200 labor) ate up a LOT of the energy savings that the geothermal unit had brought me over the years.

5) This applies to open-loop geothermal, and likely isn't an issue for closed loop systems. The first home I owned with geothermal HVAC used a single well for supply, return and domestic water. It took the better part of a full winter to identify the proper height at which to hang the pump such that I would not suffer thermal mixing or freezing of the return water. This was a painful experience. My current home has a dedicated return well. This has eliminated that issue, but there are others. Water quality becomes a huge concern with open-loop geothermal. When my current supply well suddenly began producing large amounts of particulate matter at year 5 of geothermal use, I found myself struggling to find a proper filtration solution that wouldn't have me cleaning the filter daily. One must also have a properly sized and installed water pumping solution. I ultimately went with a constant pressure pump and a small pressure tank to limit the number of starts and stops that the pump would otherwise encounter when supplying a geothermal heat pump.

Anyway, these are just a few of the less-positive aspects of geothermal heat pump ownership. There is a lot to be said for a conventional HVAC system...

 

[priberc]

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

IF I was you....I would be looking at geo thermal and heat pumps for your heating/cooling system. Stay away from any form of fossil fuel dependancy that you can. For example propane has doubled in price in the last twenty years with a spike to triple. Food for thought

 

[Hotpot]

I had a cousin who was dating a guy in college for havc. He came over and did all the calculations for the house i was rebuilding and when we talked he said return air was the just about as important as anything. i built the system the way he designed it. A pain in the ass to get all the return air to each room but man does that system work good, very low energy bills. Compare that to the system i paided a contractor to install in another home i had, a few years earlier. The contractor only put in two return air. Every renter in that home has complained about that system and how it does not work well. So.... my advice is return air, return air,return air, from every room.

 

[Rustyiron]

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.

Entire home? I'd say yes providing that just like a ducted system, rough in needs to be done just after framing for the best flexibility. Each individual room unit has a line set and condensate drain.

 

[workinonit]

I just can't see that. My house would have to have at least 6 units to take care of air flow. I don't even know how you would do that. Bathrooms, laundry room, closets, hallways. Color me stupid but I just don't get it. I'm going to add a sun room and will likely use 2 of them there, which I think is a perfect application for one or two but give me ductwork for the bulk of my house.

 

[ironhardware.com]

It’s interesting that I see no mention of hydronic heat in this thread. Is it not used in those areas? Very popular in snow country. Doesn’t provide much cooling unless your incoming water temps are pretty low in the summer, but it sure is efficient, quiet, and cozy during our extreme winters on the central coast of California . No blower kicking on and off all night drying out the air, and everything in the home is consistently warm to the touch. We install pex tubing in every slab we pour.

 

[rv7charlie]

we don’t use Trane because their coils are failure prone

Please don't say that loud enough for my systems to hear you. ;-) I think they were about 3 or 4 years old when we bought the house, had it cut in 3 pieces and moved about 25 miles to a new location (paid someone with freon tools/experience to pump them down & reconnect/recharge at the new location). That was in 1997. It would be nice to upgrade to a higher SEER rating, but they just won't die; or at least won't die dead enough that I can't fix them. I've replaced the control boards in both furnace/air handlers (within the last 5 years or so), an air pressure sensor in one air handler (not sure that one wasn't the control board), and a capacitor, the fan, and the crankcase heater in one compressor. These failures were scattered across more than a decade, and I did all the troubleshooting and repairs, with a bit of help from the interwebs. If I'd been paying an HVAC contractor, I suppose I might have been more motivated to install new hardware by now, but as long as the rare and random repair costs stay well under $100, it's difficult to spring for new systems.

 

[fishdrivel]

I've built 8 new houses in my life. I've always used "the best" option for HVAC. Never go on the cheap.

Based on the options your builder has given you, I'd seek out another quote on your own from another HVAC contractor. Carrier or Trane are both good systems. 15 seer is lower than I would go. They make equipment up to 20 seer now. Higher the seer the more efficient it is. I have 17 seer. Very efficient and low utility bills. And with you being on propane, the more efficient the better.

Also, you should be able to get a "zoned" system. One AC condensor, one furnace with 2 zones of ductwork. It's what I have in my home now. Works great. Separate thermostats for each zone. Costs a little more for ductwork installation, but lowers the overall costs on 2 condensors and furnaces.

And putting both return ducts 7' apart is mal-practice IMO. I'd never put them that close together. Contractor is trying to make it easy on himself (jeeze...there's a surprise).

And remind your builder whose house it is, and who is paying the bills. If you're not satisfied with his HVAC contractor he can easily find another for you. He just doesn't want to.

Very good post. I'm not liking the sound of this contractor. 15 seer in legal in new home - but is it desireable?
A 3200 square foot home is not a cheap home - why put a minimum quality system in?

I had a zoned system in California. Without it, the house would have been hot in the Am on one side and hot on the other side in the afternoon.