Heating cooling HVAC Help needed

hunterdan

hunterdan

Well-Known Member
Joined
Apr 13, 2009
Location
Morganton,NC
I'm in the middle of building a home and it's time to do HVAC,plumbing and electrical. As far as the HVAC I'm just looking for advice about best type,size unit for this home.

Home is 28x28 single floor with a 28x28 walkout basement.
Combined (ACTUAL living space is 1420 sq. ft.)
Home is simple floor plan with one dividing wall downstairs and one on main floor.
Trusses in basement are engineered and have built in flue chases ...one on each side of and parallel to dividing wall.
Main floor has vaulted ceiling in living room at 18'

I talked to one guy that advised a mini split but I will have to install flue chases for code anyway

Another HVAC guy said I would need a heat pump on bottom floor and mini upstairs...

Lastly, another said a 3.5 ton would work.

Any advice appreciated.

There are some good pics of home and layout under thread "House build start to finish"

House build start to finish

Dan
 
nice house
Is this going to be an all electric house? any LP or natural gas available? what are your thoughts on heating?
a 3.5 ton unit would be sized correctly for the house of that size. a split system might give you a little more control/comfort of the temperature throughout the house and it would leave you with a cooling if one of the units were to have an issue.
 
If gas/lp is an option for you,

I would do a 99% high efficiency gas tanked water heater with a few baseboard heat exchangers and a circulator pump. Couple that with a heat exchanger for the duct system. You can valve off what you want to use and when. The heat pump would only be for additional load and for the cooling season.

Second choice would be gas furnace.

Third would all electric.
 
I have a mini split in my shop. It is a Mr Slim, came highly recommended by my HVAC installer. I'll never buy another one. Works ok in a large open area but upfront costs are high and when it breaks, parts are ridiculously expensive. Way too many electronics in them.

Where you are, you might want gas for heat, unless you have a fireplace.
 
Thanks for the info. and the compliment. I talked to another fella today who said a 3 ton unit would do well for 1450-1700 sq ft. Says 3.5 might be too big and not remove humidity as well... Upstairs we have a wood burning FP so heat is not a problem combined with a heat pump. Downstairs we figured would also be heated/cooled by the HP and a couple ceramic heaters in the kids rooms if needed. Maybe a de-humidifier in the basement?
As far as gas my wife is scared of gas fixtures...
 
We have a 4 ton unit for a house twice that size. 3.5 sounds too big.

If it were me, I'd want separate zones for each floor.
 
with the walk out basement and FP for heat. a single unit would make the most sense. A humidifier/De-humidifier installed in the duct work, would help humidify the house in the winter with just the fan running to offset the dry air from the FP. and in the summer it could De-humidifiy.
Mac5005 has a good point with the Heat re-claimers just pair it with the FP.
 
Anyone have opinions about geothermal heat pump?

also looking at using dryer to aid heating basement. With two kids we are constantly washing/drying clothes. During winter we could dehumidify and filter the dryer heated air and with a valve switch to outside vent in summer.
 
When I built my house 28 years ago I calculated the heat gain (cooling load) and hear loss (heating load) for each room. Exterior wall,ceiling,and flloor areas were considered including their R values and window and door openings. Even their compass direction was considered. Add all the rooms together for a total. This is the size of the unit required. This also guides the duct size required for each room. If the equipment is sized properly additional humidity control should not be needed and temperatures will be even through out the house. You can also experiment will different insulations and windows to see how they effect the total loads
 
moldman05 said:
When I built my house 28 years ago I calculated the heat gain (cooling load) and hear loss (heating load) for each room. Exterior wall,ceiling,and flloor areas were considered including their R values and window and door openings. Even their compass direction was considered. Add all the rooms together for a total. This is the size of the unit required. This also guides the duct size required for each room. If the equipment is sized properly additional humidity control should not be needed and temperatures will be even through out the house. You can also experiment will different insulations and windows to see how they effect the total loads
Click to expand...


This is the only way to do it right. Anything else is just a guess. Pay someone to run a room by room load on the house. Like said above Depending on what windows, insulation r values, or even the direction the home faces play a large role in the hvac load of a home. Sizing on Simply square footage leaves a lot of room for error. Oversizing a system has its own set of problem. High humidity in home, unit short cycling, increased power consumption, extra wear and tear on components from the staring and stoping often.
 
hunterdan said:
Anyone have opinions about geothermal heat pump?

also looking at using dryer to aid heating basement. With two kids we are constantly washing/drying clothes. During winter we could dehumidify and filter the dryer heated air and with a valve switch to outside vent in summer.
Click to expand...
Any geothermal input would be great. I'm in the planning stages of a house right now and I think I'd like to go geothermal if I could find a reputal installer
 
Geothermal is very expensive to install. A few years back there were excellent tax credits that helped the payback period to be reasonable. I think those tax credits are gone or greatly reduced now.

If I was building, geothermal would not cross my mind.
 
I looked into geothermal when I started our plans....payback just wasn't there. About break-even over the 20-25 years we'll be in this house. And thats even factoring in replacing the heat pump every 12+ years or so, at future inflation-adjusted prices. The geo stuff has a much longer life (and more expensive repair parts, too).

Heat pumps are so much more efficient now than 15 years ago when our original went in, that we replaced 2 years ago. And the heat pump that I use replace the one going into the new house this year, will be even more efficient than the one I am buying now.
 
From what I understand a lot of the upfront cost of geo is installing the loop. I have a good grading guy and could put the loop in myself with his help in a day from what I've read.

Anyone have knowledge of the actual unit/associated cost?
 
from what I read about geothermal units and what got my attention;
!)They are long lasting and have little if any maintenance
2)They use 30-60% less pwr
3)about as noisy as a fridge
4) Have/Had a 30% rebate from the Gov which makes them slightly more than a regular heat pump.
Good link describing geothermal
http://www.geoofthecarolinas.com/Geothermal-North-Carolina/why-geothermal/how-geothermal-works

The main cost is burying the coils. They can be done horizontally,vertically and even installed in a pond or lake if 10' deep. The pond/lake method is the cheapest but I don't have a pond. I do however have an ice cold river....Hmmmm?
I think I read that the coils have to be about 6' deep and 2' wide for the horizontal method similar to a septic system. The vertical style is 100-400 ' deep shaft 4" wide. A lot depends on what soil,region and how deep to find a constant 55 degrees. Again that makes me think about the river.


In the end we will probably go with a heat pump after getting it properly figured regarding windows/load...
I just hate heat pumps and have been done wrong by many a heat pump tech. Either you pay an honest one 500 for a 200 job or pay a liar 300 for a 200 job but he steals a part off yours for another job:) or cases your home.

Really though we've had a pump go bad and replaced with new at 3-4 past homes

*****I don't want to pay for the Trane price. Anyone suggest a brand other than Goodman that is reputable???
 
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river levels drop during the winter and droughts. if the river is deep enough to float a kayak then it is considered a navigable river in NC. Also property lines typically go to the center line of waterways. unless you own both sides of the waterway.
 
This river is year round and I own both sides with no nearby neighbors. But...I believe it would need to be a backwater area if using a river due to heavy current after heavy rainfall,branches floating downstream...

In the end I'll be looking at heat pumps but could use direction regarding brand.
 
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I am doing Trane, but only because I have known the guy that owns the hvac company since I was about 3' tall. He does me right. Last time my system was dead, it was only $75 to replace the cap. I would have done it, but it was pouring rain that day.....i will pay someone else to get electrocuted on my behalf.

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kaiser715 said:
I am doing Trane, but only because I have known the guy that owns the hvac company since I was about 3' tall. He does me right. Last time my system was dead, it was only $75 to replace the cap. I would have done it, but it was pouring rain that day.....i will pay someone else to get electrocuted on my behalf. QUOTE]
Click to expand...

OK thanks, anyone have experience with Rheem or Carrier heat pump?
 
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