New Construction HVAC decisions. Geothermal vs. alternatives with upgraded envelope.

[jk96]

Thanks everyone. So much to digest. I'm still not sold on the up front investment. It also appears it's not recommended to zone individual rooms with the 5 series since it's not variable speed system.

Does anyone have a recommendation on a DIY load calc software?

The 5 series offers a duel speed compressor. As long as your duct is sized correctly you should be able to setup so that it runs in low stage when individual zones are calling and bumps to 2nd stage if all are calling. On their webpage they even show a controller under the 5 series literature with 4 zones. 5 Series 5A11 | WaterFurnace

 

[MGH PA]

The 5 series offers a duel speed compressor. As long as your duct is sized correctly you should be able to setup so that it runs in low stage when individual zones are calling and bumps to 2nd stage if all are calling. On their webpage they even show a controller under the 5 series literature with 4 zones. 5 Series 5A11 | WaterFurnace

Yeah I see that zoning is possible, but most if the contractors said doing individual rooms would most likely produce air noise in a two stage system.

Do you have radiant heat in your basement, btw?

 

[jk96]

Yeah I see that zoning is possible, but most if the contractors said doing individual rooms would most likely produce air noise in a two stage system.

Do you have radiant heat in your basement, btw?

I don't have radiant with our Geo. We had two strikes against radiant. 1st was cost like you suggested and the 2nd was that my wife's feet are always hot so the idea of warm floors didn't appeal to her. Everything is forced air. Basement is on it's own zone. We have a finished basement with projector so we use it a lot for movies.

 

[jk96]

Yeah I see that zoning is possible, but most if the contractors said doing individual rooms would most likely produce air noise in a two stage system.

Do you have radiant heat in your basement, btw?

If the duct is sized correctly for the zone layout I still don't see why they are telling you it will produce too much noise. Maybe they don't want to adjust duct size to properly zone your home? What type of ducting are they running? Ours was all custom built duct, no flex so sizing was a non issue.

 

[MGH PA]

If the duct is sized correctly for the zone layout I still don't see why they are telling you it will produce too much noise. Maybe they don't want to adjust duct size to properly zone your home? What type of ducting are they running? Ours was all custom built duct, no flex so sizing was a non issue.

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Looks great. I suppose I should have asked what type of ducting they were specifying. I get the feeling I'm dealing with a lot of contractors that aren't 100% up to the task of managing and installing such a complex system.

Side note...did you insulate your slab? If so, do you feel the floors are comfortable with just the air heat?

 

[Sigarms]

Looks great.

Great duct work is wrapped, not lined.

First came to NC and everyone tells me they don't use that ductboard crap like they use up north, that they use sheet metal down here. What do they do? Line it. Wow:laughing:

 

[BitChin1]

I assume JK will answer as to his specific situation, but in my house insulated the basement floor with 2" type IX EPS (~ 9.7r) and have had no issues with condensation - we tiled the basement floors as well as our main level - the floors are not "warm" but don't feel any colder then our wood floor in loft area (using IR temp I see the basement floor typically within 1' +/- or the ambient air which we maintain between 64' and 70')
On my next house I will do similar insulation below slab as it is nice not dealing with condensation issues under boxes etc that I experienced in previous house.

 

[jk96]

Great duct work is wrapped, not lined.

First came to NC and everyone tells me they don't use that ductboard crap like they use up north, that they use sheet metal down here. What do they do? Line it. Wow:laughing:

There are pros and cons to both internal lined duct vs externally wrapped but that was not my point in the post about the ductwork. It was to make sure the ops bids are specifying the type of duct used, especially metal vs flex. I've seen some jobs were the contractors ran flex all over the place and not metal. Sags in the flex, restrictions from hanger straps, etc creating a ton of air restriction and loss of performance.

 

[jk96]

Side note...did you insulate your slab? If so, do you feel the floors are comfortable with just the air heat?

I know most building advise says to insulate your slab and probably a good idea but we did not. We sprayed 2" of closed cell on the basement walls, filled all rim joists cavities around the perimeter with closed cell, and fiberglass batt insulation in the ceiling, but skipped the slab. I wanted to take advantage of the ground temps as we use this area most in the summer. We have carpet in the basement so no real worries about the floor feeling cold in winter. We never run air in the basement and rarely use heat. It stays a pretty constant 66-70 degrees year round depending on the season. Our house sits higher than most of the surrounding land so we have no worries about ground water and no moisture or humidity issues like some basements do.

 

[kenmac]

Great duct work is wrapped, not lined.

First came to NC and everyone tells me they don't use that duct board crap like they use up north, that they use sheet metal down here. What do they do? Line it. Wow:laughing:

LOL you should see the duct work the're installing in Arkansas. It would make you cry.
I visited my son that's doing an residency at a hospital there and he has been renting.

The hospital has offered him a job when his residency is up (this summer), so he took us around to look at new home's he's considering.

All new houses have Large metal box on the end of the AH. Then, large flex running supplying air to duct board boxes. Then the supply to the rooms come off these boxes. Then, more large flex to another duct board box and the same happens all over

I can't believe The state,or the city allows such crap ! I wouldn't install duct work in my dog's house like that.