New Home HVAC System

[Frankenkubota]

Yours sounds just like ours. We did closed cell walls and underside of roof. Timberframe home so very little attic space. Just a very small area above the 3 bedrooms on the upper level.



Sigarms house was built 6 years ago so your assumption was correct. I agree on the absurdity of how money is spent on new homes. We hit our coldest temp so far in this home the other night at minus 21. Coldest I can ever recall in this area. Units ran most of the night but rarely saw all zones calling at once and kept temp just fine. On the flip side a friend of ours had a new build high end home with frozen water lines on one wall and a bedroom over a garage that was so cold it was unusable. Would love to see the insulation job behind the sheetrock.

-21? Was that temp or wind chill? Man oh man, i'm gonna quit whining......at least for a few minutes.

 

[Sigarms]

Sigarms house was built 6 years ago so your assumption was correct. I agree on the absurdity of how money is spent on new homes. We hit our coldest temp so far in this home the other night at minus 21. Coldest I can ever recall in this area. Units ran most of the night but rarely saw all zones calling at once and kept temp just fine. On the flip side a friend of ours had a new build high end home with frozen water lines on one wall and a bedroom over a garage that was so cold it was unusable. Would love to see the insulation job behind the sheetrock.

No word of a lie... A front door on a high end home I came across cost more than the HVAC system to install.

People have no qualms throwing money at fixtures, but God forbid when it comes to your HVAC and duct system (along with insulation) that will cost you more or less money every month per your utility bill for as long as you live in the house, depending on what you spend and do.

Never been to Missouri other than St. Louis for work (and hearing in my youth that Ft. Leonard Wood sucks LOL) but never thought it got that cold in Missouri.

Out of curiosity, what does your average utility bill run you during the summer and winter? For myself, 1 heat pump, 1 dual fuel system and one gas/AC system, I'd average about $325 during summer and winter. Thing is, that doesn't include the LP my dad uses down in the basement for heat (his temp set to 75 year round, other two floors average about 70 in winter and 74 in summer). Not the greatest, but for what I have and when the house was built, better than average IMO and from what I've seen for the size of house.

 

[jk96]

-21? Was that temp or wind chill? Man oh man, i'm gonna quit whining......at least for a few minutes.

Actual temp before wind chill.

 

[jk96]

Out of curiosity, what does your average utility bill run you during the summer and winter? For myself, 1 heat pump, 1 dual fuel system and one gas/AC system, I'd average about $325 during summer and winter. Thing is, that doesn't include the LP my dad uses down in the basement for heat (his temp set to 75 year round, other two floors average about 70 in winter and 74 in summer). Not the greatest, but for what I have and when the house was built, better than average IMO and from what I've seen for the size of house.

We are all electric. Around $300-$320/month coldest months of Dec/Jan and around $230/month in the hottest months of June/July. Last two winters I've been lazy and haven't burned any wood. If we utilize the fireplace I can cut my winter usage significantly. Once the 3 kids are out should see another drop. Our washer/dryer seems to run non-stop.

Edit: We are in Northwest Missouri

 

[Sigarms]

We are all electric. Around $300-$320/month coldest months of Dec/Jan and around $230/month in the hottest months of June/July. Last two winters I've been lazy and haven't burned any wood. If we utilize the fireplace I can cut my winter usage significantly. Once the 3 kids are out should see another drop. Our washer/dryer seems to run non-stop.

Edit: We are in Northwest Missouri

Curious if you have strip heat for back up heat on those geo units? Being more curious, what's your electric rate? We're at about .11 per KW.

$320 for heating your size house in the Winter is way above average IMO without using any other supplemental heat other than electric.

Utility company has "peak hours" here. My wife is like ****** when anyone can do laundry except for my dad, but we end up doing it for him and as long as it gets done that day, he's happy.

That's the thing about mini splits. It may be a 30 SEER system, but to get max heat, that compressor is running full load to maximize the heating capacity, and that costs more money than AHRI "rated" performance (compressor rated at around 50-60% load).

 

[jk96]

Curious if you have strip heat for back up heat on those geo units? Being more curious, what's your electric rate? We're at about .11 per KW.

$320 for heating your size house in the Winter is way above average IMO without using any other supplemental heat other than electric.

Utility company has "peak hours" here. My wife is like ****** when anyone can do laundry except for my dad, but we end up doing it for him and as long as it gets done that day, he's happy.

That's the thing about mini splits. It may be a 30 SEER system, but to get max heat, that compressor is running full load to maximize the heating capacity, and that costs more money than AHRI "rated" performance (compressor rated at around 50-60% load).

Our electric rate is .12 per KW. That cost posted is whole house electric bill, not just heat. Not sure exactly how much is for heat only. Breakers for heat strips are off so that they do not kick on.

 

[truckdiagnostics]

Thing is, what's easier to run, electrical or gas lines?

Run water lines and heat and chill the water? i believe that is how they are doing it the office buildings. The air handler makes 50 degree air. Then they heat the air going into the individual zones using water air exchangers and they are using water source heat pumps to move the heat around?
Kid is into the commercial heavy stuff craning compressor on roofs and what not. I only dabbled in my own stuff and residential forced air, and I was only changing parts. I was young at the time and didn't know a lot. Got the kid in the business then helped him out, stuff is not rocket since. He is in it big time now, and i know enough to dangerous.

 

[Sigarms]

Our electric rate is .12 per KW. That cost posted is whole house electric bill, not just heat. Not sure exactly how much is for heat only. Breakers for heat strips are off so that they do not kick on.

At -18F without strip heater, you're doing great maintaining heat without a fossile fuel.

 

[Sigarms]

Run water lines and heat and chill the water? i believe that is how they are doing it the office buildings. The air handler makes 50 degree air. Then they heat the air going into the individual zones using water air exchangers and they are using water source heat pumps to move the heat around?
Kid is into the commercial heavy stuff craning compressor on roofs and what not. I only dabbled in my own stuff and residential forced air, and I was only changing parts. I was young at the time and didn't know a lot. Got the kid in the business then helped him out, stuff is not rocket since. He is in it big time now, and i know enough to dangerous.

To ensure we're on the same page, what are you proposing for residential use for home heating and cooling, not commercial use?

To some extent, why Geothermal is one of the best sources for HVAC for residential use, but also more expensive than forced air.

 

[jk96]

At -18F without strip heater, you're doing great maintaining heat without a fossile fuel.

The night we hit -21 I checked my usage on the units. From midnight to 8 am each unit ran just over 7-1/2 hours so they ran almost non-stop but maintained a 73 degree setpoint in all zones. Incoming water temp from my loop as of yesterday was 38 degrees so loop is holding up well this winter. Units are putting out a 21-22 degree delta T on the heat side.

 

[Sigarms]

The night we hit -21 I checked my usage on the units. From midnight to 8 am each unit ran just over 7 hours so they ran almost non-stop but maintained a 73 degree setpoint in all zones.

Just curious why 73 on all zones unless that's what you've got to work with per the duct layout? I would just think that the unoccupied space when zoned would be set higher or lower on the t-stat depending out outside air conditions.

Because the dogs are on our first floor, keep it at 64 between at night and early morning during winter. Third floor is generally 68 at night (in winter) while the basement is no lower than 74. I did install a whole house dehumidifier for the home that allows me to run a higher than normal t-stat setting in the summer (generally around 77F on the first floor), but that draws a good amount of power as well and offsets the higher t-stat setting in the summer, but the wife loves the comfort.

Note - one advantage of a multi zone mini split when in heating or cooling mode. You can maintain individual zone temps for each room. You can't however have one zone call for heat and another call for cooling. That's the advantage of commercial VRF ductless systems.

 

[jk96]

Just curious why 73 on all zones unless that's what you've got to work with per the duct layout? I would just think that the unoccupied space when zoned would be set higher or lower on the t-stat depending out outside air conditions.

Because the dogs are on our first floor, keep it at 64 between at night and early morning during winter. Third floor is generally 68 at night (in winter) while the basement is no lower than 74. I did install a whole house dehumidifier for the home that allows me to run a higher than normal t-stat setting in the summer (generally around 77F on the first floor), but that draws a good amount of power as well and offsets the higher t-stat setting in the summer, but the wife loves the comfort.

Note - one advantage of a multi zone mini split when in heating or cooling mode. You can maintain individual zone temps for each room. You can't however have one zone call for heat and another call for cooling. That's the advantage of commercial VRF ductless systems.

I used 73 as I was too lazy to type it all out and this is our main living space. Zones: Living room - 73, Dining/kitchen/laundry - 71, Master - 70, Upstairs left - 71, Upstairs right - 71, Basement - 69 Basement rarely calls for heat at that temp and maintains close to that in the summer without cooling so there's around 900 sq/ft that doesn't require much. Main living room is vaulted across the entire center of home so the upstairs zones get less calls in winter as well.

 

[lman]

To ensure we're on the same page, what are you proposing for residential use for home heating and cooling, not commercial use?

To some extent, why Geothermal is one of the best sources for HVAC for residential use, but also more expensive than forced air.

My geothermal is forced air. My strip heaters have never run as they have been disabled. It was -20 a couple years ago, -10 a couple days ago. Confused what you're trying to say.
My geothermal can't be more expensive than forced air because it is forced air.

 

[jk96]

My geothermal is forced air. My strip heaters have never run as they have been disabled. It was -20 a couple years ago, -10 a couple days ago. Confused what you're trying to say.
My geothermal can't be more expensive than forced air because it is forced air.

I think he's referring to a standard forced air setup vs geothermal water to air.

 

[Sigarms]

My geothermal is forced air. My strip heaters have never run as they have been disabled. It was -20 a couple years ago, -10 a couple days ago. Confused what you're trying to say.
My geothermal can't be more expensive than forced air because it is forced air.

I should of stated "air to air", apoliges for the incorrect terminology. When I say "forced air", I meant air to air source but did not specify that.

Yes, geo units have a blower to move the air just like a standard heat pump air handler, thus it's "forcing" the air to move.

That's why when someone says "VRF" vs "ductless mini split", there is a difference IMO. I actually do more inverter mini splits and VRF for commercial than Geothermal in my area. Federal tax credits going away in NC kind of killed the geo market in my area, and the local utility companies don't offer much bigger rebates with water source vs air to air systems.

 

[Sigarms]

I used 73 as I was too lazy to type it all out and this is our main living space. Zones: Living room - 73, Dining/kitchen/laundry - 71, Master - 70, Upstairs left - 71, Upstairs right - 71, Basement - 69 Basement rarely calls for heat at that temp and maintains close to that in the summer without cooling so there's around 900 sq/ft that doesn't require much. Main living room is vaulted across the entire center of home so the upstairs zones get less calls in winter as well.

When you parents move into your basment, the heating will be set higher than anywhere else in the house. Just a heads up LOL

 

[jk96]

When you parents move into your basment, the heating will be set higher than anywhere else in the house. Just a heads up LOL

I have no doubt. Dad's house about cooks us when visiting and still uses an electric blanket.

 

[RalphVa]

We are in the planning stages of building a new house. My original thought was to have a standard central air and heat ducted system using heat pump with propane backup. We also will have non vented fireplace with gas logs for supplemental or backup heat if the power goes out.

In talking to a friend who retired from the HVAC world he suggested looking at a Mitsubishi Multi Zone Mini Split System. Multi-Zone Cooling and Heating Outdoor Units | Mitsubishi Electric

Are any of you guys using a system like this in your house or have any knowledge of it? I have studied it some and it certainly looks interesting. I like the idea of each room/area temperature being controlled independently. I also like the idea of no duct work as well.

I'd go with the ductless ones. Ours is Fujitsu. They're more efficient than the ducted units. However, our newest (2 ton) ducted unit for the upstairs runs without having the backup electric coil. We've it shut down via thermostat. Cannot have the coil available if on backup generator. Ductless do not use any coil backup.

Ralph

 

[RalphVa]

Goethermal would be even more efficient than dustless. If you have space to lay the underground lines for it or can put in a separate well for it, it's the way to go. We don't have the space for it here.

Ralph

 

[Sigarms]

I have no doubt. Dad's house about cooks us when visiting and still uses an electric blanket.

LOL My dad uses an elctric blanket as well when he's sitting on the couch watching TV and it's it's still 75-77F down there.

To put an oil boiler into perspective for heating, at his old house, he never put the T87 tstat past 72. Can't beat radiant heat for the warm feeling.