New ICF Home Build.....I want to be....

[tlhfirelion]

really efficient, but also not break the bank. SO, this is a list of planned details so far;

All Nudura 6” ICF
All electric house
1500 sq ft on a crawl space, single story, basically a big rectangle in shape. 3 bed/2bath.
R50 (maybe 55-60) blown in cellulose in a raised heel truss attic. Attic will be air sealed with foam by me.
Woodstock soapstone absolute steel hybrid stove
Ecofan for wood stove
Ductless mini split heat pump (2 ton is what I expect)
Panasonic ERV pulling from bathrooms and dumping into hallway
Marathon water heater on a timer (off at night)
Windows will be double pane, unsure of what brand.
All appliances will be tier 3 rated/LED lights. Washer/dryer are front load with clothes line outside.
All LED bulbs.
16-24” soffit overhang.
Ceiling fans in each room to reduce AC use to some degree.
Layout of house is such that all the bathrooms and kitchen are close together. This allows saving on pex and not wasting water waiting for hot water. All lines will be insulated.

Now, I THINK I’ve covered all my bases while also keeping the budget in check. I’ll be doing a lot of the work myself, with some help from a friend that builds ICF. I’ve got my eye on solar but I’m unsure of what sized system I’d need since I have no energy usage history for this house. I certainly don’t want to oversize it as net metering in my area (Very NW AR) is a joke. If the budget allows towards the end of the build, I may start with a 4 KW system and an oversized inverter to be able to add as need be, all ground mount. I would like to someday have a sauna for their health benefits and want to factor that energy need in if possible.

So, my question to you, dear reader, is what else can I do to help reduce/prevent energy usage in this build. I want to focus on the conservation side before taking the plunge and purchasing a solar system.

Thank you in advance for your assistance.

 

[blades]

double think that all electric if NG is available ( usaully cheaper than electric for heating/ hot water, even ( good forbid) propane as a back up. Electric grid being what it is there are serious long duration outages, and a 4 kw solar system is not going to put a dent in those. Building new with a mortgage + Insurance co.- wood heat of any type is looked upon with disgust.

 

[tlhfirelion]

double think that all electric if NG is available ( usaully cheaper than electric for heating/ hot water, even ( good forbid) propane as a back up. Electric grid being what it is there are serious long duration outages, and a 4 kw solar system is not going to put a dent in those. Building new with a mortgage + Insurance co.- wood heat of any type is looked upon with disgust.

Thank you for your reply. NG is not an option where we are building, we’re out in the sticks. I’m not a fan of propane, never have been. Much prefer the simplicity of all electric after living in both types of homes over the years. We currently have wood heat and I’ve discussed our build with our current insurance guy. He knows I love wood heat and it will not be an issue.

 

[blades]

Thank you for your reply. NG is not an option where we are building, we’re out in the sticks. I’m not a fan of propane, never have been. Much prefer the simplicity of all electric after living in both types of homes over the years. We currently have wood heat and I’ve discussed our build with our current insurance guy. He knows I love wood heat and it will not be an issue.

Might not be with him but the under writer is where the rub comes in. ( got T shirt) my current home propane for conventional heater and hot water/ everythiing else electric, back up genny on propane also. NC30 wood stove main floor provides most of heat- ( course with neg 20deg F temps I need to run the propane furnace some to keep the basement a little warmer- don't want frozen pipes. poured basement - in and out of sill area insulated- still finding various leaks- like the 3" conduit that brings the electric in from under ground or the water spigots going out side. Have to address the fresh air supply side of the HRV system as well. Needs a damper that will close when unit not operating.

 

[3fordasho]

For heating water I would consider a Heat Pump Water Heater, still electric but power usage is way under 1K watts in heat pump mode, easy to switch to hybrid mode or straight electric element when usage exceeds what the heat pump can supply. I've never had to switch out of heat pump only mode with the two of us and a few quests once in a while, now if you have teenage daughters all bets are off. (previous owner of our house actually had two propane water heaters to keep up with his daughters bathroom habits)

Previous place had a NG dryer - very cheap to run. This place was only set up for a electric dryer and I didn't think I had time to run the gas line so I bought a new electric dryer - I regret that decision every time we run that electric dryer. Even on propane it's much cheaper to run a gas dryer.

 

[Woodsplitter67]

I would hold off on the solar for the first year. I my area your not allowed to oversize the system. You will be stuck installing an undersized system that my not put a dent in your usage. Im pretty sure any credits you get from the government is onetime. I woud see what my usage is and install somthing that will cover that amount of power

 

[tlhfirelion]

For heating water I would consider a Heat Pump Water Heater, still electric but power usage is way under 1K watts in heat pump mode, easy to switch to hybrid mode or straight electric element when usage exceeds what the heat pump can supply. I've never had to switch out of heat pump only mode with the two of us and a few quests once in a while, now if you have teenage daughters all bets are off. (previous owner of our house actually had two propane water heaters to keep up with his daughters bathroom habits)

Previous place had a NG dryer - very cheap to run. This place was only set up for a electric dryer and I didn't think I had time to run the gas line so I bought a new electric dryer - I regret that decision every time we run that electric dryer. Even on propane it's much cheaper to run a gas dryer.

I really like the heat pump water heater efficiency and I was looking at the heat pump water heaters. I started chatting with friends and relatives that have them. Out of 3, 2 had to replace them and the other had to replace the screen within the first 4 years. Ive had a marathon for 7 years with zero issues. Has yours been reliable? I’m a bit concerned about reliability there.

I will not be using gas or propane.

 

[tlhfirelion]

I would hold off on the solar for the first year. I my area your not allowed to oversize the system. You will be stuck installing an undersized system that my not put a dent in your usage. Im pretty sure any credits you get from the government is onetime. I woud see what my usage is and install somthing that will cover that amount of power

I think you’re right. My main reason for wanting to get it going now is to roll it into the mortgage payment, but it is a bit of a crap shoot to guess on size. Dang it. Lol.

 

[Woodsplitter67]

I think you’re right. My main reason for wanting to get it going now is to roll it into the mortgage payment, but it is a bit of a crap shoot to guess on size. Dang it. Lol.

Your at the Mersey of the utility. They have to ok the system size.. and sence you have no history they will definitely undersize you..

 

[3fordasho]

I really like the heat pump water heater efficiency and I was looking at the heat pump water heaters. I started chatting with friends and relatives that have them. Out of 3, 2 had to replace them and the other had to replace the screen within the first 4 years. Ive had a marathon for 7 years with zero issues. Has yours been reliable? I’m a bit concerned about reliability there.

I will not be using gas or propane.

I installed a whirlpool unit from Lowes in March 2015, not one issue so far. I do clean the air inlet filter on the top of the unit about every 6 months, a 2 minute job at most. It is in the same room as a wood furnace and that is the source of fly ash that collects in the filter. I did purchase a 8 or 9 year extended warranty through Lowes, it was priced the same as a regular water heater extended warranty (cheap)

 

[tlhfirelion]

Your at the Mersey of the utility. They have to ok the system size.. and sence you have no history they will definitely undersize you..

Not in my area. I spoke with them at length about it. They essentially told me it’s financially best for me to get as close to 100% coverage without going over, only because the net metering is not profitable like in other states. But if I want to do that, they just set it up different on their end. I’m out in the boonies and there are no real codes aside from well and septic and even those are basic.

 

[tlhfirelion]

I installed a whirlpool unit from Lowes in March 2015, not one issue so far. I do clean the air inlet filter on the top of the unit about every 6 months, a 2 minute job at most. It is in the same room as a wood furnace and that is the source of fly ash that collects in the filter. I did purchase a 8 or 9 year extended warranty through Lowes, it was priced the same as a regular water heater extended warranty (cheap)

Glad to hear you’ve had good luck. Does it make the room really cold as a side effect of the heat Pump?

 

[Seasoned Oak]

I really like the heat pump water heater efficiency and I was looking at the heat pump water heaters. I started chatting with friends and relatives that have them. Out of 3, 2 had to replace them and the other had to replace the screen within the first 4 years. Ive had a marathon for 7 years with zero issues. Has yours been reliable? I’m a bit concerned about reliability there.

I will not be using gas or propane.

I have a Geospring HPWH for almost 3 yrs zero issues.

 

[3fordasho]

Glad to hear you’ve had good luck. Does it make the room really cold as a side effect of the heat Pump?

It does drop the temp and humidity in the non-heating seasons, this time of year I've got plenty of excess heat from the wood furnace in the same room. The dehumidification in the spring/summer is a nice bonus too, have not needed to run a dehumidifier in the basement.

 

[tlhfirelion]

It does drop the temp and humidity in the non-heating seasons, this time of year I've got plenty of excess heat from the wood furnace in the same room. The dehumidification in the spring/summer is a nice bonus too, have not needed to run a dehumidifier in the basement.

I had completely forgot about the dehumidification. Interesting and that’s kind of important where I live. Well crap, now I’m considering it again. Lol.

 

[maple1]

I had completely forgot about the dehumidification. Interesting and that’s kind of important where I live. Well crap, now I’m considering it again. Lol.

Your mini-split will dehumidify. So will a HP water heater, if you get one. So will your HRV, but not in the summer.

So, my question to you, dear reader, is what else can I do to help reduce/prevent energy usage in this build. I want to focus on the conservation side before taking the plunge and purchasing a solar system.

I don't think you mentioned what should be the first consideration and easiest. Design & orient the house for good passive solar capture. Most glass on the south side. Build out eaves to the right length to block summer sun but let winter in. Trees on the side of prevailing winds. That kind of thing.

I would also go the mini-split & wood stove combo.

EDIT: Where are you located?

 

[tlhfirelion]

Your mini-split will dehumidify. So will a HP water heater, if you get one. So will your HRV, but not in the summer.

So, my question to you, dear reader, is what else can I do to help reduce/prevent energy usage in this build. I want to focus on the conservation side before taking the plunge and purchasing a solar system.

I don't think you mentioned what should be the first consideration and easiest. Design & orient the house for good passive solar capture. Most glass on the south side. Build out eaves to the right length to block summer sun but let winter in. Trees on the side of prevailing winds. That kind of thing.

I would also go the mini-split & wood stove combo.

EDIT: Where are you located?

The house will be slightly SE to NE, it’s really the only way to make it work n the lot. We’re in very NW Arkansas.

 

[tlhfirelion]

I’ve been extensively researching the HP WH and I’m still unsure. The complexity and expense if they go bad gives me pause. Also, when they’re not in heat pump mode, they seem to lose a lot of their adnpvamtage. If I had to decide now, I’d go with the marathon just due to longevity.

 

[tlhfirelion]

Do you folks think triple pane windows are worth the expense?

 

[blades]

Triple vs double the actual details is in the pane assembly itself - if the panes are separated by metal spacers there is going to be extreme conductivity at those points - some units made with plastic spacers- better, various coatings on the panes can change the thermal conductivity.. Gas or no gas between panes-- leakage has been an issue with argon injected ones in the past. dead air space - as long as it is dead dry is just as good. stll the seal can break down over time so warranty lengths are an issue.

 

[blades]

Forgot say that several years back when I was replacing windows on a different home the cost difference( 2 vs3) for R gain was not worth it at that time.

 

[semipro]

I know someone nearby that has a totally ICF house and one benefit he notes is how quiet it is - a benefit most don't consider.
I'd make sure and prepare for use of an outside air source for any combustion device, including your wood stove. Of course, your HRV or ERV will address that issue also.
We love our HPWH (GeoSpring) BTW but you do have to install it in the right place considering heat source, cold and dry air output, and some noise.
I really also like that we can run it off a smaller generator during power outages.

 

[begreen]

See if there is an Intus dealer in your area. These are efficient 3 pane and made in a number of styles.
https://www.intuswindows.com/
Also Ply Gem and Marvin make some good high-efficiency windows.

And if cost is no object, Zola makes an R=15 window
http://www.zolawindows.com/

 

[DBoon]

Your basic design sounds pretty well thought out. Good idea to do your own air-sealing - nobody will care about this as much as you do or do as good a job.

I'd say in NW Arkansas, triple-pane windows may not make sense as a cost-adder compared to a good double-pane window with Argon/Krypton fill - but it depends on a lot of things. Compare the R-value of the two options and calculate your heat loss/savings and you'll know what to do. Realistically, double-panes with tight window coverings are as good if not better.

If you have no net-metering for solar PV, I would consider a dual-axis tracker to maximize and levelize generation during the day. Then, I would put as many solar PV panels as I could on this one tracker (20 or 24 typically). That means you have a 5-6 kW system - believe me, if you have the power, you'll find a way to use it.

Then, I would find a way to use this PV electric generation when it was there. I would use the Marathon tank as a pre-heater tank for an air-source heat pump water heater. When it is sunny and you have excess generation, make that heat water to 140 degrees F and store some of that excess electricity as heat. Not super efficient, but if the utility is not paying you for this electricity anyways, might as well use it instead.

For your house heating needs, you might want to consider a geothermal heating system with a big storage tank. I have a 180 gallon tank (Stiebel Eltron) that my ground-source heat-pump (GSHP) heats and then I use radiant floor heat for the house (this is a renovation I am completing). In my cold climate, the 180 gallon tank can store 5 hours of heat. In your climate, it might store enough to heat your house overnight. This system was not cheap, but it is very efficient and it works. Plan on having to design/install the radiant floor yourself. Bonus - if you are building a new house, your radiant floor can be optimized during the design instead of having to do a retrofit with tubes and metal plates (more expensive, and more difficult to install). This would be a good system for the wood-stove backup, or when you were away and/or didn't want to run the stove.

Good luck. Let us know how you proceed.

 

[begreen]

I'd say in NW Arkansas, triple-pane windows may not make sense as a cost-adder compared to a good double-pane window with Argon/Krypton fill - but it depends on a lot of things. Compare the R-value of the two options and calculate your heat loss/savings and you'll know what to do. Realistically, double-panes with tight window coverings are as good if not better.

Agreed, I just read the end of the thread and missed the location. Not necessary unless the goal is to have a zero-energy home.