Designing heating and cooling for a new build.
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timselectric
If I can do it, you can do it.
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timselectric
If I can do it, you can do it.
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New house would have radiant floor, first.
With geothermal as a source. And mini splits for the less used areas. And yes, a sand battery for sure.
It's the only affordable way I can find to heat in winter with summer production.
With geothermal as a source. And mini splits for the less used areas. And yes, a sand battery for sure.
It's the only affordable way I can find to heat in winter with summer production.
If you have geothermal as a source. What is the need for mini splits?
timselectric
If I can do it, you can do it.
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Mostly a backup.
I love redundancy.
DIYrich
Solar Wizard
Hybrid system. The geothermal is the central unit with mini heat exchangers in the individual rooms.
Tim's not wrong. A geothermal system could heat or cool water for the radiant floor. I'd differ with the minisplits and put a high velocity air handler in for supplemental heating and air conditioning.
My new build has a similar system, but instead of a geo pump we use monoblock air to water heat pumps.
My new build has a similar system, but instead of a geo pump we use monoblock air to water heat pumps.
I also vote ground source heat pump with radiant flooring for heating. Backed up by mini splits and wood heat.
For A/C, mini splits with backup window units sitting safely in storage. I would also consider a room or two thats buried deep and maybe even some earth tubes with natural air flow. Not sure how to keep them from getting musty. That way you can still have some where cool to sleep during the apocalypse
For A/C, mini splits with backup window units sitting safely in storage. I would also consider a room or two thats buried deep and maybe even some earth tubes with natural air flow. Not sure how to keep them from getting musty. That way you can still have some where cool to sleep during the apocalypse
EastTexCowboy
Solar Wizard
Mini splits with ducted air handlers is another option, but maybe not as efficient as separate units, depending on how you used them. Coupled with geothermal would be ideal. As I understand geothermal, it will get you part or even most of the way there but on the really hot or cold days it needs some assistance.
mrdavvv
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One idea that i have seen, wich might be the one you are referring too.. its buring some PVC tubes and put an helicocentrifugal extractor to move the air when needed. Cool air for cheap... but not sure if it will work.
For AC definitely minisplits, so you can have redundancy and get something like SEER+20 units. Maybe think about evaporative cooling if your humidity allows for it.
Without a doubt, in that climate, I'd go with an air source mini split heat pump. AC + heat, very efficient with generally ~ 3:1 coefficient of performance, and in your area, will likely never be cold enough for them to perform poorly.
We have two Daikins (not bad) and one Mitsubishi (fantastic) in three separate buildings, and I live in Maine. Even at sub-zero, they kept us nice and toasty. We'll put a Mitsubishi in the next house we build, as well. There are lots of different, somewhat exotic ideas people have about how to heat and cool a house. But for a reliable, relatively carefree approach to using solar, it's just about impossible to beat a modern heat pump mini split from one of the top tier brands.
We have two Daikins (not bad) and one Mitsubishi (fantastic) in three separate buildings, and I live in Maine. Even at sub-zero, they kept us nice and toasty. We'll put a Mitsubishi in the next house we build, as well. There are lots of different, somewhat exotic ideas people have about how to heat and cool a house. But for a reliable, relatively carefree approach to using solar, it's just about impossible to beat a modern heat pump mini split from one of the top tier brands.
Your probably right with some of the newer flooded condenser switching they are doing. The ground source is such a hugh up front cost.
I would love to see the power use numbers of a water source(55F) vs -10F to say 30F air source over a season. I'm sure the buy back difference would still be 10+ years BUT.....if someone had the ability (which many do) to put in their own ground source, it would be worth it.
OzSolar
Whatever you did, that's what you planned.
I'm in southern Missouri. At my house we have passive solar high mass, radiant infloor, geothermal, a wood boiler and miniplits but I wouldn't steer you that way precisely.
In order: Passive solar high mass design, mini-splits, propane and biomass (firewood).
Forget geothermal unless you've got money to waste. Very few contractors around here do it (well) and in 10 years there won't be any so good luck getting it worked on.
All of my off grid customers from the last 10 years or so have mini-splits, radiant in floor, propane and at least one 120g electric water heater (some have up to 5) with a 5,500 watt element.
Crazy, right? Well not if you think about it. Once you've got enough PV and inverter to run a few minisplits in the summer you've got a ton of spare capacity in the shoulder months and more than a few days in the dead of winter. Dump all that capacity into heating water for use in a radiant infloor heating later on. When there's not enough free hot water the propane boiler fills in the gaps.
In order: Passive solar high mass design, mini-splits, propane and biomass (firewood).
Forget geothermal unless you've got money to waste. Very few contractors around here do it (well) and in 10 years there won't be any so good luck getting it worked on.
All of my off grid customers from the last 10 years or so have mini-splits, radiant in floor, propane and at least one 120g electric water heater (some have up to 5) with a 5,500 watt element.
Crazy, right? Well not if you think about it. Once you've got enough PV and inverter to run a few minisplits in the summer you've got a ton of spare capacity in the shoulder months and more than a few days in the dead of winter. Dump all that capacity into heating water for use in a radiant infloor heating later on. When there's not enough free hot water the propane boiler fills in the gaps.
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Cooling with radiant floors requires dehumidification via another system, that is where mini splits or an outside air system come into play. I was in a house a while back that just circulated ground loop water in the radiant slab year-round, but when ground water temperature was within 5F of dew point it would have to shut off.
If you have enough land that is easily trenched then ground source is great. Or if you are drilling a water well anyway and can have the contractor do a few extra boreholes cheap it makes sense. I would stick with water based systems though and provide inherent freeze protection-- bury below the frost line and put an inch of insulation above the pipes.
First priority is a tight house with good insulation and vapor barrier, and an energy recovery unit to manage exhaust and make-up air. After that thermal mass comes into play.
If you have enough land that is easily trenched then ground source is great. Or if you are drilling a water well anyway and can have the contractor do a few extra boreholes cheap it makes sense. I would stick with water based systems though and provide inherent freeze protection-- bury below the frost line and put an inch of insulation above the pipes.
First priority is a tight house with good insulation and vapor barrier, and an energy recovery unit to manage exhaust and make-up air. After that thermal mass comes into play.
Though I am not in US but weather in Pakistan is very similar to yours.
Like OZSolar said:
I have a 10.8KW grid tied PV Panels and as of writing of this email it has produced 21k kwh (including regular power breakdowns during this period). The chart has actual data with Jun 2023 figures extrapolated but they are very accurate based on my last year's generation and usage.
For cooling we use mini splits 18000 btu (3) in summers. Our net metering is 1:1 except from (6-10p.m higher rates). After 16 months of solar I haven't paid anything to utility.
In winters (Dec-Feb)I have an old gas boiler with 10 rads + domestic hot water, it consumes a lot of gas; 19000kwh. This winter I am going to take off DHW from gas to solar via immersion heaters. I have a 1500w x 2 immersion heaters installed in a cylinder for water heating. During the day will put mini splits on for heating and in evening will use gas boiler from 4-10 p.m as gas prices are going up. My aim is to bring down gas usage from 19k to 15kwh. Fingers crossed for the winters.
Axis titles jumbled up; primary axis has kw/month and secondary axis $/kwh
Like OZSolar said:
I have a 10.8KW grid tied PV Panels and as of writing of this email it has produced 21k kwh (including regular power breakdowns during this period). The chart has actual data with Jun 2023 figures extrapolated but they are very accurate based on my last year's generation and usage.
For cooling we use mini splits 18000 btu (3) in summers. Our net metering is 1:1 except from (6-10p.m higher rates). After 16 months of solar I haven't paid anything to utility.
In winters (Dec-Feb)I have an old gas boiler with 10 rads + domestic hot water, it consumes a lot of gas; 19000kwh. This winter I am going to take off DHW from gas to solar via immersion heaters. I have a 1500w x 2 immersion heaters installed in a cylinder for water heating. During the day will put mini splits on for heating and in evening will use gas boiler from 4-10 p.m as gas prices are going up. My aim is to bring down gas usage from 19k to 15kwh. Fingers crossed for the winters.
Axis titles jumbled up; primary axis has kw/month and secondary axis $/kwh
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justinm001
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My home has Radiant floor heating in basement and it's pretty pointless. Just feels nice keeping toes warm but doesn't seem to heat efficiently, although we don't use our basement.
I have a geothermal water furnace brand and it's great. Best part is it's extremely quiet and no box outside. Mine uses dampers for multi zone which is ideal. House came with it built-in 08. I've had house for 5+ years and only issue was when we bought the house the capacitor needed replaced from sitting for a year.
My other houses all have multiple AC units, either traditional AC, heatpump or minisplits and there's constant issues with massive energy bills.
I have a geothermal water furnace brand and it's great. Best part is it's extremely quiet and no box outside. Mine uses dampers for multi zone which is ideal. House came with it built-in 08. I've had house for 5+ years and only issue was when we bought the house the capacitor needed replaced from sitting for a year.
My other houses all have multiple AC units, either traditional AC, heatpump or minisplits and there's constant issues with massive energy bills.
Quattrohead
Solar Wizard
With the newer inverter compressors and better technology in general for both split and mini split systems I think the KISS method is better than ever. Surely air source heat pumps are the cheapest and hence the most efficient install available now.
Hey Oz, Im probably not to far from you. Yea, not allot of deep soil in the Ozarks for putting in ground loops.
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