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If you were designing a heating system for dream house/dream shop, what would it be and what design

rocket190rocket190 Member Posts: 14
I'm currently designing a shop building (2400 first floor, 2400 basement), so a shop building is of more interest to me, but a large house would be the same.

Since it's not built yet, I have a clean slate and am leaning toward radiant in floor.

Let me know what your dream system is, and what design tweaks would you require prior to construction to make sure your system is comfortable and efficient.

Assumptions: Norther climate (8,000 hdd or more), excellent insulation R60 ceilings/R40 walls, and tight air sealing.


  • heatpro02920heatpro02920 Member Posts: 991

    Just heat, no AC or DHW? If so...

    I would do 2 Water Furnace series 5's with 2 Smart 80 storage tanks and run radiant through the floors, with all the bells and whistles, prestige thermostats, floors sensors, delta t circs, ect...

    If you wanted a/c and dhw I would do Forced air over radiant and do Water Furnace series 7's with the correct sized smart tank for dhw...

    Then if money was really no object I would add a serious solar system to that to power the geothermal systems.... Bu that would require one heck of an investment..

    Besides the price of the equipment, you would need to buy all the tubing and have all the wells drilled, but I have done $80K geo systems that will pay for themselves in 12 years vs a conventional oil fired system, but for it to make sense you need to have the load of a huge space...
  • Jamie HallJamie Hall Member Posts: 6,693
    edited March 2013
    What might be called

    semi-active solar.  100%.  I've participated in the design and construction of about half a dozen houses, one aircraft hangar, and one school dining hall which get all their heat (domestic hot water and space) from solar -- in a central New England climate.

    So I know it can be done, and if I were to do it for a dream house, that's what I would do.

    There is a cost premium -- about 10%, in my experience, on the overall building cost.  But the end result sure is nice...

    (So why am I caring for the place I'm in?  Perhaps better not to ask...!)

    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.

    Hoffman Equipped System (all original except boiler), Weil-McClain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
  • Paul PolletsPaul Pollets Member Posts: 3,022
    Where are you?

    Does the property have natural gas or propane? Is electric less than $.10/KWH?

    Sounds like you may be in Alaska with 8000dd!

    I'd do a radiant floor system with a modulating boiler and indirect DHWT. Most comfortable and very efficient with a highly insulated space. I'd use an HRV for the ventilation. The low water temps required for the RFH could easily be calculated, depending upon the application.
  • rocket190rocket190 Member Posts: 14
    Not Alaska, but the Frozen Tundra

    Well I live close to Green Bay, WI, so does indeed get cold here, but I don't think Alaska cold!

    My available fuel is propane or electric. For the time being, propane is $1.39 gallon...although in the last 5 years t his has fluctuated between $2.19 and .99. Electric is expensive here. $0.14/kw.

    I work for a family excavation company, so anything underground can be done cheaply by us. However, I've never spoken with anyone that has saved a ton of money with geothermal after they figure increased electric costs. I wish I worked for a family foam company. Sure would be nice to have a semi load of extruded foam!
  • rocket190rocket190 Member Posts: 14
    Heat only

    Forgot to mention, for me this is a heat only system. It's a shop--bearable in Wisconsin summers. Besides the humidty, it's usually not that hot. DHW needs are so low that a point of use tankless makes the most sense.
  • hot rodhot rod Member Posts: 7,059

    install the tube at a tight spacing, maybe 6" so it can use the lowest possible supply temperatures.

    If you have excavating equipment, and enough land, a heat pump with a pit type loop field could be the most efficient way to heat, while offering cooling and some DHW potential.

    Check all them rebate programs available in your area,including your power provider. My small electric co-op has a $750.00 per ton rebate in addition to any state or federal programs.

    Define the building, do a load calc with them insulation values you are considering and do some cost comparing. If you can do them loop field installation that is a big part of the GEO cost.

    Passive and some active solar would be at them top of my list also.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    The magic is in hydronics, and hydronics is in me
  • moeymoey Member Posts: 40

    geothermal enough said, don't be scared it works don't use oil or propane. If you have a lot of property a horizontal loop not much property a vertical loop. 30% discount right now. 
  • rocket190rocket190 Member Posts: 14
    Geo in sand?

    Well, we have the excavating equipment and I have 66 acres of land to work in. Generally the soil in my area is heavy red clay, but where I'm building it's a gravelly sand. Is it possibly to overdig the building (I will have a basement) and lay the loops around the building perimeter? I can't say that I've seen a loop field installed this way, but it seems like a money saving idea--even for us.
  • heatpro02920heatpro02920 Member Posts: 991
    Put the loops

    where ever you want just make sure they are deep enough and enough tubing is used. Like in my first post geo is the way to go, and since you don't need ac, the WF series 5 units are really nice..
  • Charlie from wmassCharlie from wmass Member Posts: 3,922
    you would chill your building as

    you tried to heat it. Kind of like being on a tread mill. Keep the loops away from the building
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
  • hot rodhot rod Member Posts: 7,059
    plenty of GEO

    installed in Wisconsin large and small. Fond du Lac high schools conditions about 425,000 square feet with pond loop GEO. Here is a link to some info close to your area.

    I'd hire a GEO contractor with experience to at least do a load calc and design for you. It's important that then loop field design is right.

    There is a good GEO association in Wisconsin also. They have actual operating data on many of the systems, no need to guess about operating costs and work ability for your area.

    The key is you get 3-4 times the energy out as you put in, 1 unit of electricity 3-4 from the ground. So a heat pump with a COP of 3.6 for example = 3.6 units of output per unit of electrical energy input.

    A radiant slab running 100F or lower supply would be a good match for geo. The closer the load temperature to the source (ground) temperature the higher the efficiency.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    The magic is in hydronics, and hydronics is in me
  • rocket190rocket190 Member Posts: 14
    New things to ponder

    I'm glad I asked this question, as I am now considering system types that I would have never thought of before.

    If I would use geo, it would definitely be a loop system in ground. I have a 4 acre pond, but it's a 1000' away and I don't want to dig up my hole yard. Anyways, a loops system is easy for us to excavate.

    Would you recommend a fluid to air heat exchanger that get's used in conjunction with forced air furnace? Can this also be used for cooling? Or would you do in floor in conjunction with some type of boiler?

    The more I think about my situation, the more I'm leaning toward a heating system that can quickly be raised or lowered to save energy when it's not being used. I'd like to think I'll be working in the shop more often, but realistically a few nights a week and probably every other weekend is what I'll have time for.

    Of course--if the building is cheap enough to heat that I can "set it and forget it" I'm not opposed to that either. I just can't justify spending $3,000 year on heat for my shop. My home is heated on approx 500 gallons of propane/year.

    I still think I will install the tubing so it's there if I'm able to retire early.....ha!
  • hot rodhot rod Member Posts: 7,059
    water to water

    moves the energy from the loop field into the heat pump and warms or cools a fluid. Then you cann heat with radiant or mair coils, and send chilled water innthesummer months for cooling. DHW comes from a HX onboard the heat pump, so 3 functions in one.

    With water to water you pipe the warm/ chilled fluid to the fan coils as you mentioned. You can blend the radiant with the air handlers, but design those coils to run at the lowest possible supply temperature to keep the COP high.

    Here is a link to a good read on GEO and mixing it with modern hydronics.

    I put a water to air in the mother in laws last summer, an upgraded system from the 15 year old one. Pond loops for a 3 ton system. I used Bard equipment and set the heat pump on an indirect tank for a buffer tank. The coil in the tank connects to solar panels on the roof for additional heat input from the sun. The solar provides plenty of DHW during shoulder seasons before the HP needs to fire up.

    Here is the system being installed, the solar is a drain back system the small expansion tank is the DB tank.

    Designing the radiant to run at low temperatures also allows you to use solar thermal panels at a high efficiency. Design for 100- 120F supply if possible on the radiant, good for the HP and a solar component and also ideal for mod con operating efficiency as a backup sourse.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    The magic is in hydronics, and hydronics is in me
  • heatpro02920heatpro02920 Member Posts: 991
    edited March 2013
    I ussually

    go water to water for hydronic systems and water to air for a/c systems... I have done water to water for cooling but you need an extra piece of equipment.... Much easier to go water to air if you are doing duct work. And if thats the case the WF series 7s are amazing
  • rocket190rocket190 Member Posts: 14

    Heatpro and Hotrod--Thanks for the help. Do you specialize in mostly geo work, or do you install all system types? I will check out the link for further reading tonight--I'll gladly read anything. I like to learn. Have either of you seen the book "Modern Hydronic Heating"? It comes with great reviews, but it's pricey....around $200.
  • heatpro02920heatpro02920 Member Posts: 991
    Specializing in Geo only is tough

    I do as much as I can but the truth is, I couldn't live off geo alone, I install all kinds of heat, and do my best in each...

    I have a copy of MHH in my office {I paid like $50 for it though lol}... I think I spend a few hundred a year on books, IEBC and IBS books are $100+ each... and they dont last forever, since they are always changing codes..

    Geothermal is definitely the way to go, it adds value to your property more than any other systems, lasts just as long if not longer than other types, very efficient, but the initial cost can be 5-10 times higher than other systems... I have a program that shows what you will save over 30 years if you roll it into your mortgage, even after paying intrest over 30 years you will make money every time...
  • SWEISWEI Member Posts: 7,356
    you will make money every time...

    in the right climate, with a properly sized and installed system.

    But you know that...
  • RobGRobG Member Posts: 1,850

    What kind of tubing are you all using for geo HDPE or barrier pex? If you are using pex as a pond loop, have you encountered any UV problems?


  • rocket190rocket190 Member Posts: 14
    Air infiltration for shop

    Thanks for the link to the geo site. That is an excellent explanation of systems.

    I've been playing around with various heat loss calculations--What is a good figure to use for the air tightness of an outbuilding? I was only planning on one overhead door to help minimize air leakiness. The rest of the building will have 2" foam from footing to eaves (taped and caulked joints). I'm also very detailed about flashing windows, caulking potential air leak areas, etc.

    Has anyone ever blower door tested a garage to see how they are? I'm in the process of researching the most air tight and energy efficient garage doors...Not much exists in this department.
  • LarryCLarryC Member Posts: 331
    What is the intended shop use?

    What is the intended shop use?

    Making the building airtight could lead to some issues with respect to indoor air quality if you intend to do wood working.  Same with volatile solvents like gasoline, paint thinners, PVC cements, etc.  Smoke from welding and machining could also build up to unhealthy concentrations.

    Just something to think about, in addition to the energy conservation concerns.
  • rocket190rocket190 Member Posts: 14
    Air quality issue from woodworking?

    The shop will be primarily for woodworking. Also some light mechanical work and general storage. I typically use central dust collection and also ceiling hung small micron filtration units. Besides dust, i can't see how a tightly constrcted building would lead to air quality issues...or rather how would a leaky building help? In any event, i think the oh doors will limit the building from being exceptionally airtight even ifto get finishe everything else was done perfectly.

    Paints and solvents i agree with...nasty things. I usually bring my projects somewhere else
  • LarryCLarryC Member Posts: 331
    Woodworking dust

    I don't know his name, but a woodworker was on a mission to get woodworkers to exhaust their dust collection systems outside.  He developed a serious lung condition after using top rated recirculating dust collectors.  The issue was the 1 - 20 micron range sized particles that just pass thru the filters and stayed airborne.

  • heatpro02920heatpro02920 Member Posts: 991
    Down draft

    This could get tricky with in slab radiant, but a nice down draft system would be ideal.

    I designed one in a small building, I used a down draft grate along 2 of the outside walls {similar to a floor drain 9"s wide X 12 feet long strong enough to drive a car on}, then used a pair of fan units and a pair of HRV units for makeup air {which also recovered the heat energy of the outgoing air} ... It was a home garage 3 car that he used for building custom cabinets and between the fumes and dust his wife didnt want him doing it in the new house so when he was building he had me do the system to see if it would help, I made no promises but it has worked out better than even I expected... I originally installed air filter on the outside so he didnt blow dust in his driveway, but they were clogging too fast, so we installed some strategically bent sheet metal and a 50 gallon drum, kind of like a trap and drop system, worked good, but I can't take credit for the dust trap system that was all my empolyees doing, he seen it before when he worked on restaurant grease traps years ago...
  • RodmanRodman Member Posts: 9
    forget the "tweaks"

    First, I would like to tell you that you want to use a good quality 80% hot water boiler.  Do not fall for these modcons.  I live in the Chicago area (in 80 year old home), and have a 40 year old boiler with very large radiators; 6-7' long along with some copper tube baseboard.  My roof is insulated and 60% of the home is uninsulated.  I just totalled my gas bill for the last 12 months and it was $1,083.41, and if you take out the monthly usage for gas dryer and water heater, my heat bill was $783.41.  It doesn't get any better than that.

    Why do I say 80%-84%?  Modcons need annual service that cost $300.  Their lifetime is about half of a cast iron.  They are twice the cost to install, generally.  They will break down a lot more than a cast iron, and many of their parts are quite expensive.  They also "lockout" which requires a repairman.  With a 80% cast iron, there are only 5-6 parts that can go bad, and they hardly ever do that.  I have been in my house for 14 years now, and not one thing has needed a repair.  With a cast iron, you can "maintain" it yourself.  What I mean by this, is that every year or every other year you turn it off and vacuum out the entire burner area, check the flame height (and adjust if necessary; instructions can be found on the internet), check the flue periodically for condensation; as there should be none.  Rust is a sign of condensation.

    Buy the largest USED radiators that you can find and connect them with black pipe.  Many on this website are in love with their modcons, but even Burnham is coming around, and saying there is nothing like cast iron for overall efficiency.  The 84% efficiency boiler I mention at the beginning has a couple of extra parts (exhaust fan and lockout control in case the flue damper does not open).  This boiler is a direct vent and sealed combustion.  It draws its combustion air from outside the building.  The difference in it and my 80% is that my 80% uses the air in the building, which causes a slight vacuum, bringing in outside air thru infiltration.  Because it does this, it may be 10% less efficient than the 84%.  It is possible to use the 80% boiler in a very small boiler room and have it draw its air from the outside to negate this effect.

    Some on this website will tell you that modcons are better because they can modulate down and burn at 25% of capacity and save you a bunch of money.  They do modulate, but so does a large capacity radiator system such as mine.  When it is, say 45-55 degrees, when modulation is needed, the large capacity system will never reach full operating temperature.  Radiators can take 160 degree plus water, but in warm weather, I doubt my radiators ever reach body temperature of 98f. 

    How large is your shop?  How many rooms?  How many floors?  Slab on grade?  Have you done a heat loss calculation?
  • RodmanRodman Member Posts: 9
    edited April 2013

    I re-read you post.  Your "shop" will be a lot like my home.  My home is 1200 basement and 2400 on two floors.  If you put a regular hot water heater in the basement with a 80% boiler, they will heat that lower level.  My basement comes out of the ground by about 3 feet on average, and when it was -17f a couple of years ago, it was 64f in my basement 1 foot above the floor (probably warm engough for a shop). With 2 inches of foam board on the basement, you have already heated your basement.

    I would also like to add that you do not want to use fiberglass insulation in your walls on the upper level.  Fiberglass is not very dense, so you therefore get a lot of air movement when you get below zero degrees.  Fiberglass R-rating is HALF value at -18f, which is common in your area.  Half means your bill doubles, as it did in mine comparing one winter with lows of 0f and another at -17f, in January.  Not happy.  Cellulose will maintain its R-value at any temperature you see in your locale.

    More important than all of the help you will get here, I would like to suggest how you construct your building.  Insulate the basement floor, and use all concrete construction.  I mean concrete basement wall (with 2" foam board on the exterior), and I also mean concrete first floor wall.  What are the advantages?

    1.  about as sound proof as can be

    2.  indestructible on the inside

    3.  if you put 2-4" of foamboard on the outside, and use dri-vit coating or other siding material, you have as large a heat sink as possible, and it is all inside of the space.  Where you don't want to use dri-vit, you can insulate the inside instead or sheath the insulation.  If you want indestructible on both sides, use insulated concrete panel for either the basement wall or the exterior wall or both.

    If you want to talk, send me your telephone number in private message, and I will call.

    You will also want to add an exterior door to your basement.  It makes access a whole lot easier.
  • RodmanRodman Member Posts: 9

    How you design the building is more important.  If you had a square building with 50' on a side, times 4 sides, times a 10 foot ceiling that is:

    50 x 4 = 200 x 10' ceiling = 2,000 sf of wall

    2,000 sf of wall plus 2,400 of ceiling = 4,400 ft of wall and ceiling

    If the average was an R-19, your u factor is .05 (about) x 4,400 sf wall=220 x 100 degree design temp equals a heat loss of only 22,000 btus per hour. 

    I would consider using a lot of skylights (on a flat roof), which will save you a whole bunch on lighting, but adds to security.  With all that and any adds you have, your total heat loss could be 50,000 btus per hour or less.  This is nothing.  My home, uninsulated as it is, with 600 sf of windows has a heat loss of 94,000 btus.

    If you target a 50,000 btu heat loss, you could use two or three of the smallest boilers burnham has, and never be without heat.  Further let me throw something else into the mix.  If you used cast iron baseboard (also indestructible in a shop, cast iron baseboard has 3.4 square feet of radiation per lineal foot.  At only 140f water temperature this is 3.4 x 200 (200 btus output per 3.4 lineal foot at 140f) this is 680 btus per lineal foot of baseboard.  50,000 btus per hour / 680= only 73 feet of baseboard.

    If you used radiators like my house has, a 26" high 4 tube radiator with 23 sections puts out a lot of heat.  Each section has 5 square feet of radiation, and at 140 degree water puts out 200 btuh per square foot.  That is 1,000 btus per hour per section.  This is 23,000 btus for one radiator.  The more radiators you add, the less your heat bill will be.  Buy six radiators and that would be 138,000 btus of radiation, and about 60 gallons of water.  The more mass, the less the gas bill.  6 radiators at 450 pound apiece plus 60 gallons (480 pounds) of water is 3,180 pounds radiating heat.

    My gas bill (related to heating only $783 annual) is all the proof you need.  Cast iron baseboard or cast iron radiators are also a lot more responsive than some other alternatives.  It is also safe in your shop environment.

    I have other ideas if you want to hear them.
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