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First home -- Where do I start with updating heating system and adding cooling?

kelchmkelchm Member Posts: 14
Hi All,

I'll be closing on my first house at the end of the month. I'm excited, but I feel like I'm going in circles trying to work out a plan for heating and cooling.

Things I know:
- Aprox. 3000sqft, four bedroom two bath home (it's basically a raised ranch with living space added to what would normally be the attic)
- Aprox. 1000sqft of unfinished space split between the basement and second floor
- The boiler is a 1977 oil fired Weil-McLain that is original to the house
- Hydronic baseboard convectors in all rooms
- At least 4 existing heating zones
- No central air, some small wall unit air conditioners
- The hot water heater is electric and is at least 30 years old (!!!)
- I have access to most rooms on the from the unfinished 'attic' on the second floor
- I have access to all rooms on the main level except for one from the basement
- The walkout basement has a good extra foot of headroom over typical basements
- Located in Central Pennsylvania, so we can get some decently cold weather

Things I need:
- Air conditioning!!!
- A hot water heater that isn't older than I am

Things I want:
- Even more zones (it's a huge house and some rooms will spend days or weeks mostly unoccupied)
- The ability to inexpensively expand both heating and cooling systems as I finish off additional interior space
- To be able to control heating and cooling without multiple thermostats per-zone
- The ability to tie everything in to home automation (I'm a software developer by trade)

Things that I wish I could do:
- Getting rid of at least some of the ugly baseboard convectors

I also have a number of general questions:
1. My assumption is that the boiler is rapidly approaching the end of it's life and that a modern replacement would likely pay for itself in terms of efficiency.
2. The hot water heater obviously needs to be replaced ASAP. Would it be foolish to install another electric water heater when I could do an indirect water heater in combination with a new boiler? How do I figure out which would cost less to operate? How do the hybrid heat-pump water heaters compare in terms of efficiency?
3. How blasphemous would it be to completely eliminate the hydronic heating and move to ducted multi-split systems? (FWIW, I've never had anything other than forced air so I have no idea what I'm missing)
4. How do I go about finding the right people to do the work the right way. IE: I want to find someone who will actually do the math and design an appropriate system to meet my needs, rather than just eyeballing it and throwing a system together.

Thanks,
Matt

Comments

  • lchmblchmb Member Posts: 2,872
    a lot of things possible... to start..do you wish to stay oil or is NG or propane something your interested in? An electric wh is a cheap purchase if the old one is questionable... I've heard mixed reviews from customer on the hybrids but a lot of them do like them.
    I think your best bet is to get someone (from this site would be a strong recommendation) who can look at everything you've got, do a heat loss of the building and give you all the options... then come back and put them on the table and see what the masses think...;)
  • HVACNUTHVACNUT Member Posts: 1,734
    Click on "find a contractor in my area" link to see if anyone can swing by, take calculations, check options for different applications, and write up a proposal.
    Be careful, some guys here will try to talk you into converting to steam.
  • STEVEusaPASTEVEusaPA Member Posts: 2,447
    edited May 2018
    It all starts with knowing all your options and a good design.
    Here's a top notch guy probably close to you..
    @Harvey Ramer
    https://heatinghelp.com/find-a-contractor/detail/ramer-mechanical-llc
    steve
  • SuperJSuperJ Member Posts: 354
    I wouldn't say your crazy for considering mini splits for your AC, the high efficiency ones are almost all heat pumps, but I would see that as a bonus (not as a hydronic replacement). If your floorplan is open enough to get away with 3 or less heads than then mini-splits for AC make a bunch of sense. They are basically the modcon of AC. You can get a pretty good turn down sometimes from 2500 - 12000 btu in a mini split, so it can keep running (dehum) even at light AC loads.

    I would keep the hydronic heat though as your primary heat source. It's so nice, especially if you get it configured for constant circulation (maybe aggressive OA reset with TRVs for high limiting). A constant warm comfort.

    I wouldn't spend the money on a heat pump water heater. The COP isn't high enough to justify the cost and complexity IMHO. And it sounds like the installing AC and upgrading your boiler is going to require some cash. Maybe consider an indirect tank if you do a boiler system upgrade.
  • GBartGBart Member Posts: 678
    edited May 2018
    Agree, get a indirect water heater, the boiler will probably be ok for now, Weil McLain is a good design cast iron and could last 100 years, and go ductless split heat pumps and only use the boiler when it's cold.

    and congratulations
  • BrewbeerBrewbeer Member Posts: 515
    Separate heating and cooling systems.

    Where are you located? e.g., how many days per year do you need heat, and how many days per year do you need cooling? For example, I live in western Mass, and need heat about 220 days per year, but only need cooling about 30 days per year. Therefore, I have much, much more invested in my heating system than my cooling system. I have a modcon boiler, ~130 feet of high output baseboard in my 2K sq.ft. split, in 3 zones. I use two, 8K BTU window shakers for cooling.
    Hydronics inspired homeowner with self-designed high efficiency low temperature baseboard system and professionally installed mod-con boiler with indirect DHW. My system design thread: http://forum.heatinghelp.com/discussion/154385
    System Photo: https://us.v-cdn.net/5021738/uploads/FileUpload/79/451e1f19a1e5b345e0951fbe1ff6ca.jpg
  • kelchmkelchm Member Posts: 14
    lchmb said:

    a lot of things possible... to start..do you wish to stay oil or is NG or propane something your interested in?

    Natural gas is not an option, but I have considered LP, primarily because I strongly prefer cooking with gas compared to electric. I'd want a 1000 gallon buried tank, which adds considerable expense.
    Steamhead said:

    kelchm said:


    3. How blasphemous would it be to completely eliminate the hydronic heating and move to ducted multi-split systems?

    That's called a Cardinal Sin.
    I figured as much. :D
    GBart said:

    Agree, get a indirect water heater, the boiler will probably be ok for now, Weil McLain is a good design cast iron and could last 100 years, and go ductless split heat pumps and only use the boiler when it's cold.

    Would an indirect make sense if I'm not actually replacing the boiler? I was under the impression that the efficiency of these older boilers is quite poor and using it DHW would exacerbate the issue.
    Brewbeer said:

    Separate heating and cooling systems.

    Where are you located? e.g., how many days per year do you need heat, and how many days per year do you need cooling? For example, I live in western Mass, and need heat about 220 days per year, but only need cooling about 30 days per year. Therefore, I have much, much more invested in my heating system than my cooling system. I have a modcon boiler, ~130 feet of high output baseboard in my 2K sq.ft. split, in 3 zones. I use two, 8K BTU window shakers for cooling.

    I'll be located in central PA (Carlisle, PA is about 30 minutes south.) I expect that AC would be used pretty consistently May through September. I also work from home, so having the house be comfortable even during the hottest part of the summer is essential.

    My main concern with having separate eating and cooling is the difficulty I'll have with needing to match up zones one to one (I don't want multiple thermostats per zone) and tying everything in to home automation.
  • BrewbeerBrewbeer Member Posts: 515
    There usually isn't a match between heating and cooling zone needs. For example in my house, my top level zone rarely needs heat during the winter, since the heat travels up the structure from lower down. I have no cooling whatsoever in the lower levels, as the cool air from the ACs installed in the bedrooms does a fine job sinking down through the house during the day. The zone that needs the most cooling (e.g., the highest level in the house), is not the same that needs the most heat (e.g., the lowest level in the house). A "manual J" calculation for your house is in order, that will tell you where your heating load and cooling loads need to be most appropriately focused.

    Regarding hot water, an indirect fired from your existing boiler would probably be more efficient than a stand-alone water heater, unless you purchase something fairly high-end.
    Hydronics inspired homeowner with self-designed high efficiency low temperature baseboard system and professionally installed mod-con boiler with indirect DHW. My system design thread: http://forum.heatinghelp.com/discussion/154385
    System Photo: https://us.v-cdn.net/5021738/uploads/FileUpload/79/451e1f19a1e5b345e0951fbe1ff6ca.jpg
  • Solid_Fuel_ManSolid_Fuel_Man Member Posts: 1,289
    What is your cost of electricity and of oil?
    Master electrician specialising in boiler and burner controls, multiple fuel systems, radiant system controls, building controls, and universal refrigeration tech.
  • EBEBRATT-EdEBEBRATT-Ed Member Posts: 4,755
    @kelchm
    I know your excited about being a homeowner. Congrats!!

    Don't go in too many directions at once.

    1. Step 1 is an accurate heat loss (heating) and heat gain (cooling) You can download the Slant Fin app and do your own heat loss. It's pretty easy. Heat gain is a different issue. Rule of thumb (which can't be trusted is cooling load is 1/2 of heating load) still need to calculate it.
    2. Propane is an option. Fuel oil is 140,000 btu/gallon, efficiency is about 83%. Propane is about 91,600 btu/gallon. Efficiency depends on the boiler you install. If you stay with hot water heat propane would be in the mid 80s efficiency wise so you can compare prices.
    3. I would keep the hot water heat and incorporate and indirect water heater an EK boiler would be a good choice. If you use ductless spilt heat pumps you will have a back-up source of heat and you don't need to cool the entire house if you don't need to.


    @Harvey Ramer would be excellent if you can get him
  • Robert_25Robert_25 Member Posts: 173
    Congratulations on your first home.

    I live in a 100+ year old home in Northern NY, and was faced with many of the same decisions as you. When we moved in, the house had a 1977 Weil McLain boiler, no AC, and a very high fuel bill.

    I ended up adding a Dakin minisplit for cooling, and heat in the shoulder season. The old Weil McLain is still running, with a new indirect for domestic hot water. I split the zones up a little, and added insulation to the attic.

    Now the house is cool and comfortable in the summer, we use just under 1 gallon of heating oil per day to make DHW for a family of 4, and the heating bill is about 25% less than when we started.
  • kelchmkelchm Member Posts: 14

    What is your cost of electricity and of oil?

    Good question. I'm actually not 100% sure yet.

    Based on my past experience, electricity should be around $0.07/kWh. I also know the current owner is baying around $3500/year for fuel oil, which seemed insanely high.
  • SuperTechSuperTech Member Posts: 549
    Get an Energy Kinetics boiler with the hot water storage tank. You will save quite a bit of oil. You can also use the same EK boiler with propane if you want, just have to change the burner.
  • Solid_Fuel_ManSolid_Fuel_Man Member Posts: 1,289
    With $0.07 a KWH oil equivalent is $2.30 a gallon assuming 80% real world efficiency of oil and 97% efficiency of electric.

    Check your electric bill and add in all the fees to see if you are actually paying more than that per actual KWH, or if those fees are always there then the $0.07 is a good number. Sometimes it's hard to beat an electric water heater as far as overall cost and longevity.
    Master electrician specialising in boiler and burner controls, multiple fuel systems, radiant system controls, building controls, and universal refrigeration tech.
  • Jon_blaneyJon_blaney Member Posts: 41
    But in the summer the efficiency of oil is more like 50% with a standard indirect.
  • Solid_Fuel_ManSolid_Fuel_Man Member Posts: 1,289
    With oil at 50% summertime efficiency, then electric at $0.07 per KWH is like $1.50 per gallon oil.

    If oil is more than $1.50 a gallon then electric resistance is cheaper at $0.07 a KWH.
    Master electrician specialising in boiler and burner controls, multiple fuel systems, radiant system controls, building controls, and universal refrigeration tech.
  • kelchmkelchm Member Posts: 14
    Just wanted to update this thread. I did end up purchasing the house and had @Harvey Ramer out to design a system for air conditioning.

    I'll likely try to limp along the existing boiler for another year or two if I can. Too many other things that need to be taken care of ASAP.
  • the_donutthe_donut Member Posts: 374
    Keep us updated. We like pictures and follow ups.
  • kelchmkelchm Member Posts: 14
    edited December 2018
    Just wanted to loop back on this thread with some photos and more information after living at in the house for the past 6 months. First, here are a couple photos of the house itself. It’s pretty unique, at least on the east coast. I’ve since figured out that the design seems to have been influenced by the architecture found in Sea Ranch, CA.




    Currently the total finished space is roughly 3000sqft, with another 1500sqft I plan to (eventually) finish split between the attic and basement. Having lived here for six months, I think one of the most pressing issues is the lack of air conditioning. I work from home and made due with 3 portable air conditioners this year, but it was barely addequate during the hottest part of the summer and very expensive. At the peak of the summer my electric usage was pushing 2500kWh even while being very conservative about running the AC and at times the temperature in my office was pushing 80F. For comparison, my electric usage this month is looking to be approximately 1200kWh. Unfortunately traditional window units aren’t a good match since all of my windows are either sliders or casements.

    So far I've gotten two estimates for multi-split systems. In both cases, these system would really only cover a couple key areas of the house -- the kitchen / dining room, the living room, the sun room and my home office (I work from home). Just to cover the currently finished space I'd need 9 indoor heads. Adding in the additional spaces I plan to finish adds at least two more.

    Of the two estimates, one was for a Daikin system, while the other was for a Mitsubishi system. The Mitsubishi system came in around 50% more expensive, but also with the promise that the line sets could be almost entirely hidden inside the walls. Both systems covered the same rooms -- the kitchen/dining room, the living room, the sun room and my home office (I work from home). From what I've gathered, Daikin and Mitsubishi both have good reputations and it's a bit of a tossup as to which system would be better in terms of performance and reliability.

    I also got an estimate for a Mitsubishi system with an air handler and ducting (in addition to covering the four previously mentioned rooms with wall mount units) for the bedrooms and bathrooms. This didn’t seem to be a good value considering that I’d also be sacrificing the fine grained zoning I get with having a unit in each room (other than the bathrooms).

    Here’s a floor plan I lifted from one of the heat load calcs. The second floor has only one finished room, which is my office.


    On the heating front, I’ve had my boiler serviced and the flue cleaned. The boiler seems to still have some more life left in it, but the chimney liner has begun to deteriorate and will eventually need to have a stainless steel liner added if I plan to continue using it. It seems like given the pricing of such a liner, this would be a good motivation to switch to a direct vent propane boiler.

    One oddity I’ve discovered so far with the heating system is with the zoning. I have 6 zones, but only four circulators. As things are currently configured, two of the zones (master bedroom and the sunroom) do not trigger on their associated circulator when calling for heat and instead only open a zone valve. In practice this means that those two rooms are always colder than the rest of the house no matter what the temperature is set to on their respective thermostats.

    Another oddity is that I’ve noticed the boiler short-cycling on occasion. What I mean by this is that after the boiler runs for a few minutes and turn off, but then fire back up less than a minute later. I’ve not had a chance to dig into this, but I’m wondering if it could be caused by inconsistent sizing of the existing zones. Is there any way to alleviate this by lowering the temperature at which the boiler will fire again?

    One thing I’ve been wondering about is how practical it would be to eventually match up the zoning between the multi split system and the boiler. Would it be possible to configure each indoor unit to call for it’s correlating hydronic heat from the boiler if the outdoor temperature drops bellow a certain threshold? I know this is possible with most modern thermomstats, but it seems like running a mini split from a thermostat isn’t well supported and generally compromises the performance of the mini split system.

    Lastly here are a couple shots from the utility room.






  • ratioratio Member Posts: 1,775
    IDK what style of mini split system you were looking at, but at least some of the Mitsubishi heads can be fitted with a secondary heat relay to allow the mini split to bring on the baseboard if necessary. This would ease integration of the two systems.
  • kelchmkelchm Member Posts: 14
    ratio said:

    IDK what style of mini split system you were looking at, but at least some of the Mitsubishi heads can be fitted with a secondary heat relay to allow the mini split to bring on the baseboard if necessary. This would ease integration of the two systems.

    Is this a common configuration? I saw this mentioned as an option in both the Mitsubishi and Daikin literature, but I’ve not seen this kind of configuration discussed much.

    Honestly I’d prefer using and Ecobee or something similar, but I’ve heard a number of people complain that using a thermostat with a mini split basically nerfs some of the performance of the system.

  • FredFred Member Posts: 7,362
    I don't know which direction the roof pitches face but the design certainly lends itself to some solar panels too.
  • kelchmkelchm Member Posts: 14
    Fred said:

    I don't know which direction the roof pitches face but the design certainly lends itself to some solar panels too.

    You’re correct on that. The roof is basically perfectly optimized for solar in terms of pitch and direction.

    It’s definitely on the list to happen eventually, but I want to get the some more cricitcal things taken care of first.
  • ratioratio Member Posts: 1,775
    I've installed them (well, a few Mitsubishi units on a single job) with electric radiant heat panels coupled with single-head mini splits. Don't have any real info about their performance other than they worked during commissioning and haven't had any callbacks that I know of. I believe they are an option on the multi-head VRF systems as well, but haven't yet had any installs with that configuration.

    The reason why mini split efficiency takes a nose dive when operated with a standard thermostat interface is due to the modulation that is possible when the system knows just how fast the space is losing heat. With the sensor, the controls can judge the performance of the system and call for more or less compressage from the outdoor unit, using just enough to keep the space temperature steady at setpoint. With a thermostat, all the controls know is that the space either needs heat or not. Since it can't tell how much, it ramps up to 'lots' in an attempt to avoid 'not enough'. It's forced to operate this way as modern electronic stats try to manage the heat loss as well, by cycling the heat call on and off over a period of time (as opposed to the old mechanical thermostats that basically just called for heat when the space cooled off). The long and short of it is that once two systems try to control the same variable (space temp), all bets are off as to how they'll interact. 'Emergent behavior' is I believe the current name for whatever might happen.

  • kelchmkelchm Member Posts: 14
    Decided to park myself in front of the boiler for a bit tonight to observe. Somewhat confused by the behavior I'm seeing.

    When I first sat down, the temperature gauge was reading 205ºF. Given the aquastat settings that seems like it shouldn't be possible. Any thoughts?


    My boiler has an indirect coil, but it's not currently being used (I have an electric water heater). Are there any optimizations I can make here given that I don't need to maintain boiler temp for DHW?
  • Solid_Fuel_ManSolid_Fuel_Man Member Posts: 1,289
    You can likely turn that low temp currently at 160 to 140 and the high currently at 180 to 170 or even 160 and see how things run.
    Master electrician specialising in boiler and burner controls, multiple fuel systems, radiant system controls, building controls, and universal refrigeration tech.
  • kelchmkelchm Member Posts: 14

    You can likely turn that low temp currently at 160 to 140 and the high currently at 180 to 170 or even 160 and see how things run.

    Thanks -- I've set the low to 140 and the high to 160. So far so good. The baseboards convectors are noticeably cooler to the touch while the circulators are on, but I've noticed very little difference otherwise. As a test I set the temperature back to 60ºF in the main zone last night and then bumped it up to 65ºF around 8AM this morning. As you can see, it still recovered very quickly. It's not terribly cold out right now (~35ºF), so I'll be keeping a close eye on performance once the temperature drops again.



    It logically makes sense that reducing the low setpoint reduces 'idle' fuel consumption, but are there any resources you can point me to that explain how reducing the high setpoint contributes to lower fuel usage?
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