steve burke
New Member
Posts:26
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| 02 Feb 2013 12:15 PM |
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I am building in Squaw Valley (aka Olympic Valley in Placer County, Ca) and plan for PEX radiant. We also plan for ICF though pricing may suggest we use stick.
We will be all electric since Squaw does not have natural gas. Propane is not an option as tank blowups occur around here and I certainly will not be shoveling a tank when we get 600-800" of snow. As a design note we are looking at 8 or 10" ICF on the ground floor, with 6" on upper two levels. Ground floor will be slab on 6" EPS.
That said, we plan for all electric, including in-line electric heat for radiant (yes, i know the amps). Any suggestions on makers of in-line electric heaters will be helpful. Also input as to whether we should separate the in-line electric for domestic H2O and radiant will be helpful.
The house plan calls for ICF (depending on price) with R50 roof. I would like to do the calculations (Thanks Robert Borsh for the calculator found elsewhere in this forum) for radiant but cannot find the "Design Outdoor Temperature." Can someone point me to where i can find the design temp for Squaw.
Also, please advise on who can provide a radiant design for the house (just in case my calculator breaks).
Thank you, Steve |
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sailawayrb
Veteran Member
Posts:2283
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| 02 Feb 2013 12:55 PM |
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Glad to hear that your found our DIY hydronic radiant design calculator to be helpful. The design outside temp is only used by our hydronic radiant design calculator to "correct" the exposed slab heat loss that you entered into the calculator and obtained by doing a standard building heat analysis (or by using our DIY heat loss calculator). The exposed slab heat loss value from a standard building heat loss analysis is typically based on the assumption that the slab will experience the difference between indoor temp and the outdoor temp. In reality, a hydronic heated floor slab will experience the difference between the higher heated slab temp and the outdoor temp, and hence the need for the design outdoor temp entry in our hydronic radiant design calculator to "correct" the exposed slab heat loss obtained from a standard building heat loss analysis. So please be sure to use the same design outdoor temp value that you used for your building heat loss analysis in our hydronic radiant heating calculator. Please also be reminded that our calculator is only valid for fully insultated 4" thick concrete slab-on-grade floors as stated in the instructions and it may not be valid for designing your upper level floors.
It seems like the Hydro Shark electric micro boilers are becoming more popular every day. These are dedicated hydronic heating ONLY boilers. There are some folks on this forum that don't think too highly of these boilers. While we have some concerns about how long these low mass boilers will live in this application, we don't have any field experience with using this boiler. So we really can't comment other than that they may be worth considering if you have completely ruled out propane. Why are propane tanks blowing up in your area? Seems like that concern/issue could be easily solved. You will certainly want to keep your domestic water and hydronic water separated, and there are several ways to successfully accomplish this. It sounds like you are interested in DIY hydronic design. If so, you might want to obtain a copy of Sieg's "Modern Hydronic Floor Heating" and spend some time studying it too. |
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| Borst Engineering & Construction LLC - Competence, Integrity and Professionalism are integral to all that we do! |
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steve burke
New Member
Posts:26
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| 02 Feb 2013 01:56 PM |
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Hi Sailawayrb (BTW we sail in Santa Cruz/Monterey Bay),
thanks for the comment but I am still trying to understand why the Outside Design Temperature in modeling our radiant systems is not required. I thought that this is an initial for heat loss calcs (saw this as one of the first inputs in the DIY Heat Loss Analysis) that are inputs elsewhere in your other models. BTW, we have no exterior slabs. For the time being, we are assuming the entire house envelope is R22 wall, and R50 Roof.
Good catch on slab thickness, our ground level is 5"...on this i can make a simple assumption that radiant PEX is at the same distance from living space (i.e. use standoffs when placing PEX as if i was using a 4" slab as far as the PEX position is concerned), and that the added concrete below the PEX is negligible given the 6" EPS below the slab -- not perfect but probably ok.
Apologies for being dense, but i can't connect the dots yet. Thanks, Steve
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ICFHybrid
Veteran Member
Posts:3039
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| 02 Feb 2013 02:22 PM |
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If that Squaw Valley build is for year-round occupancy, you might consider doing something more energy-efficient. Are your upper floors going to be concrete like QuadDeck or more conventional like wood joists? And why the radiant? |
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sailawayrb
Veteran Member
Posts:2283
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| 02 Feb 2013 02:30 PM |
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Hi Steve,
Exposed slab-on-grade means that you have an exposed slab-on-grade perimeter. Exposed perimeter means the floor perimeter is exposed to the outdoor temp...even if the slab is within the stem walls and even if there is perimeter insulation between the stem walls and the slab, which you would certainly want to have since the majority of heat loss is via the slab perimeter and not so much from below the central interior portion of slab.
The design outdoor temp IS REQUIRED...required for BOTH the heat loss analysis and the hydronic analysis for reason I previously described. Sometimes folks forget to factor into the analysis that the slab is warmer than room temp and they underestimate the exposed floor heat loss. The calculator properly address this and takes care of all the math. However, this is the only reason there is a design outdoor temp input entry in the hydronic calculator. Hope this explanation helps.
We were just in Monterey this week (Monday and Tuesday)...actually Carmel for a project. We enjoyed the low 60s and the sun while having lunch at Pebble Beach (Sticks). Then we returned to rainy Seattle late Tuesday night... Never sailed Monterey, but did sail Sea of Cortez (the Moorings out of La Paz) a couple years ago during February whale calving season. We have mostly sailed Puget Sound, Suan Juans, and Desolation Sound. We have also sailed the British Virgin Islands and Tonga. We will be in Maui in a couple weeks for a water work project and hopefully whale watching and some diving, but no sailing. Its all good!
Bob B. |
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| Borst Engineering & Construction LLC - Competence, Integrity and Professionalism are integral to all that we do! |
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Blueridgecompany.com
Advanced Member
Posts:656
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| 02 Feb 2013 03:04 PM |
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Electric Boiler with out door reset on a 5 inch slab is a good way to go. You will want multiple zones, upper and lower perhaps more. In your location the system will need to be glycol protected in the event of power outage. A simple back up generator will not do much with an electric boiler, typically residential electric units are running 18KW or more.
You might also confirm if a H stamp boiler (pressure vessel rated as a boiler) is required with your county.
One advantage electric boilers have over a propane condensing boiler that electric units are fairly basic and user friendly in design.
The part about the propane tanks blowing up, have never heard of this being a problem, perhaps it has to do with the installation?
If using an electric boiler it is not cost effective to use the same appliance for domestic hot water. Better to buy a 50 gallon electric water heater.isolated and 1/3 the cost, less to operate.
We offer prefabricated system with proper boilers (H stamp) that have out door reset built in to the boiler.
Good luck with your project,
Dan |
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| Dan <br>BlueRidgeCompany.com |
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steve burke
New Member
Posts:26
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| 02 Feb 2013 03:30 PM |
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Great input Dan, thank you.
we will go the route you suggest, i love simple design and no venting as with combusion appliances. we will use separate in-line heater for radiant, and separate in-line for domestic H2O heating.since this is seasonal use, i prefer not to store and heat hot water if no one is home. That said, please send me a PM and i can share our plans with you.
regarding propoane, it is not the install, it is maintenance. checkout this link http://lawreview.vermontlaw.edu/fil...-brown.pdf
while "rare" according propane industry, i hear about them in Tahoe annually -- just google it. That said, it is easier to just go all electric and eliminate the risk. |
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BadgerBoilerMN
Veteran Member
Posts:2010
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| 03 Feb 2013 12:01 PM |
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Propane boilers blow up around there?
First, a proper heat load analysis performed on dedicated software by an experienced radiant floor designer. All aspects of the design are thus covered, including the thickness of the slab, insulation, PEX spacing and design water temperature. The HydroShark is almost an exclusively DIY product, lacking what we feel are essential components including outdoor reset control (ODR).
When designing hydronic radiant floors or ceilings we specify (and install in our local market) more conventional and accepted electric boiler such as Argo, Electro,Thermolec and Slant-Fin's Monitron series depending on the local supply and support.
The standard for "efficient" electric water heating here in Minneapolis is the Marathon. I prefer to store my domestic hot water, efficiently, in almost every case. |
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| MA<br>www.badgerboilerservice.com |
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steve burke
New Member
Posts:26
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| 03 Feb 2013 12:36 PM |
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Hey Badger, this is really super advice.I will look up those you recommend and steer clear of Hydroshark. Thank you...now to try to do the calcs. |
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steve burke
New Member
Posts:26
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| 03 Feb 2013 12:42 PM |
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Badger, one other question to you...you mention "here in Minneapolis is the Marathon. I prefer to store my domestic hot water, efficiently, in almost every case."
How would you advise me for Squaw where this is more or less a weekend house? I would think that heating a bunch of water and leaving it for a week would be inefficient as compared with an inline heater. Will appreciate your, and others, perspective.
Thank you, Steve |
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BadgerBoilerMN
Veteran Member
Posts:2010
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| 03 Feb 2013 02:21 PM |
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Storage if a factor of temperature differential and cost of fuel. Electric tank-less water heaters are available and may be the answer if your water is not too hard. You will also need a lot of horsepower (amperage) to drive an an electric tank-less to drive a couple of showers or try to fill a tub. In most cases you are money ahead to store water in a well insulated tank if electricity is your only fuel. Half the country does it this way with a poorly insulated tank. |
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| MA<br>www.badgerboilerservice.com |
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acwizard
Basic Member
Posts:265
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| 04 Feb 2013 09:59 AM |
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I assume that you are building this home and building permits are going to be obtained.Here in California all structures must comply with Title 24. Using electric boilers or water heaters may not be allowed as your primary heating source. Squaw Valley is located in Climate Zone 16 per Title 24 and this zone will dictate the requirements needed to comply.Building a home in California has gotten complicated.You will need a registered engineer to run the energy calculations and stamp the drawings.If indeed electric is allowed if will have to be listed by the California Energy Commission and meet the Appliance Efficiency Regulations, Title 20. |
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steve burke
New Member
Posts:26
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| 04 Feb 2013 12:00 PM |
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AC Wizard..Yes to all of your post and i would not have it any other way, permit, follow title 24... That said, i will greatly appreciate the advice of this forum in systems and equipment that i should consider.
From the posts i hear that "the other half of the county uses hot water tanks instead of inline." That said, the traditional way is not always the best though you do have to appreciate the past to design for the future. i would like to understand the advice of others who know the best design and equipment whether they are used in this country, Japan or Europe.
Thanks again for your thoughts. |
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