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Radiant Floor Heat - Hydronic

I started on a radiant heat effort using Uponor's Wirsbo Quik Trak system with the ultimate goal installind throughout our house. Unfortunately, living in Virginia Hampton Roads region there is not a big (none) demand for this type heating nor contractors with experience or expertise to consult. I am now at a juncture a decision needs to be made on a heat source. My initial thought was to use a boiler, based on numerous sessions I watched on This Old House. Leveraging what help & guidance that is available (mainly plumbers) they’re advocating tank-less. This year I replaced our hot water heater, outside mounted tank-less, with the intent to use that space for the boiler. Now I am not sure adequate space exist for a boiler. House is a ranch, 2,700 sq ft with a ROG. At the sametime the carpeting is being replaced stone tile. I am struggling in getting a sound analysis to address all rooms, components needed (manifolds, etc) & loops. I am well aware the sizing will ultimately determine the heat source sizing (boiler or tank-less). I am under a time constant because my permit is close to end of term and I need to resolve/decide on a heat source. Anyone experienced in the area and would/can offer some advice?

Re: Radiant Floor Heat - Hydronic

My preference has always been for a boiler--modern boilers are 85% to 95% efficient & have enough heat output to allow options such as a radiant system, a baseboard system AND an indirect-fired 40 gallon hot water heater for all your domestic hot water needs---yet most of them these days are no larger than a large suitcase.

Wall-hung boilers have become the vogue if space is still a problem.

A radiant distribution system is more complicated than say a baseboard system (which is a good option)--but it's hard to believe that you haven't been able to find an experienced radiant tech in your area.

Have you tried across the bridge in Norfolk??

Try this; consult the Yellow Pages under "Heating Equipment-Parts & Supplies.

These are known as boiler supply & parts houses, meaning the COUNTERMAN in all these stores has daily contact with all the heating technicians in the area---call in the afternoon between 1 pm & 4 pm when it's not busy.

When the operator answer the phone, ask for the "parts counterman"---tell him your needs & ask for a referral of any radiant/hot water installers he knows in the area---he will probably take your phone # & call back after consulting with the other countermen in the shop.

If you call several parts houses, I'm sure you'll get some referrals.

You should get at least 4-6 estimates for the job---the price quote & selection of equipment will vary widely among the quotes.

Among the best boilers, I would include Burnham, Crown, Biasi, Viessmann, Dunkirk, Peerless, Slant/Fin, Triangle Tube, Utica, Weil McLain, & Buderus.

Even a basic cast iron boiler by an above mfgr for $1500 plus an install for radiant might result in a $7k to $8k price quote, if not higher.

The same boiler with a hot water baseboard install instead of radiant might quote for $4k to $5k.

A radiant install has a lot of additional components & increased labor in stringing the PEX tubing--it also works best with a high-end variable speed condensing boiler, providing the most efficient heating system that will save $$$ over a 5 to 10 year period---all this increases the upfront price quote.

A basic cast iron boiler plus a baseboard install is a much quicker install due to less labor---though not quite as fuel-efficient, this system makes sense if $$$ is tight or you intend to relocate to another house within 5 years.

An outdoor reset (ODR) option on all these systems has become a standard install practice and will save a lot of fuel dollars in Virginia where there are fewer sub-freezing winter days.

Re: Radiant Floor Heat - Hydronic

Thanks for the awesome information and insight. I would like to clarify several items I failed to clearly communicate in my prior comments; 1) I live on the Norfolk side (Suffolk)- Hampton Roads is just a local term used for the local area which encompasses both sides of the water, 2) I am doing the plex-tubing installation and if I read your comments correctly costs noted include installation of the plex-tubing, 3) my greater need is selecting the heat source; your comments boilers are the way to go, I being living here long-term - unless some happens beyond my control ( well if my wife has her way) , 4) one item I really need your insight on is the overall analysis for heat source and loops per room sizing , 5) I would like to understand better as well available resources to research on ODR options, and 6) I have several rooms (bathrooms) already tiled and interested on your thoughts -installation of the plex between the floor joist (underside of the subfloor)- not sure I am ready to remove a tile floor that is in good condition.

Re: Radiant Floor Heat - Hydronic

You didn't mention your fuel supply--if it's other than NG or propane please advise.

I get the impression that you're doing this by yourself without any help.

This can be a daunting task in view of the plethora of different parts, components and design skills that are often needed to get a workable system.

Some diy'rs contract with a heating contractor to string the PEX & components under his supervision so that it's done right the first time---the labor & expense done by the homeowner is then deducted from the installation cost.

By all means, Google something like "radiant forums" to get a back & forth dialogue with others who are doing the same type of install.

The standard boiler for radiant is a gas-fired/propane-fired modulating condensing unit.

There is a long list of "energy star" boilers, both condensing & non-condensing at the "energy star" site below---some of the European units such as Viessmann and Buderus are expensive (but both excellent) due to the exhange rate of the Euro & the Dollar.

There are good condensing units by Triangle Tube Prestige, wall-hung, gas-fired, stainless steel heat exchanger & they also make an excellent stainless steel Triangle Tube Phase III indirect hot water heater.

Peerless Pinnacle gas-fired condensing boiler with stainless steel heat exchanger.

Dunkirk Qantum condensing gas-fired stainless steel heat exchanger.
Utica UB condensing gas-fired stainless steel heat exchanger.

Lochinvar Knight condensing gas-fired, stainless steel heat exchanger plus a good stainless steel Squire indirect hot water heater.

Viessmann Vitodens 100 condensing, gas-fired stainless steel heat exchanger.

It's important to establish that parts for whatever boiler you choose are available in the parts houses in your area; otherwise you could lose your heat for days while the part is shipped in from a distant distributor.

It should be noted that in relatively milder climates like Viginia, radiant heat is often powered by high output hot water heaters (Polaris, Triangle Tube & others) or rooftop solar panels.

These options are covered in the free radiant installation manuals---hot water heaters tend to break down within 5 years if used for radiant---solar panels are getting very popular & they qualify for a reimbursement from the feds.

Some condensing boilers have an aluminum heat exchanger---these react with a hard water supply & shorten the life of the heat exchanger.

Outdoor reset units may not give you the savings with a condensing unit, as they would with other boilers---they can always be installed at a later date---Tekmar units seem to be the most popular & have a good reputation.

Bathrooms are routinely done with sub-floor staple-up PEX---am I right to assume you are doing staple-up for most of the house??

Some PEX guidelines are not to exceed 300' for each loop for 1/2" PEX and not to exceed 400' for 7/8" PEX---all loops should be approx. the same length to provide balance to the system (water flowing thru piping has a mind of its own---it will always find the shortest length of pipe to go through in order to get back to the pump with the least amount of resistance as possible).

If not done yet, you should do a HEAT LOSS CALCULATION for each room for which you are installing your PEX---basic rules of thumb say that each ft. of 1/2" PEX puts out 25-40 btu/sq.ft, depending on the PEX spacing & floor material at staple-up--a single row of 7/8" PEX can be used for each joist cavity for a slightly higher output.

A very rough estimate of heat loss for a room is to multiply the square footage of the room by 35-40 (assuming 8' ceilings) ---the heat loss from the warm air inside the building exiting to the outside has to be equalled or exceeded by the output of the PEX-heated flooring.

The "house needs" site below has more tidbits on this subject--the free Slant/Fin heat loss calculator MUST BE DONE FOR EACH ROOM so you know what your heat loss is---it varies widely from room to room & building to building.

More PEX lines are stapled up (and closer together) around outside wall perimeters, especially under picture windows, windows, doors, etc. in order to offset the cold air and cold spots being produced by these fixtures.

There are tons of sites on the internet that explain & support diy sub-floor radiant heat--but it's tough to wade thru the waterfall of info.

Google "underfloor diy radiant heat" (without the quotes) or "dry system diy radiant heat" (without quotes) to get a bunch of sites.

An excellent book at the public library (free of charge) called "Modern Hydronic Heating", 2nd edition by John Siegenthaler is an easy read & is packed with lots of info.

Free installation manuals are available from Radiant Floor Co and Radiantec, both of these are in Vermont---there's no obligation to buy anything from these companies; although thin, the manuals are packed with lots of info---sites below.


Re: Radiant Floor Heat - Hydronic

Sorry for the delay and not responding sooner - work has kept me busy. I am glad and thankful to still be employed considering and seeing how many that have been displaced. Believe me we know our youngest was displaced in Sept and now we're left supporting him; thankfully he not married and/or has a family to support as well.
• Fuel source is gas
• Both my wife and I are very much into being dyi individuals (out -growth of my 22 yrs the Navy (retired in 1994), both (most of our spare time) active volunteers; wife animal rescue / Humane Society / local city animal shelter (primary reason behind this project - heat and tiling - not all dogs have been house trained as others) and for me it's Habitat for Humanity (recently - Sept 08 - finished leading a local build here in Suffolk, VA - waiting the start of next build locally) and what's left of my spare time it's tied to this project and helping my wife with her passion.
• It was thought (my mistake in thinking so) my youngest, who's a HVAC mechanic, the company he was working for when the effort was started would be the used as my contractor but as the economy changed so did my son's employment status...So that contractor relationship is now behind us and I must continue forward. It can to light I possess more knowledge and understand then what advice being provided. Actually I was hoping to do as you note; I do the labor and they oversee the effort. Side note: that company ended up being bought out.
• Initially (Oct 07) I purchased a quote through PlexSupply.com. It's based on using Uponor (Wirsbo) produces. Their concept - residential - is running/placing the tubing (5/16") in tracks (Quik Trak panels) with loops (runs) that are no longer than 250 feet. Over the tubing/panels (in my case) 1/8 cement board installed then the tile installed. If it's helpful I can send (if feasible) you the quote PlexSupply.com completed - which appears I will end going back to them to re-do/update adding the other rooms not in the original quote.
• With all the provided information and web sites I am sure it will take several weeks to review and research (I will be busy that's for sure).
• I had considered solar (consider is all it was) but since I am not a millionaire and not politically positioned in getting or finding an in getting a grant (us everyday individuals who end up carrying the institutions who continue to be the recipients of what available grants exist - which I am sure there are many who could afford to fund without the grants) are fortunate and lucky we're able to come in contact with willing and awesome individual like you who openly and graciously give of themselves in blessing others with their knowledge and gift.

I am off to start my research for several days!!! Thanks for all your insight and direction. I'll be back!!!!!

Re: Radiant Floor Heat - Hydroponic

You have some excellent advice in the replys you have received. This is my experience . I used the Radiantec site for my initial advice. They gave me a floor layout which I modified somewhat to maintain a 300' loop. They also calculated the heat loss. I have mine installed in a concrete slab. I installed the Pex myself. The only change I would have made would be to install the manifolds on the wall. I had the same problem with heating contractors but eventually found one. Hope this is going in the basement as the piping can take up some wall space in a utility room (like mine). My boiler is an electric Argo as my home is all electric. This has 4 elements that come on one at a time as more heat is needed. I can't heat my hot water with it because of code restrictions. Approx. cost $4500 materials and labor, Pex and manifolds extra. My electric bill for a 1200 sq.ft. home this Feb. (average temp. 17 degrees and I'm in an open field with no landscaping yet) was $347. Hope this helps you. You're gonna love in floor heat once you're up and running.

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