Radiant heat under carpeting

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Old 01-08-07, 02:46 PM
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Radiant heat under carpeting

I am considering change my current heating system from forced hot air to hot water radiant heat. I currently live is an 1800 sq ft ranch in southern New York State. I have hardwood floors throughout, except in the master bedroom, which is carpeted. Does anyone have any experience with the result of laying radiant heat tubing under the floors that are carpeted? Any opinions are the matter are appreciated.
 
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Old 01-08-07, 03:14 PM
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Radiant under carpet

I'm no radiant expert by any means but I do know the carpet & in particular the pad can severly inhibit radiants capabilities.
 
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Old 01-08-07, 04:20 PM
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The type and density of both the carpet and the pad are important when going radiant. Some are better than others.

A more important factor is probably how are you planning to run the tubing for this retrofit installation? Retrofit radiant is rarely as energy efficient, cost saving or responsive as original installations. Radiant systems, by their very nature, are slow responding but a retrofit where the heat source (tubing) is mounted underneath the subfloor (often in a basement or crawl space) is vastly inferior to a system that has the tubing directly under the finish flooring or embedded into a heatsink material.

What is your reason for wanting to retrofit?
 
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Old 01-08-07, 04:42 PM
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What about panel rads with TRVs under the windows for the bedrooms?
 
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Old 01-08-07, 05:40 PM
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I'll go with not so negative an impression as furd regarding efficiency of a retrofit radiant. A good staple-up system with quality extruded plates has decent efficiency. Most all such installs max out at <140F supply temp, which coupled with a condensing or modulating/condensing boiler would lead to some pretty high efficiencies.

As mentioned, carpet is a tough nut to crack. Who seems very fond this week of suggesting panel radiators with thermostatic radiator valves. I'll second that. If you size the panel rads to operate at the same water temperature as the radiant, that makes for a pretty simple system.

I would also second furd's question about the reason for going radiant. If you're looking for improved comfort over forced air, you could do very well for likely a lot less money going with panel radiators (with TRVs). In a full-basement ranch, a panel rad system would be pretty easy to pipe. The TRVs would give you control of heat in each room and basically cut out the need for zoning.
 
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Old 01-08-07, 08:25 PM
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Thanks to all replies. Here are more details of my situation:

I have a 35 year old house with what I believe is the original furnace. It is working reliably right now, but I'd rather be proactive and not wait till the thing craps-out one cold winter's night. I'm in the process of finishing my basement, so while I still have the ceilings open, I thought this would be a good time to uprade my heating system. I'm very unhappy with the drying effect of the forced hot air. Also, not zoned right now and seems hard to zone . So, if I'm going to upgrade, I thought I'd go to a gas-fired hot water system. I called 2 plumbers: One suggested baseboard heat (Hayden #750). The other suggested either baseboard (Slant/Fin) or radiant. I'd heard that radiant heat was very comfortable and could be set at lower temperatures (thus more energy efficient). Also, I thought my wife would also like the idea of the clean look of not using baseboard units on the main level--similar to what we have now (though we'll probably go with baseboard in the basement).

As I said, the basement ceiling joists are exposed. However, the master bedroom is in the garage, so I'd have to rip out the ceiling and insulation in there, which I would only consider doing if radiant made sense under the carpeting.

Anyway, that's the "why" of the matter. I'm not married to the idea of radiant, but I thought it was a reasonable consideration. Again, any opinions based on the new info are appreciated. By the way, could someone provide a good link for panel radiators/TRV systems?
 
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Old 01-09-07, 06:51 AM
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Underfloor heating with carpet on top is tough. You have to super insulate the joist cavities so that the heat gets stopped from going downwards and the R value of the carpeting and pad would be far better if they were working for the heating system than working against the heating system. It is much easier using radiant for smooth flooring surfaces, than having to use high temps to force it through carpet. Radiant ceilings work well with carpet however.

For pictures of panels use Google images and search on "panel rads". Same deal for TRVs, seach on "TRV". The nice part about the TRVs is that they allow each bedroom to be controlled individually - although the max is controlled by the t-stat - wherever it is. TRVs have no electrical parts. All you would need to run to the bedrooms are a supply and return pipe. These could be iron, copper or PEX - lots of piping options depending on access and expansion concerns.

The underfloor radiant is a good idea where you have good access. Ideally there aren't three million nails sticking out the bottom of the subfloor or those will all have to be removed if you want to put in radiant.

Before doing any serious thinking about radiant, it is imperative that you know your heatloss. For example, suppose your kitchen has a heatloss of 4,000btu/hr at design conditions. If you measure the floor area that you can heat (don't run it under cabinets and fridges) and find that you only have have 100 square feet then you'd be looking at 40btu/sf. That would actually be too high because with a target temperature of 70, you'd need 90 degree floors to heat the kitchen and that wouldn't be comfortable for the feet after the first few minutes of bliss.

If you are going with a gas modcon boiler, my approach would be the following:

1. do the room by room heatloss
(slantfin has free software - check heatinghelp dot com)
2. use pex and plates at 8" OC when doing floor heat using the slantfin s/w
(the plates aren't cheap, but this is the best if you must be underfloor)
3. see how low you can do the water temp for these radiant circuits
(don't rule out radiant walls or ceilings if that would work better)
4. size the panels for the non-radiant rooms based on the the temps for step3

This would result in a one temperature system (your boiler will be as efficient as the highest temp circuit in a multi-temp system) that could all just run off a manifold.

This whole thing could be driven by one circ - pipe the boiler to some manifolds and home run every bit of heating. The only other thing you'd need is a differential bypass ($50?) for when a bunch of TRVs are closed and you'd be set. Manifolds are expensive, but they are well engineered.

If funds were tight you could also do the same as above except for #4 do fintube, but do it so that as time goes on you could swap it out for panels if you want. Or even mix. With the manifolds, you can balance flows.
 
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Old 01-09-07, 08:32 AM
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Who is right on the money.

In your situation, I would go with panel radiators and TRVs. Given the poor access over the garage, and the possibility of having to spend a bunch of time cutting three million flooring nails, I'd say unless you have a burning desire for radiant then go with panel radiators. They'd be the next step up from baseboard and IMHO are more attractive than the long runs of baseboard that populate my house. Check out www.buderus.net, www.mysoninc.com, for some ideas in addition to the google search.

I would size the panel radiators so that a supply water temperature of about 150F would be needed on a "design" day (coldest outdoor temperature for your area, used in the heat loss calculations). This would keep you in the condensing range about 99.6% of the heating season and result in some very good boiler efficiencies.
 
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Old 01-09-07, 12:21 PM
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Retrofitting an existing heating system to a different type is rarely cost effective. If you are troubled by "dry air" then you need to add a humidifier to your system. Replacing your aging forced-air furnace, even with a modern two-stage condensing furnace will be far, far less expensive than starting from scratch and installing hydronic heat. The two-stage furnace with a suitable humidifier will go a long way to increasing your comfort level and quite likely show a deecrease in operating cost. The addition of the condensing feature (90+% AFUE rating) will significantly lower your fuel consumption.

As for my "negativity", xiphias would do well to remember that it was less than a year ago that he was the one asking questions rather than giving advice. He was the one having problems with his heating system being noisy and unable to keep the air out of the piping. At that time he was under the impression that only a major repipe of his system might allieviate his problems. I suggested that he simply move the point of connection of his expansion tank to prior to the suction of his circulator. His response after following my advice was:

"and the answer is...
PUMP AWAY FROM THE EXPANSION TANK CONNECTION. A good purge helps, too.

We left the circulator on the return. We moved the expansion tank connection from the discharge side of the circulator to the inlet side. A MUCH easier job than trying to move everything around on the supply side.

One good purge later, this system is silent.

Pumping away from the expansion tank just completely changes the way pressure operates through the heating system. I reiterate the earlier suggestion to check out the article by Mark Eatherton and the book by Dan Holohan suggested above.

In looking back through this looonnngg thread, I noticed that early on, Chimney Cricket called it when he said to check for "pumping away." Unfortunately, at the time I was basically clueless about what he was talking about and the way he described it didn't sound like that applied to my system. The things you learn....

Also interesting that at least four professionals (three plumbers and one hydronics design guy) stared at and/or worked on this system and nobody said anything about how the circ and tank were set up in relation to each other. One guy eventually did, but he would have moved the circ (major surgery relative to moving just the tank) rather than reposition the tank connection.

Having read all about pumping away and how it changes the pressure characteristics of the system, it is really cool to see that play out in my system. Every single problem we've had has disappeared. There's something to this physics stuff.

FWIW, the Taco 007 is one heck of a pump. The 2nd floor loop has a Total Equivalent Length (TEL) of around 324 ft. That's long. But the pump is pushing 3.95 gpm (probably more) through this loop. It is also fine with both zones (and the indirect as well) open. Right around 4 gpm everywhere. Cool.

Many thanks to everyone for sticking with this. I trust we've all learned something. I sure have!"


I guess my thirty-plus years in designing and operating steam and hot water heating systems (albeit commercial and industrial systems) doesn't mean much when stacked up against the experiences and self-education of some of the "experts" here. Thank you for reminding me why I stopped offering any advice on this forum.
 
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Old 01-09-07, 12:53 PM
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apology

Furd, absolutely no disrespect intended. You are indeed one of the reasons I like hanging out here, and in fact was wondering if you were still hanging out here at all. Your experience and insight is highly valued, and not just by me. I can recall at least a couple of posts where you offered some really fine thinking to people and I chimed in with all of "wow, you rock" or "what a cool post" or words to that effect.

In a year of learning, cogitating, and asking and looking around, I've learned a little. I try to stay within what I know or can reasonably learn about. I'm no expert and don't claim to be. Elsewhere on this forum I've described myself variously as a "hobbyist" and "hydronic wannabe."

In this particular instance, a friend of a colleague has a very nice-performing staple-up radiant retrofit. Runs almost entirely on solar with a 600 gallon tank. Pretty neat. Suggests to me that it can be done.

I view all this forum stuff as a discussion, and I certainly like to think I wouldn't say anything in a post that I wouldn't say in a discussion over a few beers. My take on your comment was that a radiant retrofit is far more hassle and expense than it's worth. My view is slightly different (based on n=1 direct experiences, a bunch of outside reading, and my own thinking about whether I'd ever consider ripping open my house just for warm feet, a ridiculously long payback time, and a few "environmental virtue" points [answer is unequivocally no]). Thought I'd share that.

If the original problem is really more of the dry air thing, and it could be solved by a new, more efficient furnace and humidification, then that's cool and something for the original poster to consider. Also something about which I know even less than hydronics.

Bottom line is that I'm sorry you took offense, none was intended, and please do stick around. You raise everybody up.
 
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Old 01-09-07, 01:20 PM
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I accept your apology.

I did not state, or at least did not intend to state, that below subfloor retrofits converting to radiant floor heating don't work. Most assuredly they do work but they will NOT work to the same degree of efficacy or efficiency as a system that is either directly under the finished floor or embedded into a thermal mass. A system retrofitted under a subfloor will indeed require a higher loop temperature to obtain the required surface temperature on the finished floor. This fact translates to a lower overall efficiency than would be the case if the radiant floor was done with either upper surface or embedded technology.

In the case of the original poster, if he is really interested in going radiant, and there are many reasons to do so other than saving money on operation, then I would likely suggest that he consider removing the existing carpeting and installing WarmBoard (or equivalent) and then replacing the carpeting. This would be a far better system (efficiency and efficacy wise) than running tubing under the subfloor.

My original comments were to point out that energy saving retrofits to existing structures often do not have a reasonable payback. Certainly there are some retrofits that make great sense and have rapid paybacks but wholesale replacement of a heating system is rarely one of them.
 
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Old 01-09-07, 01:25 PM
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Insert sound of handshake here.
 
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Old 01-09-07, 01:43 PM
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Furd

"I guess my thirty-plus years in designing and operating steam and hot water heating systems (albeit commercial and industrial systems) doesn't mean much when stacked up against the experiences and self-education of some of the "experts" here. Thank you for reminding me why I stopped offering any advice on this forum."

You're dealing with a bunch of well-meaning folks here that have tried to figure out our own heating systems. In the course of doing so we have lost sight of our own small systems and have become foamy mouthed hydronics junkies. We try to make up for having a ton of what would otherwise be totally trivial information by offering it to whoever shows up here. We appreciated the help we get when we were completely clueless and now we try to help out others by passing on any knowledge that we have gathered along the way.

Everyone of us fmhj's considers it a true priviledge that we also have seasoned pros in here that have seen and worked on far far more systems than we'll ever see in our lives.
 
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Old 01-09-07, 03:52 PM
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Who, you made some excellent points with your post on radiant panels. I like radiant panels (although not as much as radiant floors) but they have some of the same downsides as do convector baseboards, namely that some people (often women) object to them because they limit furniture placement. A room in which radiant panels are installed may have much of their functionality decreased if large pieces of furniture are placed in a manner to obscure the radiant panel.

Of course baseboard convectors are probably the worst offenders of "screwing up the wall space" as my dear (former) wife always said. The nice thing about a properly engineered radiant floor is that it is almost impossible to pile enough furniture on the floor to have a major reduction in the heat output of the floor.

I don't care much for forced air heating systems. My current house has a forced air system and I thought hard about retrofitting to radiant floors when I needed to replace the furnace. In my area (I live just north of Seattle WA.) the heating season is relatively mild which translates into relatively low operating costs. Having a two-stage 80% AFUE furnace installed was less than $3,000. Going to a 90+% AFUE would have required about ten years to break even. Making a change to radiant floors would have cost at a minimum $6,000 and a more reasonable figure would probably be closer to $9,000 in my particular instance. The payback, even time to amortize that cost would have been measured in several decades, if indeed there was any economical payback.

When I working, payback, or even just amortization, was a critical part of all projects. It is hard for me to get that concept out of my head. There are lots of "cool" ideas and I would like to see them through as much as anybody but as much as we hate to admit it money IS important and it does make the world go round. The most efficient system in the world is no bargain if it costs more to install and maintain than a less efficient system.
 
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Old 01-09-07, 03:53 PM
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So true it's funny. FMHJ indeed. Can I change my username?
 
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Old 01-09-07, 10:27 PM
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"Of course baseboard convectors are probably the worst offenders of "screwing up the wall space" as my dear (former) wife always said. The nice thing about a properly engineered radiant floor is that it is almost impossible to pile enough furniture on the floor to have a major reduction in the heat output of the floor."

Meanwhile the last exposed 12 square feet are 97F. It sounds like she'd be best off with radiant ceilings.
 
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Old 01-10-07, 10:02 AM
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Thanks for all the insights. I appreciate the discussions on break-even time given any improved efficiency with radiant. As a follow-up to that, does anyone have a sense how a radiant system (with near room-to-room temperature controls) would add to the resale value of a home versus a new, humidified, 2-stage forced hot air system with 2 zones?

Furd,
How many zones do you have in your system?
 
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Old 01-10-07, 10:42 AM
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It depends on the market. That includes how your realtor presents it, how the would-be buyer sees it and the value of the home relative to other homes in your area. It's only one of many aspects and every buyer looks at different things. Some people just care how good it looks from the front. Other people care more about the schools. You can put in a spectacular new kitchen, sell the house and find out the new buyer replaced it all in the first year.

Here in the Toronto area, many many many people would probably place better value on a furnace. They simply don't understand boilers. They think that a/c should come out of floor ducts. They fear leaks. They see the furnace as something you never have to touch until it breaks. Many don't even change the filters. They see a boiler, they see the valves, they cringe. This is the land of forced air gas heating. When I bought my house, a major feature WAS that it had a boiler. Every buyer is different. Paint and landscaping sometimes seem like the only home improvements that pay off when you sell.
 
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Old 01-10-07, 03:41 PM
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Who hits it dead-on when trying to determine what "value" something might have when selling your home. I don't have much personal experience in buying and selling homes but I do have a few contacts in the RE industry. By and large people pay scant attention to the mechanical systems in a house. A house needs a heating system, if it has one, fine. The type is rarely considered by the buyer although there certainy are exceptions to the norm.

As for my own house...it is a smaller (1550 square feet) one-level home built over a crawl space. The furnace is rated at 60,000BTU input on the second stage and about 40,000BTU input on the first stage. During normal operation, i.e. simply maintaining the set temperature in the house, it never goes to the second stage, even with outside temperatures in the teens. In the week prior to Christmas we had a massive windstorm in western Washington and lower than normal temperatures. My power was out for 54 hours (almost to the minute) and the inside temperature dropped to about 47 degrees with an outside temperature during the day of about 34 and night temperature in the mid 20's. When the power came back on I started the furnace, approximately three hours later the inside temperature was up to 65 degrees and the furnace was still running on the second stage.

I have only one zone in my house, because of its size zoning doesn't make much sense even though I live alone. Professionally speaking, I don't like zoning for forced air residential systems. Zoning of forced air residential systems usually creates more problems than it cures. Zoning of commercial / industrial (my area of expertise) forced air systems is totally different from residential and makes a great deal of sense.

Tell my why you are considering zoning in your home and what the size of your home is. Also relate the lifestyles of the people living in your home, i.e. is everybody gone duriing the day, the home is large and many of the rooms are not used and that kind of stuff and I may have some suggestions.
 
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Old 01-10-07, 04:08 PM
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Furd,

I have an 1800 square foot ranch. The bedrooms (3) are on one side of my house, with the living space (large L-shaped living room/dining room, and separate kitchen) on the other. I'd like to be able to turn the heat way down in the living space at night and in the bedrooms during the day. Also, ideally I'd like to be able to effectively control the heat in the basement, since my 2 young children (a one year old, and 3 1/2 year old) will be using that as their main play area.

Currently, I limit heat to the unused rooms by closing the vents. Seems that may make the furnace run even harder if the open vents are the ones far from the thermostat. Also, for the basement, I suppose I can cut vents into the existing ductwork, but I'd have to heat the whole house if the kids are cold in the basement.

Thanks
 
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Old 01-10-07, 05:24 PM
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Gaetanol, unless you are in a large multi-winged home, I really think that the key advantages to zoning are more for keeping things in balance than permanently trying to keep different parts of the house out of balance and always fluctuating.

I would really try and strive for balance within the system. If your home is fairly tight and properly insulated then it is going to be very tough to maintain very much in the way of different temps. Houses aren't typically insulated very much internally for internal climate zones. If your house does leak heat at a high enough rate that this kind of zoning would work, then better exterior insulation would be a better investment than trying to just heat what you need for the moment. It takes quite a while for the temperature in a house to stabilize - I can tell when the temperature here is using setback and when it has been fixed for a couple of days. It's noticeably more comfortable when everything stabilizes.

I find that the more I swing the temperatures in my own home, the more I start to only get comfortable at temperatures that are higher than I would normally use. Just some food for thought with the key being, if you can save much energy zoning like that, you'd be better off investing it in insulation.
 
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Old 01-10-07, 08:30 PM
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Wise advice from Who.

Gaetanol, your house is only slightly larger than mine (not counting the basement) and of a similar floor plan. While I understand your reasoning for wanting to zone the heating system I can almost guarantee that there is no positive economic return in doing so. For the moment I will ignore the basement and state that a two-stage furnace with variable speed blower and a properly sized humidifier will make your entire house much more comfortable and also significantly lower your fuel consumption. In your location a 90+% AFUE furnace may make a great deal of sense and would further reduce your fuel consumption. You need to run the numbers on lower fuel consumption vs. the higher cost of the 90+% unit. One thing that I would strongly suggest is that the entire distribution system (ductwork) be inspected for leaks and proper sizing along with necessary repairs and a final whole-house balancing of the airflow. This whole-house balancing will in most cases provide better comfort than will zoning.

You may also need to tighten up your building envelope with tighter windows, weatherstripping, insulation and sealing points of air infiltration. A full blown energy audit, including a blower door test is in order. Remember as Xiphias often points out, "Insulation is fuel you buy only once" when trying to determine the payback from tightening your building envelope.

On the other hand, don't go hog-wild in purchasing / installing every energy-saving device on the market. Retrofitting a home for energy saving can very quickly go from saving money on reduced fuel consumption to wasting money in ways that have extremely long or no payback.


As for your basement...if your basement is not currently being heated then it is quite likely that your furnace does not have enough capacity to allow for also heating the basement. If you were to attempt to heat your basement from your existing (or a similarly sized new) furnace you will be sorely disappointed. Although I dislike the current trend to installing additional heating units for separate floors this may be the best way to deal with your situation.
 
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Old 01-11-07, 01:44 PM
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Originally Posted by furd View Post
As for your basement...if your basement is not currently being heated then it is quite likely that your furnace does not have enough capacity to allow for also heating the basement. If you were to attempt to heat your basement from your existing (or a similarly sized new) furnace you will be sorely disappointed. Although I dislike the current trend to installing additional heating units for separate floors this may be the best way to deal with your situation.
Furd (and other generouos contributors),

Regarding my basement, I assume that if I upgrade the furnace, that I should have suffiecient BTUs to heat the basement along with the rest of the house. I don't imagine I'd go with a new unit that is sized as my current unit. What do you mean by "additional heating units?" Do you mean space heaters for the basement?

By the way, would your opinions change if we were planning expansion of the house? Small ranches in my area are being bought by builders to be razed so that large colonials can be built. Prices are stunning. We don't really want to move, and there likely would be good return on our investment if we were to invest in expanding our home--definately an enlarged kitchen, and perhaps even a second floor.

I very much appreciate your insights.
 
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Old 01-11-07, 02:27 PM
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GaetanoL, what is the average temp in your basement on a nice winter day? Is it insulated?
 
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Old 01-11-07, 02:56 PM
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The basement is currently not insulated, but it will be with R-15 (I'm in the process of finishing the basement). In fact, that's how this line of thought all started. Something like, "Gee, while I still have the ceilings open, I wonder if I should do something with the heating system).

Not sure how cold the basement currently gets on a cold. Not too cold for me to putz around down there if I wear a sweatshirt, but definately too cold for the kids to play down there.
 
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Old 01-11-07, 03:23 PM
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Although the clothing measurement is tried and true those thermometer thingees actually give numbers. ;-)

I'm impressed with just R5. I kept stalling on insulating a heated and conditioned crawlspace. It was always in balance with the house. Now it's absolutely balmy! maybe even too balmy... and one rad is disabled and may remain so... LOL

That unbroken layer of R5 XPS is probably more than equal to the crap R11 or whatever FG insulation is in my walls upstairs. Insulation is all about balance... no matter what I do in the rest of the house, until I rip drywall out upstairs... Woops - I'm getting started. ;-)
 
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Old 01-11-07, 04:45 PM
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Basement temperature

I have a thermometer, so it can be easy enough to get a reading and report back. Today's a good day to check, since it is in the low 30's outside (though winter overnight lows in the 20s are not at all unusual).

Why do you ask about the temperature down there? You think I might be able to get by with just the insulation?
 
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Old 01-11-07, 05:53 PM
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You should do a heatloss calculation

More or less... If it isn't much different in heat, it won't take much difference in heat. Have you done a room by room heatloss analysis? You really should. It might influence you wall composition, and material choices... it'll also basically lets you know if your existing furnace can cover it. Most furnaces are oversized and if you insulate??? If I had to bet... nah not a bettor.
 
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Old 01-11-07, 06:27 PM
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Who has made some good suggestions. You definitely want to have a complete energy audit, with blower door testing and also a room-by-room heat loss calculation. If you can add insulation where there is none for a relatively small amount of money that insulation will likely have a payback of less than a year. Weatherstripping and caulking to seal air infiltration is also cost effective. Unless you have single pane and/or aluminum framed windows (or very poor condition single pane wooden framed windows) I would probably not look at window replacement as it is normally a long term, sometimes several decades, payback. The simple and inexpensive things that tighten the building envelope have the best payback.

Now once you have made the small and easy fixes is when you want the heat loss calculation. As Who suggested, your present furnace is quite possibly oversized and a new two-stage furnace of the same size would quite likely have enough additional capacity to also heat the basement. BUT you cannot guess here, you need the heat loss calculations.

As I previously stated, I do not like zoning in residential forced air systems. There is one exception that I allow for and that is when you wish to keep a separate room (like a bedroom) at a lower temperature from the rest of the house. In this situation you may install a motorized damper in the branch duct supplying the particular room and install a thermostat in that room to control the duct damper.

In your basement you may be able to use the same idea, it mostly depends on the outcome of the heat loss calculations.


What I meant by "separate unit" in the basement area is indeed a separate furnace or auxillary heaters such as electric baseboards. Current practice for multi-level homes is to install separate furnaces for each level. I don't much care for that approach for several reasons but it does allow for easily having complete temperature control in different areas.

Yes, if you were to make major changes in your house that significantly increase its size, including a second story, I would most assuredly try to steer you towards a full hydronic system with multiple zones and radiant floors. Please understand that such would not come cheaply.
 
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Old 01-11-07, 07:31 PM
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Ummm

Furd, your arguments for forced air are all excellent. Might I temper that direction just a wee bit by saying if you were just moving into where you live now and you were going to replace your heating system which would you choose, hot water or forced air?

Factor in a lot of hot water usage, the man has a good sized family in this day and age. Even just having a healthier family would be enough for me. We have to draw the line somewhere or Who knows - maybe we'll be buying modular disposable multi fuel hot air heaters from Home Depot or wherever and all the installation money will be in the original wiring and piping. back to plumbing guys... Nope. I say do it right. You only live once - and who likes kids when they have snotty faced colds and allergies and want to be too close? LOL
 
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Old 01-12-07, 01:17 PM
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I really don't think I made any arguments for forced air as much as I made an argument for not changing from forced air.

To me, forced air does have a few attributes, the ability to filter the air within the home, the ability to (more or less) easily control humidity and the ability (if properly designed and installed) to provide cooling. Living in an area where dehumidification is rarely needed (nor humidification, either) and the desireability of central cooling is maybe ten to fifteen days per year, the main draw for me towards forced air would be the ability to filter the air. Of course these attributes "on paper" are far different from what happens in the real world.

Mechanical systems in houses rarely are considered when buying a house. Few people would walk away from a house they really liked and had the "right" price because it had a forced air heating system rather than hydronic. The same is true for steel vs. copper piping, single pane windows vs. double pane or a 125 amp electrical service vs. a 200 amp service. In my area most homes have a minimally designed forced air heating only system. Rarely are new homes built with even two-stage furnaces let alone 90+% models. Very few homes around here have hydronic heat and most of those are radiant floors and a price of well over one million dollars.

If you are asking me "If I were just moving into an existing house, that needed the forced air furnace replaced, would I seriously consider installing an entirely new hydronic system of some sort?" the answer would be, "Probably not, unless the entire house needed a major remodelling." If I were having a new house built from the ground up the answer would be absolutely yes I want hydronic and I would specify radiant floors, probably embedded in a thermal mass.

To some people money is more important than comfort. I once worked with a man that used wood in a fireplace conversion stove as the primary means of heating his home. He was constantly chopping, splitting, stacking and packing wood to say nothing about hauling ashes and lighting the fire. His home was usually too hot or too cold and his yard looked like a wood lot.

Conversely, I have known people (my mother was one) that would set the thermostat and then forget it. They open a window when they get too hot, even with heat pouring off the baseboard convector and the boiler firing like it was zero degrees. I like to strike a balance. I like to be able to adjust my thermostat for the most comfortable temperature and maximize my heating dollar at the minimal physical effort.


Now in the case of GaetanoL, who is considering major remodelling of his home and wants the ability of his young children to be able to play in the basement and on the floor (I assume) I can state that installing a hydronic radiant floor in that basement along with replacing the existing forced air heating system during the remodel may make a lot of sense from the standpoint of comfort. Installing the radiant floor in the basement would likely raise the existing level of the floor about four inches to allow for properly insulating the existing slab from the heated floor. Replacing the existing ductwork in the rest of the house during a major remodel with hydronc heat would probably be about 50% to 100% more than installing an additional separate furnace and ductwork to serve the new part of the house and replacing the furnace serving the existing ductwork. Comfortwise I have no doubt that the new hydronic system would beat the forced air system hands down, IF properly designed and installed. Of course this is assuming no central air conditioning.

It all boils down to the money issue. Would you rather have a highly efficient and comfortable heating system or hand-painted designer tiles in your bathroom? Are you willing to give up the $10,000 Viking range in the kitchen for a warm floor that your children can play on? What is comfort and health worth to you?


One caveat. The statistics show that the "average" American family moves approximately every seven to nine years. Do you consider your home to be an "investment" or a place to live? If it is primarily an investment, do you want to dilute the value of that investment by building more into the home than the market will allow you to recover when you sell?
 
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