| Click to Post a New Message!
Page [ 1 ] |
|
|
|
Retrofit radiant floor heating
We are having a LOT of snow for this area, and we've had a half dozen power outages of 6-8 hours so far this year. It gets mighty cold sometimes and the two fireplaces aren't cutting it. Our 13kw genset will run everything we need except the heatpump, and it would cost maybe $8-10k to install one large enough to power that.
I was thinking of retrofitting a radiant floor system on the main floor of our house, heated by the propane hot water heater. A number of companies advertise these (radiantec comes to mind). Most of our main floor is wood so we don't have to deal with the insulating characteristics of carpet, and the basement ceiling is fully accessible. They claim you don't need a heat exchanger but I'd install one anyway to insure the safety of our potable water.
I'm interested in knowing if anyone has used one of these sytems and, if so, what your experiences were.
|
|
 Add Photo
Bookmarks: |
|
| |
|
Retrofit radiant floor heating
Thanks, JParker, not an overkill answer at all. The heatpump is a 6 ton three zone geothermal unit with a 14.4/19.2 KW strip heater as aux third stage heat. There are three separate disconnects on the unit and one of them serves the fan only (I think).
I hadn't thought about a hot water coil - that's an idea. The difficulty as I see it is that the entire heatpump is in the basement wedged between the basement floor and ceiling. The supply duct goes through a chase to the attic and branches off, and it's all framed in so it would be hard to get to. The return air comes out the basement ceiling and passes through three filters (EAC, media, and UV) so there isn't much room for a coil there either. Still, it's an intriguing idea. I'm having a guy out to purge our geothermal loop and I'll ask him what he thinks.
Companies like Radiantec push using the hot water heater as the hot water source. Our hot water heater is a HUGE 90-100 gallon Bradford-white unit that has a very fast recovery rate so it might work. If not we could always plumb in a small boiler (which would double the expense of the system). They sell these systems as retrofit using the sheet metal reflectors under the subfloor. I'm not sure how well these work though. I suspect I could do this for a couple of thousand bucks, which would be quite economical compared to a new genset.
|
|
Add Photo
Bookmarks: |
|
| |
|
Retrofit radiant floor heating
It's a vertical WaterFurnace unit.
Actually, I hate it. Not only has it been unreliable, but it uses double the KW power than WaterFurnaces projections said it would. I log the consumption of each circuit feeding the unit and I know exactly what it uses, and WaterFurnace was way, way off.
Yes, we are using less than others in the area with similar sized homes but due to their erroneous projections the payback will never be realized. And the system is installed correctly - we've had three other contractors out looking at it and they have found no problems. Plus, we've had blower door tests (the house is tight with a 0.28 ACH) and duct pressurization and sealing tests.
|
|
Add Photo
Bookmarks: |
|
| |
|
Retrofit radiant floor heating
We have a horizontal loop.
It's very generous of you to offer advice. I'm sort of at my wits end on this, so I could use an informed third party opinion. I'll put together some information and send it to you. Your profile doesn't list your email address but if you send a blank email to me (ken at qsolv dot com) I'll have it. I really, really appreciate it.
I sent a letter to the president of WaterFurnace, explained our situation, sent them copies of their energy consumption estimate vs. measured consumption numbers, and offered to pay half the expenses if they'd send a tech out to evaluate the system and they refused. Our dealer dropped them due to excessive warranty claims and insufficient warranty reimbursement. I think they're a crappy company.
|
|
Add Photo
Bookmarks: |
|
| |
|
Retrofit radiant floor heating
Thanks, John, your email was trapped by my spam filter but I got it and whitelisted your name. If you get a bounce notice just ignore it.
Thanks,
Ken
|
|
Add Photo
Bookmarks: |
|
| |
|
Retrofit radiant floor heating
Thanks, guys, for all the good suggestions.
Blizzard, I hadn't considered direct-vent propane heaters. Are those the wall-mount heaters? One problem is that for such a big house we have an incredible lack of available exterior wall space. We have a lot of floor-to-ceiling windows in all living areas. Might be able to put them in one or two bedrooms or the basement, though, and circulate some air. I know what you mean about in-floor heat being a project. I'm not sure it would be a whole lot worse than trying to get propane to the bedrooms though 
Billy, when we built we plumbed and stubbed out gas to both fireplaces. Do gas logs put out that much more heat? When we stoke the fires with wood and turn on the circulation fans (generator powered) it feels like we get a lot of heat out of them, just not quite enough to keep the whole above 60 degrees. Of course in-floor heat in the main floor won't heat the bedrooms either.
Peters, a pellet stove sounds good but again a lack of wall space would limit where we could locate it. The hearths are raised and are too short to hold a stove. Our neighbor has one and doesn't like it and I sort of dismissed the idea due to that. Maybe he just doesn't like the fact that it doesn't work when power is out. It seems it would be convenient auxiliary heat though. A hot water coil in the supply air would probably be cheaper, assuming we could run it off the water heater.
AC, if we do the radiant floor it will only be done in the living spaces on the main floor. Maybe two zones at most. You have reaffirmed my desire for a heat exchanger - we're on a well too with no chemical treatment. Our main living space is vaulted and we have problems with stratification anyway, so in-floor makes sense from that perspective.
|
|
Add Photo
Bookmarks: |
|
| |
|
Retrofit radiant floor heating
Gotcha, Billy. I didn't think about "vent-free" when I read it. There are no combustion by-products to worry about?
Beautiful fireplace by the way - love the stonework and the curved hearth. I won't show it to my wife
|
|
Add Photo
Bookmarks: |
|
| |
|
Retrofit radiant floor heating
Blizzard, thanks for the links and info. I need to do more research on the propane heaters or log sets, it sounds promising.
We were actually thinking of retrofitting radiant floor heat on our main floor anyway, and using it as emergency heat was an afterthought. Our main living area is vaulted with a 24 foot ceiling and it's hard to keep it comfortable, so in-floor heating seemed like just the ticket. Then the snow fell and it clicked that it could provide some heat when the power is out as well. If we went that route it would provide heat all winter, not just when the power goes out so cycling of the wood floor shouldn't be an issue.
The best setup might be a combination of in-floor and auxiliary heaters (heatpump most of the time and gas heat when power is out). Not all of our outages are short - it was out for a week last year.
|
|
Add Photo
Bookmarks: |
|
| |
|
Retrofit radiant floor heating
Eric, I've heard conflicting stories of problems with underfloor radiant heat on wood floors. It's confusing and hard to know if there's a legitimate problem or not. I figure that heating the floor to some moderate temperature, like 60-65 degrees, and using the heatpump to make up the difference may minimize any problems.
We also have a ceiling fan on a 10-foot downrod in our vaulted area. The fan helps a lot but there's still a 2-3 degree temperature gradiant floor-to-ceiling. Our heatpump also has a desuperheater to provide hot water but I turn that pump off in the winter since heatpumps heating performance is already marginal. We use propane for the cooktop, water heater, dryer, generator, and have it stubbed out to our fireplaces and outdoor future hottub.
|
|
Add Photo
Bookmarks: |
|
| |
|
Retrofit radiant floor heating
We have 7-8 sf of return air vents at the peak of our vault so that pulls hot air from the vault ceiling and recirculates it. I know that works 'cause I have to vacuum the registers all the time We run with continuous fan to even out the temps and better filter the air (wifes allergies).
How do you heat the tank without desuperheat?
|
|
Add Photo
Bookmarks: |
|
| |
|
Page [ 1 ] | Thread 72982 Filter by Poster:
1 | 2 | 3 | 5 | 10 | 1 | 4 |
|
()
Picture of the Day
dododo
Unanswered Questions
Active Subjects
Hot Topics
Featured Suppliers
|
Gas Generator Weather Protecti
01-03-2004, 20:25 
Digg It 
Del.icio.us