floor heat disappointments?

[tdkkart]

anybody have trouble with the floor heat maintaining an even temperature ? ours at work swings 12 degrees if it 68 in the morning it will be 80 by quiting time. Any ideas where to start?

Where's the thermostat, right by the man door that everyone goes in and out of all day?? If something is tripping the thermostat every 15 minutes telling the boiler to dump a load of hot water in the floor, eventually the floor temp will creep up. Would the T-stat happen to be on an exterior wall??

I had a similar situation when I first started with my radiant floor. The previous owner had done the floor in a portion of the building before I bought it. All seemed well and good except that every once in awhile when I got to the shop the heat was running like crazy, ambient temp was way up yet the T-stat looked normal. It acted like the thermostat or the pump relay was stuck.
For some reason I realized one day that the T-stat was on an exterior wall, and the system only acted up on windy days. I pulled the T-stat off the wall to find the wire coming the through a 1/2" hole in the plywood wall with a steady breeze blowing right on the sensing coil in the T-stat.
Moved the thermostat, never had an issue again.

 

[nate379]

How much wood is that? I'm used to a standard trailer load which is about 10 cords.

And I can heat my 30 x 40 shop and home on about a semi load and a half every winter.

 

[just1more]

I built my garage about 6 years ago. It's aprox 48 x 32 with 10 foot ceilings. At first I considered using in floor heat. I keep my shop about 48-50 degrees all the time. but like some of you have said, the "problem" for me was , if I want to work out there without planning ahead, it would take a long time to bring it up to 60.

I ended up using a natural gas high efficiency forced air furnace. I have heat ducts in the ceilings around the perimeter of the outside walls. I can heat the shop up to 60-65 in less than 20 minutes. I keep my plow tuck in there so the 16x 8 door is opened at least twice a day. Recovery from the cold air blast is pretty much instantanious.


The other thing, living in the midwest there can be fall/spring days that I have the overhead door open one day. The next day the heat is on. We pay a monthly average, all year round, on the gas bill. For the past two years the monthly average has been less than $85. That also includes the heat for our 2400 sq.ft. farm house.

I can say, I have never been sorry for my choice of heat.

 

[theoldwizard1]

I think it was propane.

IMHO, anyone who heats with propane should have their head examined !

About 8 years ago, my in-laws built a new house in NW NC (foothills of the Smokies). They had no access to natural gas so the builder recommended a heat pump with forced air. They have propane gas logs in the main level and basement "fireplaces" as a back up (I don't think they have ever used them).

A few years ago, someone built next door to them. Similar house, approximately the same square footage. He had propane fired forced air installed. A lot cheaper. Until the first winter. His propane/electric bill is 3 to 4 times as much for the winter months as compared to my in-laws.

If you live in a colder climate, check into Geothermal Heat Pump. Expensive, but it will pay for it self !

 

[Jackfre]

IMHO, anyone who heats with propane should have their head examined !

About 8 years ago, my in-laws built a new house in NW NC (foothills of the Smokies). They had no access to natural gas so the builder recommended a heat pump with forced air. They have propane gas logs in the main level and basement "fireplaces" as a back up (I don't think they have ever used them).

A few years ago, someone built next door to them. Similar house, approximately the same square footage. He had propane fired forced air installed. A lot cheaper. Until the first winter. His propane/electric bill is 3 to 4 times as much for the winter months as compared to my in-laws.

If you live in a colder climate, check into Geothermal Heat Pump. Expensive, but it will pay for it self !

Propane is a very viable fuel...if you use the right equipment. A standard single stage furnace is an invitation to get killed. Heating equipment is designed and selected based upon degree days. If you figure the heat loss, it is a number which on the coldest day of the year, the properly sized unit will run constantly, but keep the place comfortable. The problem is that are rarely at design condition, so your equipment, which is generally oversized by factors, short cycles and runs very inefficiently. Have you ever heard someone say they hate warm air? it is because you get a big blast of hot air followed by shut down and draft/cool down and another blast. The way to make propane efficient is to go with modulating equipment, both for the burner and blower. What is important is how low the unit will fire, not how high. Yes, there are times that statement can get me in trouble, but rarely.

I bought a house a few years ago and it had absolutely the worst heating system I have ever seen, and I visit heating jobs all day long, pulling thorns out of contractors paws. It was propane and you could watch the gas level drop on the tank. it was like driving my old beloved 454 3/4 ton truck from a long time ago. I eliminated that system and put in two mini-split systems and a couple Rinnai Energysavers. The ultimate in zone control.

You are correct that Geothermal HP's will pay off, if you stay there for a long time. In todays world, you can use the mini-split systems and very nearly get the same performance without the water and the very high front end costs. they are the ideal addition to any existing system. Don't change your system. Add!

 

[swamp_donkey]

How much wood is that? I'm used to a standard trailer load which is about 10 cords.

He usually brings 7-8 loggers cord. One loggers cord usually will render 3-5 face cord.

 

[nate379]

Floor heat...
I like the fact that the floor is warm. It's VERY nice in the bathroom and in the garage. BUT I don't like the slow response time. I think I'm like most folks that when I'm cold I want the house and I turn the heat up, I expect it to warm up soon, not in a several hours.

When I bought this house I was under the impression that radiant floor heat was the best way to heat a building. There are many webpages that claim that it's very energy efficient.

Well there are things that I didn't think about that I think forced air would be better.

#1. Air circulation and filtration.
#2. Quick response.
#3. Cheaper to operate. Don't need to heat the house at 68* all day for the 8-10 hrs that a person might be home.

When it would get cold outside (well below zero) it seemed like the boiler was almost ALWAYS running to keep the house warm. With the wood stove I burn on a very low setting and I have no trouble keeping the house at 70-75* I could make it 90* in here if I wanted to.
I have only burned about 2.25 cords of wood this year and have heated the house with wood the whole time other than 2 weeks that I was out of state.

 

[theoldwizard1]

Propane is a very viable fuel...if you use the right equipment. ... The way to make propane efficient is to go with modulating equipment, both for the burner and blower.

I'm certain your statements are accurate, because they also apply to natural gas fired furnaces ! That still does not make it a "cost effective" solution.

LP is made from oil and we all know about the price of oil.

You are correct that Geothermal HP's will pay off, if you stay there for a long time.

The pay off is faster if you live in hot (think FL, TX, AZ) or cold (MN, MI, ME) climates.

In todays world, you can use the mini-split systems and very nearly get the same performance without the water and the very high front end costs. they are the ideal addition to any existing system. Don't change your system. Add!

I was thinking primarily new construction.

 

[z28toz06]

Floor heat...
I like the fact that the floor is warm. It's VERY nice in the bathroom and in the garage. BUT I don't like the slow response time. I think I'm like most folks that when I'm cold I want the house and I turn the heat up, I expect it to warm up soon, not in a several hours.

When I bought this house I was under the impression that radiant floor heat was the best way to heat a building. There are many webpages that claim that it's very energy efficient.

Well there are things that I didn't think about that I think forced air would be better.

#1. Air circulation and filtration.
#2. Quick response.
#3. Cheaper to operate. Don't need to heat the house at 68* all day for the 8-10 hrs that a person might be home.

When it would get cold outside (well below zero) it seemed like the boiler was almost ALWAYS running to keep the house warm. With the wood stove I burn on a very low setting and I have no trouble keeping the house at 70-75* I could make it 90* in here if I wanted to.
I have only burned about 2.25 cords of wood this year and have heated the house with wood the whole time other than 2 weeks that I was out of state.

**************
Air circulation is one of the primary reasons I don't want a scorched (forced) air system. It spreads dust (and disease, think legionaires disease) allergies etc.through the house and causes the warm air to rise. In a forced air or baseboard type system it's not unusual to find 10 and sometimes 20 degrees difference in a room, from the floor to the ceiling. A proper radiant hydronic system will find temps from the floor to the ceiling just a few degrees difference.

The whole "cheaper to heat" theory is subjective also. With forced air, you come home and crank up the heat, attempting to warm the air, but the furniture (or cars etc, if in a garage) has dropped to whatever temp the room has dropped to. Of course to the touch it always feels colder due to the way we lose heat through our skin. Additionally the air blowing around the room will actually cause you to feel colder due to the convective heat loss from the body with that air blowing on it. It is actually disadvantageous to turn ceiling fans on in the winter in hydronic heated rooms, as it will cause the currents or "warm air rising" scenario.

As far as wood is cheaper theory, I say hogwash. Cutting 7 or 8 cords of wood in a day, while possible, is a large undertaking. I used to burn 9 to 10 cords of wood a year and I would usually accomplish this by having a pile of buds over and would invariably end up buying pizza and beer to feed and water them.

Then there's the splitting, stacking, moving it 3 times from the big shed, to the house, to the stove ordeal. Sure it's less money out of pocket, but my idea of money well spent is pay the propane guy and just be able to flip a Tstat, when I need heat. If you are worth your salt, you can figure your labor worth 30 bucks an hour, and that's without taking in to account the bumps, bruises and cuts, saw chains, gas, oil etc. And let's not forget how sore you and your buddies are the next day or two after cutting, splitting, stacking, and the necessary clean up following all that!

I can make more money at work in a day than it would cost me to pay for the propane gas needed for a month, and I don't get a single splinter. Plus the off chance of getting busted up bad enough to miss a few days (or more) work.

I did it when I was younger, because it was my only option, but I don't miss the pain and the mess and cleaning the dust in the house and having to paint every couple years from it all.

 

[nate379]

I bought 3 cords of wood for $600 and I have about .75 cords left. Been heating since October.
I can get it cheaper, around $125 a cord if I buy green wood. Just this year I bought wood in early fall so it was too late for that.

That is about 3 months worth of natural gas.

When the power was out for several days and it was -10* outside, I was reading by lantern light in a 70* house

I don't get sore doing a few cords of wood but I'm only 28. Being outside and getting some excersize isn't a bad thing either.
I do know what you are saying though, my folks have been heating with wood for over 30 years and this summer my Dad is putting in a rice coal stove to replace the wood stove (works kind of like a wood pellet stove)

I completely disagree with the "scorched" air deal as well. Work outside all day and tell me that standing over the heat register, or in my case the warm wood stove, isn't comfy?

And if you have a filter on your force air system, you shouldn't be blowing dust all over the place. It also helps to spread the humidity around the house... bedrooms (people breathing) and bathrooms can make quite a bit of humidity.

 

[sneezer41]

Nate,

let's face it, there is something wrong with your radiant heat system, nuff said.

I love a woodstove too, I'd run one too if had nothing better to do with my time. I could heat for free no doubt. I would do it just for fun. Turns out I do have other things to do.

Hot air heat is utilitarian, but not comfortable.

 

[nate379]

I could sit here and argue all day long, but whatever I say it's going to be wrong apparently, so what's the point?

There is nothing wrong with my radiant system, it works like it's supposed to. I just don't like the slow reaction time and you can't tell me that no air circulation in a home is a good thing!

 

[walrus]

you can't tell me that no air circulation in a home is a good thing!

What kind of circulation? If you feel that you need it, get an air to air heat exchanger. I know your house is tight but I doubt its that tight that no air is moving. Turn your bath fan where is the makeup air coming from?

 

[theoldwizard1]

For others following this thread, there are 2 negative things about radiant heat.

• It is difficult to add moisture if your humidity is too low
• It is difficult to lower the ambient temperature and humidity if one or the other is too high

 

[nate379]

Whole house circulation. Would help to move "stale" air around, example from a bedroom to the rest of the house.
Yes house isn't air tight of course. Bath fans pull air from attic. (have an inlet vent in the hall that is more or less a stud cavity with part of the top plate open)

What kind of circulation? If you feel that you need it, get an air to air heat exchanger. I know your house is tight but I doubt its that tight that no air is moving. Turn your bath fan where is the makeup air coming from?

Radiant isn't "comfortable" because it's not fast to adjust. I might be fine at 65* one day while a few days later I am cold so I want it to be 70* in the house. Ok.. house will warm up... several HOURS later... by then I might not even be home anymore.

In my garage I am forced to keep it heated much warmer than I would normally just for when I want to work in it. If I left it at 45* as I would do with a normal "hot dog" heater, and set it to 65*... It would take a good 6-7 hours to warm up to that point.

Like I said in an earlier post, the best setup would be a system that incorporated radiant and forced air.


And I keep reading about radiant warming up the objects in the house vs forced air "burning" the air.

Uh.. if I take a block of wood and set it outside, -10*. Bring it in the house, 70*. That block of wood doesn't give a rats *** if the heat comes from the slab or from the air... either way it will warm up to 70*

 

[walrus]

.

Like I said in an earlier post, the best setup would be a system that incorporated radiant and forced air.*

You have that with a wood stove. I think if you had family living there so the house was occupied more of the time it wouldn't be as big a problem, you're gone alot so you keep the Tstat down.

I heat my entire house with 1 woodstove. Its not perfect thats for sure and I have oil backup but I'd rather feed Maine families than I would Saudi familes.

In my shop my solar radiant has worked great, kept it above freezing all winter, crank the woodstove when I need it warmer.

 

[theoldwizard1]

Like I said in an earlier post, the best setup would be a system that incorporated radiant and forced air.

The reason why this is true is because of our perception of hot and cold.

Let say you have a shop that you turn the temp down to 40F overnight. You come in in the morning and flip the thermostat up to 65F. Yes, forced air will get the volume of air in you shop up to that temperature faster than radiant floor heat. But you won't be comfortable. Why ? Because the slab is still only about 45-50F. And getting that slab up to temp will take a long time.

If you are going to have a radiant floor system that will have to deal with wide temperature swings, you will probably need a bigger boiler and in-floor tubing placed a lot closer together. A good radiant engineer would know this and design these in.

"If your feet are warm, you will be warm." From my uncle who installed a radiant floor system in his basement about 50 years ago so his wife could run her business down there in comfort. (He was a plumber and he used copper pipe.)

 

[just1more]

Like I was saying earlier, I have a natural gas, high efficiency forced air furnace, One thing I find with my shop is the "sweet spot" for the low temp. If I keep the low around 50, I can bring my shop up to a bit over 60 in 15 - 20 minutes and the furnace does very little cycling.

I used 3" thick "blueboard" foam insulation on the inside of the foundation before pooring the floor. This helps a lot in keeping my floor from feeling cold.

Much below 50 and recovery takes longer, plus furnace cycles more trying to bring everything up to temp.

One other positive thing about the forced air furnace, in a couple of years I'm hoping to have the AC unit hooked up!

 

[nate379]

I don't have a family, but there is almost always someone here day and night. I keep the T Stat for the boiler down cause I hated being bent over when I get the gas bill each month

You have that with a wood stove. I think if you had family living there so the house was occupied more of the time it wouldn't be as big a problem, you're gone alot so you keep the Tstat down.