Heating: Hydronic Radiant Heat Question (flooring, how much, windows, hot water baseboard)
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I recently bought a 15 year old home with hydronic radiant heat in the ceramic tile floor. I have a gas fired boiler and I'm happy with the way it heats the house. The system seems to cost less to run than my old forced air system at my other house. But - the climate here is dry and a little warmer than where I moved from so that might be the difference.
This is new to me and I'm puzzled about a few things.
I have four zones. Once the house is heated I leave the thermostats alone and use ceiling fans or open windows if it gets too hot. That doesn't seem efficient but the system is slow to respond if I mess with the settings. Is that how these systems work? I'm assuming that the slab probably heats up and it would take a while to cool down and then would take a while to heat back up.
Is this connected to my water supply system or is it a closed system? Where does the water come from? Should I be hearing running water?
Once the house is heated I leave the thermostats alone and use ceiling fans or open windows if it gets too hot. That doesn't seem efficient but the system is slow to respond if I mess with the settings. Is that how these systems work? I'm assuming that the slab probably heats up and it would take a while to cool down and then would take a while to heat back up
They have thermostats designed for radiant heating. I'm not reccomending these but just pointing them out:
Is this connected to my water supply system or is it a closed system?
Yes and yes. On your boiler is going to be a supply for the water, there will be a pressure reducing valve because the water in the system is much lower than the water from the street. Once the water enters the system it never leaves unless there is a leak.
That water in the system is circulated with pumps in a loop. You're going to have one line going out to the zone and one that returns the cooler water to the boiler. Sometimes they can make noise but usually they are dead silent, if you are hearing a gurgling sound you probably have air in the lines. Most systems are going to have automatic air bleeders.
Isn't radiant heat more energy efficient? I've read some about this type of system and think they would be. It's been years but I recall my elementary school having this type of heat system in the classrooms. The floors were always so warm and the rooms very comfortable.
All things being equal hot water baseboard or radiant floor heating is going to be the same.
The efficiency of any system is based on the BTU's in the fuel and how much gets used to heat the home. For example electric is 100% efficient because there is no heat loss, natural gas might be 85% efficient because it loses heat to the outside. You need to vent the gases which also takes some heat with it.
The efficiency of the system inside the house can vary, it's not really an efficiency problem but a heat loss problem. For example if you have a pipe going through some space you don't want to heat like a wall where most of that heat is going outside.
Quote:
The floors were always so warm and the rooms very comfortable.
As far as the comfort it's the best heat you can have assuming it's setup properly.
Thanks, I didn't know a lot of that. I'd imagine it's less expensive to install something like that while the house is being built or remodeled and not just an afterthought. Seems it would be quite costly to tear up a perfectly good floor to install. Right?
On those cold mornings, it would definitely be nice to step onto a warm tile floor.
Thanks. This is my first heating season and I'm liking it a lot but just wondered how it worked. The floors are warm but that heats up the whole house very nicely. I just don't recognize the machinery compared to my old gas forced air system.
Thanks, I didn't know a lot of that. I'd imagine it's less expensive to install something like that while the house is being built or remodeled and not just an afterthought. Seems it would be quite costly to tear up a perfectly good floor to install. Right?
On those cold mornings, it would definitely be nice to step onto a warm tile floor.
Depends, it's expensive.
New house with no basement or in the basement is usually pex going into slab of concrete. They pour the concrete over the pex:
They have flooring with channels if it's not going into a slab:
There is all kinds of systems though, minimally they have thin mats that use electric. Probably not a great idea for whole house because of the cost for the electric but something to consider for the bathroom. The only thing that can be retrofitted without redoing the whole floor is a system like this however the opinions I've heard are mixed and you's access to the underneath of the floor. If you have really thick flooring it might nor work that well.
I have four zones. Once the house is heated I leave the thermostats alone and use ceiling fans or open windows if it gets too hot. That doesn't seem efficient but the system is slow to respond if I mess with the settings. Is that how these systems work? I'm assuming that the slab probably heats up and it would take a while to cool down and then would take a while to heat back up.
Is this connected to my water supply system or is it a closed system? Where does the water come from? Should I be hearing running water?
It sounds like you might have your thermostat set too high if the house is getting too hot.
Your boiler has a closed loop. However it is connected to your fresh water supply by a valve that will add water if the pressure gets lower than the system is designed for. Ours is designed for 20 psi.
Here is how infloor radiant heating works.
The thermostat calls for heat. Your boiler checks to see the temp of the closed loop. If it is below a preset amount (ours is about 155 F) it turns on until it's limit is reached (our boiler is set to 180 F). When the call for heat is made the thermostat turns on a pump, a zone valve is opened to the zone that is calling for heat and the water flows. There is a mixer that mixes the hot water from the boiler with cold return water from the zones and cold water from the closed loop.
We have heated tile floors but set our mixer to about 120 F so we get a quicker response than some systems. Heated tile floors could easily be set to 107 F so this provides slower response. Our system is designed to work up to 140 F but I think that is too high of a temp to send to ceramic floors. It would be a good temp to use with wool carpeting or something that is highly insulating.
The thermal mass of your floors is huge so it does take some time to heat up and cool down. We have our house set at 70 for the master bedroom and basically never change it. The upstairs is set at 67 and basically we never change that. The main living area is set at 73 on cloudy days and 70 at night. If the day is going to be sunny I don't change it in the morning (leave it at 70) as the passive solar we get will heat the house up by at least 3 degrees, sometimes more.
It would be worth your time to spend some time trying to trace out the water flow on your system so you can see how it work, what the gauges are reading during normal operation, and understand the components. It is really easy to change them out. That way you save money on a plumber if your handy or know when your dealing with a shyster if your not. Buying replacement parts on-line and changing them out yourself will save you a bundle.
Costco.com currently sells electric radiant heaters, but as others have said hydronic is more efficient for heating a whole house. Personally, I'm jealous of those with radiant heat...I'm a poor soul with forced air. Radiant heat due to warming a large thermal mass is better at retaining heat whereas warm air quickly moves to areas of colder air.
When I remodel our two bathrooms, I will install a radiant system. I'm not sure if I'll tap into the water supply line for a hydronic system or go with an electric system. I wonder if hydronic would work to my favor since I have a tankless water heater.
Our house has in floor HRH and I prefer it greatly over forced air. The air doesn't get as dry and there is no fan noise.
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