I am in the middle of a renoation of a space (MBR and bath) that utilizes hot water baseboard heat currently.

200 sf bath will be tile. I am thinking radiant ...electric or hydro depending on ....
400 sf is hardwood.

Leaving the baseboard (or replacing with new basboard) is the first option. We are losing some wall to new doors and fireplace. So some concern there.

Would love to do radiant but it is a second floor with no easy acess. Warmboard looks nice but expensive, 4 week lead time.

The contractor is recommending radiators (European style) or Hydro-air in the AC air handler.

so 4 options.

1) stay with baseboard using higher rated units
2) go radiant using warmboard or access by removing ceiling from 1st floor
3) add radiators
4) Hydro-air in AC airhandler.

 

Your boiler will come into play here. If you do radiant the water temp needs to be lower so you will need to zone off that area with a mixing valve to get the lower temps. It would be alot of pipe work at the boiler. I would stay away from mixing heat emitters.

From what I read about the European style radiators when used with fin tub is they should be at the end of the line. I think Runtal radiators has that in the instructions.

If you go hydro air now you are removing btu's from the boiler and your boiler may and probably will short cycle more often. Wastes fuel.

I would stick with the baseboard.

What is the make and model of your boiler?

The BTU experts will give you more scientific data. I just gave the basics.

Oh and make sure you get a new heat loss calculation for your renovation. This will determain what new footage/btu of baseboard to install.

Mike NJ

 

No matter what type of radiation you choose add way more than you need but the proportion overage in each room. That allows you to work at lower water temperature. Cast iron is nice as it is about 70% radiant heat and 30% convection heat, more comfort. Radiant is the most comfortable but depending on heat loss may require axillary heat.
Personally I hat hydro-air due to less comfort and higher heat losses, the more air you move in a home the higher the heat loss.
No matter what you do you will have to change the piping at the boiler.

 

you could get creative and add a pump and mixing valve to you existing BB lines and this will get you down in temperature for use with in slab tubing.
It's not the prefect solution but it can work quite well. Use a taco zoning circulator and a thermostat in the bathroom to control the pump. There would be no call to the boiler, but during most times it will likely be moving warm enough water to do the job.
Myself, I would do the warmboard in a heartbeat. It's costly, and will delay your project but the comfort is well worth the extra IMHO. Same thing as the WC above you will need a mix valve and pump. These can be the same for both and you can utilize a manifold with telestats for each zone.
Pretty simple stuff.

 

Thanks all for the feedback.

The boiler is a 1985 vintage Weil McLain HE series 3 rated for 120K BTU/hr.

4 zones - main floor, 2nd floor, bed/bath over garage, and utility / mud room (that I leave off).

The zone for the 2nd floor has a single supply / circulator but splits into 2 loops. The current renovation involves one entire loop. So the Tee where the split occurs could be changed to an elbow to make way for a new (Non baseboard) design.

I would love radiant ... but would stay with the baseboard fin radiators as a plan B.

The HVAC sub was by again today and is still is pushing hydronic air. There is an existing AC handler in the attic, and the recommendation is to replace the AC iwith all new condenser / handler/ ductwork and add the hydronic coil to that new air handler. Thereby removing the entire 2nd floor zone (both loops). The AC may be older than the boiler and it struggles to keep up on warmer days so I am inclined to replace it proactively (even if I do not go the hydronic coil route).

With regard to radiant, he said that it may be very difficult to get the 180 degree water temp (need for running the other 3 and a half zones) to the lower 90 degrees needed to run radiant under the hardwood floor. That mixing valves can only do so much. Is this what TOheatings "creative" solution with a pump and mixing valve is intended to resolve?

he is telling me that I risk warping the hardwood due to excessive heat and that it will not be warranted by the hardwood manufacturer. I believe that if I stay with an engineered floor the hardwood will be stable. the floor manufactures documentation supports this.

He is also telling me that radiant floor heat is better suited for farther north. He said here in south jersey where I live we get warm days like we just had (70 degrees)and the radiant will stay warm for 2 days ... that i may need to run the AC to cool it off the room when the weather changes to warm that fast.

As for the baseboard design, the concern is that we will be removing about 25% of existing baseboard to accommodate new layout, and there is concern there will not be enough heat unless we use radiators. We are adding a fireplace (intended for occasional ambiance), that could offset that.

for the hydo coil design, he wants all of the ductwork / registers in the ceiling. AC / heat / supply / return. I asked if the heat would be biased to the ceiling then (inefficient) and he is telling me the hydro coil will provide uniform heat floor to ceiling (due to the use of variable speed air handler). He mentioned it operates using saturation?

he never did a heat loss calculation ... just basing off existing design.

he is recommending 2.5 ton for the AC for the 2nd floor ...

he is calling boilers old school, and that hyrdo coil is a new and better idea.

I am losing confidence that I have the right person doing the job.

 

Find someone else. He is feeding you junk and pushing what he knows.

IMHO, a nice set of panel radiators (such as Buderus, Runtal, Myson, among many options) would be very efficient and responsive. Size them to the heat loss, but be sure to do a heat loss for the rest of the house and see how your radiation-to-loss ratio looks and keep it consistent, as rbeck mentioned.

Radiant is nice, but can be logistically complex. Not hard to get right, but expensive, inefficient and poor-performing to get wrong. It's a bit easier and benefits from economy of scale in small areas (e.g., bathrooms) and larger areas (e.g., entire floor of house). You're kind of in the middle.

 

Yeah. I'm no expert, but that guy sounds a little cooky. In floor radiant heat below a wood floor is not going to give off above room temperature heat for 2 days.

As far as A/C goes, are you sure the problem is the age and size of the unit? How long have you lived in this home? My system does the same, but because I have inadequate insulation in the second floor. It also had a restricted cold air return when I moved in. Had that rectified and it does perform better.

Boilers may be old school, but they are the best.

 

so in fairness to the HVAC sub, he did propose the panel radiators too. I think we will go that route. Thanks for that feedback.

I believe that the AC problems are related to multiple problems. Supplies are undersized and there is just one return. It is very noisy when it is running. I had it serviced at the start of last season and the HVAC guy added refrigerant and measured deltas, etc. it ran better when he was done. He said that the compressor and air handler were not matched so the compressor was probably updated more recently and they did something funky with the a reducer which would not be code today.

The logic of replacing hte second floor AC now is that we already redoing half of the duct work anyway … so going with a new unit all around to make it overall quieter, more efficient, and able to keep up seems to make sense.

 

Food for thought,
a) you can set up a Taco iSeries valve to use outdoor reset and mix down your 180 degree water to any temp between 70 and 180. It will be weather responsive so that rooms tend not to overshoot. It will be a very efficient way to heat you room.
b) you can do steel panel rads, but the water would also have to be mixed down as to not drop the overall system water temp,
c) If you are going to replace the A/C system, you might consider a heat pump. The newer air to air heat pumps are fairly good at getting heat from cooler outdoor temps. Your in Southern NJ ? so the outdoor design is not that low anyways... Heck you guys barely get snow (hahahahaha).

My choice would be option 1 [I think he means option 'a' ? NJT edit]

 

Air source heat pumps are not that great for nj. You will be on aux heat quite a bit in the winter.

 

Yeah on the Runtal site its says put at end of loop if used with tube fin BB. I think he said he is on one loop with this renovation.


NO SNOW!!!!!

We could not get out for two days. But I was riding last week.

Pictures by lawrosa - Photobucket


Mike NJ

 

Knew that would hit a nerve :-)
You guys have been hit good this winter.
I did a few trips to Triangle tube years ago and rarely was there much snow. Know we did get nailed in a billiard on the way back from Jersey once.
I quite miss my trips down there, need to go again soon.

 

There are new HP's out there that work very well in colder climates...
If it works up here, it will work in Jersey. It does tail off in efficiency somewhat, but it's viable.