sliders and heaters

[Cooler]

The entire rear of my home has windows that go from the  baseboard heater to door height.  They are original to the home,  single pane and not energy efficient.

The windows in the living room overlook my deck (a nice deck with a view that spans probably 60 or 75 miles).

I would like to replace those windows with a 12 foot slider.  I guess it would be 4 doors or maybe three doors.  It would allow the living room and the deck to become one in temperate weather.

But I would loose 12 feet of hot water baseboard heat.  

I recently had my furnace serviced and I asked the mechanic what the work-around would be.  He said that since I would have about 35 feet of baseboard in the room after I removed the 12 feet that it would be enough to keep the room warm.  I have my doubts.

It is the ground floor of a ranch house.  The house is heated with hot water baseboard heaters.  The furnace is an oil burner.

There is easy access to add ducts directly into the floor.

The house has what was considered an "engineered" system with each run of radiator being metered by a valve ranging from "1" to "4".  No one knows what those valve numbers mean anymore.  It is possible that I can increase the heat in the room by removing the valve and putting in a more free flowing one, but all the contractors say, "It would be easier to put in a second zone."

What are my options?

[blackhat]

Post a picture of the valve. There are several possibilities depending on a couple factors

[Cooler]

Post a picture of the valve. There are several possibilities depending on a couple factors

I will take a picture.  I think I misstated the description, it probably would be called a "restrictor" rather than a "valve", it is a cast junction with an aperture inside that controls the flow of water.

As I recall the restrictors ranges from 1 to 4.  This is 1953 technology and no one seems to have a clue about how it works.  It was, apparently, fairly sophisticated at the time.

Radiant heating is a possibility.  Is it an efficient way to heat?  I have oak hardwood floors over a subfloor.

Is there a hot water heater blower than can be hooked up to blow through floor mounted vents?  That could be workable.  In that case I could have a thermostat for the blower motor to control the temperature in the room

[blackhat]

Yes, there are many styles of fan forced cabinet heaters.  Under floor ducted, flush mounting, kick space under cabinet styles.  You need to pay attention when adding them to a baseboard or other radiator circuit.  They should be the last emitter on the circuit and sized for water temps about 10 degrees cooler than you are supplying to the rads.  Going the other way can result in the rads getting cooler water than anticipated and losing output.

[TDKPE]

I know relatively little about residential hydronic heating, other than what an engineer homeowner type would know, but I do loads of hydraulic system design.  And heat exchangers for hydraulics and other systems have performance curves relating heat transfer to flow rate, with other variables fixed (delta-T and air flow, for instance).  So, just tossing it out there, but would it be possible to 'upgrade' the baseboard units to units with higher heat transfer rates, all other things being equal (specifically water flow rate and inlet temperature), to make up for the loss of linear footage?

A question for the HVAC guys, of course.

[MikeBob]

I am not a heating expert. Could you redo that heater line to one of the under the sub floor heating heating kits. It mounts in the basement to the sub floor above, in between the floor joist.

[MikeBob]

This is the style I was referring to.
https://www.youtube.com/watch?v=gvVZhhlrrts

[daddo]

We don't have that type floor heating here and I ask for curiosity.

Would it be more effective the have some type of gel to place between that floor plate and the flooring, and the space between the tubing to the plate to aid in the transfer of heat at those connections? I guess the heat is still trapped in that space and it wouldn't matter..?

My son has an older 3 story house in Pittsburgh with the old radiators and a new boiler. I was impressed with the heating in the home.

[blackhat]

That style system can be effective but a couple principles need to be kept in mind, the raw physics of heat flow.  You need more insulation value on the side you want the heat to be stopped and less on the side you want it to flow to. You also need to keep in mind the temp differences.  Having R50 below and R40 above will still transfer heat but the space around the tube will quickly reach fluid temp and it will reduce the rate of heat transfer to near zero.

I don't know what the OP has but the staple up system is one possibility.  Another is to create a natural convection heat chamber below the windows or doors.  Essentially, you enclose a heat emitter ( fin tube element from baseboard works well and is cheap ) in an insulated box and cut register in the top and bottom.  The air in the chamber is heated and natural convection causes it to rise out the top registers and cooler air comes in to replace it and continue the cycle.  A bathroom fan can be used to increase the output of the chamber and is a good way to go if you have an area that can benefit from extra heat and airflow, like eliminating frost on large glass surfaces.  Same idea as placing forced air registers below windows.