New system for shelled house

Peter Serwe

Here's the situation:

After reading through a bunch of posts, I realize
that this place is mostly populated by professionals.

2 of them are located within 80 miles of me.

I'm the H.O. - I know very little about exactly
how this stuff works. I have no question in my
mind that I need a contractor.

My idea is, I want a radiator based system, even
though I built my house with the initial consideration
of doing a joisted radiant floor application.

I'm not sure if I want steam or hot water.

I know I want an oil-fired boiler. I have the
bare uninstalled fuel tank in the basement
already, I also have a doubleflue chimney set up
in roughly in the area where I had planned to put
the boiler. This location is semi-central to the
house, with both entries to the chimney in the
basement to vent a wood stove and the boiler.

So, that all leaves me with the question of
hot water or steam. My considerations are
efficiency, cost, and simplicity. I do not
plan on installing any of it myself, for simple
reasons:

A. I definitely don't know what I'm doing.

B. I've heard that some some boiler manufacturers
do not warranty boilers not professionally
installed.

What I want to figure out is what the ideal approach
would be, and what the downsides are.

I also have some heat loss information based on a
freely designed radiant system that after carefull
inspection looked to be leave out all kinds of
important considerations.

Flames, experience, help, lambasting, is all welcome,
I learn from everything ;)

Thanks MUCH

Peter Serwe

A side note

I'd like to mention that there's I'm not looking
to install this until next spring - I realize this
is the busy time of year for all you guys.

I'm trying to get my plan of action mapped out
prior to getting contractors to bid on it.

If I do end up having to use a more local contractor,
I want to have a plan to give him.

Dale

If you have complete house plans

and a heat loss just about any contractor that does boilers on a regular basis should be able to design and install a baseboard HW system for you, there are people on this site that could do a nice job on a new steam system but the first cost add on and fuel use with a new modulating HW boiler would save you alot of cash. If all you want is a really complete professional design by someone who isn't looking to sell you anything else look for Tom Meyer in the find a contractor section, and the radiant zone for at least the baths would be comfort well spent.

Mike T., Swampeast MO

A two-pipe hot water system with cast iron radiators, black iron piping and thermostatic radiator valves would be the most expensive initially but will offer extreme life and exceptional comfort. Finding a supply of old radiators suitably sized in a short time may be difficult. New ones are available, but they are quite expensive. PEX piping (or possibly copper) could be used to reduce installation costs.

A two-pipe hot water system with steel panel radiators, copper or PEX piping and TRVs will provide a system comparable in comfort to the above and likely at significantly lower cost.

Constant circulation and reset are DEFINITE benefits to the above. Since your home was designed with joist-bay radiant heat in mind give HIGH consideration to installing radiant heat in the bathrooms (at a minimum). Such should be quite cost effective in the above systems and will give you radiant floors where most people appreciate them greatly.

Single-pipe hot water systems can be designed to work with either iron or steel radiators. Single-pipe systems must be VERY carefully designed and don't take well to later modifications. While they can be designed to utilize thermostatic radiator valves and constant circulation, such must be done with great care.

If budget and space allow, sizing the radiation to operate at lower than normal temperature will have a corresponding increase in comfort and, likely, efficiency.

One-pipe steam is more difficult to control and generally less efficient than water. While it used to be less expensive than even a one-pipe water system I do not know if this is still the case. Two-pipe steam systems operating at very low pressure can, I believe, approach the efficiency of simple water systems. Finding someone to design, install and maintain a residential steam system might be very difficult.

Steamhead

On the other hand

a steam system won't freeze like a hot-water system can.

When properly installed and maintained, either system will give you efficient comfort.

To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"

Mike T., Swampeast MO

Steamhead is right of course

While it took 70+ years, a freeze-up is the reason I got a great old house for a song and started this "hobby" in the first place...

Mike T., Swampeast MO

If you want...

...to create a system of exceptional comfort, reliability and efficiency and are willing to try some things that aren't exactly the "norm" consider the below. While some can be done without the others, please consider these as a system. All presume that the home is reasonably insulated and with reasonably low outside air infiltration.

1) Size the radiation such that the system return temperature will be below 140° at least 80% of the time. Size for as low a temperature as budget and space will allow.

2) Either use a condensing boiler or injection mixing with a non-condensing boiler.

3) Use TRVs on ALL radiators.

4) Use constant circulation and reset. Unless the home is utterly enormous, you need only one system circulator for the radiation.

5) Excepting rooms with an exceptional amount of glass or walls of glass, place the radiation on INSIDE walls in full "view" of the exposed walls. A reasonable amount of window "view" is OK. Try to keep the rads (iron or steel) taller than they are wide. Don't use extremely long, short rads in this positioning. The rads MUST be located where they will NOT be covered--either with enclosures or furniture. This positioning works very comfortably in my sleeping porch with windows about 75% of the floor area. 1922 windows (restored "better than new"), storms, NW exposure and 20' above grade but no drafts.

6) Use radiant floors in small, hard-surfaced areas like baths/laundry and possibly kitchen. Choose a heat transfer system that achieves the desired floor surface temperature based on the reset curve of the radiation and the construction of EACH of these floors. Run these "wild" off the heating mains with simple valves to adjust flow. In a large area like a kitchen first try it "wild" but install wiring for a thermostat and leave access to install a zone or mixing valve if necessary. In most cases the kitchen will require a radiator as well--the TRV will allow the floor to do as much of the heating as possible.

7) If using iron radiators, try to use the thin fin tube variety--especially in sleeping rooms.

Uni R

Why?

"Try to keep the rads (iron or steel) taller than they are wide. Don't use extremely long, short rads in this positioning. The rads MUST be located where they will NOT be covered--either with enclosures or furniture. "

Mike, I am curious about what is the rationale for taller than wider radiators? Is it just so that they don't get covered?

BTW, excellent recommendations.

Mike T., Swampeast MO

Low long radiators have LONG been known for high convective output.

All of those recommendations are geared to a purpose: enhance radiation while suppressing convective currents.

If you check "history" here you'll find a Canadian study to which I posted a link. In it they used low-temp panel radiators 2x as tall as wide. Radiant output was quite remarkable.

The inside wall placement suggestion is coming from a number of studies (formal and informal) that are finding such to be truly ideal AS LONG AS insulation and infiltration are both at reasonable levels. Proportional control and fairly low temperatures are KEY TO THIS and seem to be the VERY REASON that these studies have been conducted. The old notion that such placement results in an objectionable cold draft across the floor is not always true... The old timers also believed that window glass was transparent to heat in the form of infrared radiation--NOT true.

Peter Serwe

Tom Meyer

Any idea what zip code I should be looking for
Tom in? The find a contractor thing requires
a zip code.

Frank_3

Don't dismiss radiant just yet

If you understood the benefits of radiant heating to plan for it in the first place then you might want to consider an above-floor arrangement, such as the Stadler-Viega Climate Panel (a.k.a. Wirsbo Quik-Trak). It uses up only 1/2 inch of floor height so it won't have any significant impact on door opening sizes. It's also significantly easier to install than a joist-bay system.

I'm installing this in my home and have two rooms completed so far and I'm really very pleased. I plan on having it throughout the house. I'm using Runtal panel radiators in the rooms where supplemental heating is necessary.