Solarium?

See builditsolar.com. Lots of stuff. Just beware of pie in the sky stuff from yahoos who built one thing and talked about it before problems surfaced. Also, if you build a solar addition, know that it'll get a lot of sun and overheat overheat without measures to moderate the solar gain. Consider exterior shutters/shades for warm season and, to a lesser degree, interior thermal insulation for winter. Do not glaze the roof. if you do, expect very high summer temps. Also know that vertical glazing will be easier to keep moisture and leak tight(er). Paint/stain the concrete a dark color. That'll help moderate interior temps. and even out the temp. swings some. If you've built a screened porch, do the same w/a solar addition, just use studded walls and double glazed windows, some of which are operable for ventilation. Make sure to be aware of and follow local building codes. They exist for a reason.

Good luck.

I've looked on BuildItSolar for other projects, but didn't think to look there for solarium plans or ideas. Will do.
Why don't I want to glaze the roof. I want a waterproof roof, not a leaky one. When I speak of glazing I'm referring to the glazing around each window pane that seals it to the wood. The stuff that cracks and needs replacing ever 10 years or so in the old style windows.
In order to keep summer temps down my roof windows will open and a tarp or greenhouse type shade will be placed over it.
Don't want a black floor. It will burn my tender feet. I hope to have a decent tile floor. This space is more for living more than for heat.
If I build it like a porch, as you suggest, it will just be a sun room, not a solarium. My porch, with it's solid roof, gets nothing but shade and it's right beside the location for the solarium.
Thanks for the comments.

You're welcome.

As you wish. Stuff I've suggested has, for the most part, stood the test of time, and separately, FWIW only, been J.P.M. checked as valid by construction, observation and measurement, and found to be valid techniques to help make sunspaces more comfortable and livable with respect to temperature comfort, moderation and at the same time heat retention.

BTW, I use the word "glazing" as synonymous with "Window", as in, don't put windows in the roof unless you want more overheating in the summer and more heat loss in the winter. Roof windows that some call skylights, tend to leak more and be more troublesome than glazing in vertical walls. It's mostly the gravity thing. My observation is that tarps over surfaces when more than a temporary fix are not viewed with universal acceptance. That's one reason among many why I don't suggest them for shade control.

There is a wealth of information in the form of books, many at least 40+ years old. See the local library.

I'd start with a title "A Golden Thread. 2500 Years of Solar Architecture and Technology". Butti and Perlin authors. Copyright 1980. ISBN # : 0-442-24005-8. Published by Van Nostrand Reinhold. Chap, 1 has a lot about architectural tricks to heat dwellings that have been in use for thousands of years, a lot of which are still used in modern sunspace construction. Most of this stuff is not rocket science. Basically, Use a lot of insulation and thermal mass. Moveable insulation for glazed areas. Make heavy stuff (like concrete floors) dark to absorb heat for later release. Make lightweight stuff light in color to bounce light around until it tits something dark.

Good luck.

Here's a useful tool to help you in your initial design for roof overhang. Proper overhang design will help keep your room usable year round.

As stated above avoid roof windows, as they are not worth the additional cost or problems that they create: such as condensation and heat loss in winter, and overheating in summer. In winter the sun is to low in the sky to offer any advantage.
Installing radiant tubing or electric radiant in your slab before you begin construction is my #1 piece of advice. Throw and inch or 2 of Dow insulation on your existing slap add your tubing and pour a thin slab on top. This will make all the difference in usability during the cold months. The radiant tubing can be run off your water heater if you don't have an existing hydronic system.

FWIW, +1 on the overhang. I did find exterior shades to more effective however. Just sayin'.

On hydronic slab heating: I thought the slab was staying after resurfacing last year. If not, and hydronic if heating is used or added, I'd suggest to not expect any new slab, depending on thickness to respond to any heat input in a rapid fashion, more like in a time frame calculated in hours rather than minutes, either heating or cooling. That means some time management of the heating thermostat. Some slab thickness is required. Otherwise, cracking will be a problem sooner than later. Thicker slabs mean slower heat response.

One example of many situations.: 8 A.M., winter, cold. Turn up thermostat. Heating begins, but due to thermal mass, effects of the heat input bottom up are not felt until noon. Now, say the sun's also been heating slab top down since 9 A.M. and the hydronic thermostat doesn't know about it. So, the slab is now hot. Room is now overheating and staying that way till past dinner (maybe). One solution: Fire up the thermostat at 4 A.M.

Using thermal mass as a heating/cooling adjunct or tool can be useful, but some understanding of how it works and the consequences of thermal mass are helpful to get the most out of it, or at least not self create a PITA from lack of information about how such things work and the consequences. It ain't necessarily your mother's heating system.

Also, depending on the heat loss of the new construction, and the size ( BTU input) of your water heater, it may run more than designed for and fail prematurely. Or, depending on thermal management, if off-setting any existing dwelling heat load is a goal, the opposite effect may be obtained.

Radiant floor heating is not designed to be adjusted, it's designed to be set and forgot, night setback is not recommended. A properly designed system will utilize an outdoor temperature reset controller that will control the temperature of the constantly circulating warm water through the slab and turn off the system at around 60-65 degree outdoor temp. For a simpler and less costly system a hot water tempering valve can be used to set the temperature of the water entering the slab ( not recommended ).Usually a setting of 62-65 degrees F at the thermostat meets comfort requirements or a sensor can be installed in the slab to maintain the set temperature of the slab.
The slab is capable of emitting 40-50 btu's per square ft and should be more than enough to heat the room without taxing the water heater. Radiant heatloss calculations do not consider infiltration or duct loss in the calculation making the losses less than conventional heating.
Constant circulation + outdoor reset=maximum comfort.
In my opinion the only way to heat a room with a slab.

I believe I'm pretty sure I understand what you are writing but not sure I agree with all of it. However, I kind of doubt most anyone other than you and I either understand or care much about the subject, so, if it's OK with you, I'd prefer to leave it at agreeing to disagree and not get into protracted discussions that resolve nothing. There's bigger fish to fry around here.

Well, thanks again for the replies and suggestions. I won't be installing radiant heat, or any heating system for that matter, except maybe for a black drum of water for thermal mass. As I mentioned in the original post, it's a three-season "living" space that may also have potential use as a greenhouse. I don't need it to be comfortable for "living" 24/7. It will be a low budget project. I won't be pouring a new slab over the existing one.

I would love to see more of an explanation for the recommendation of a solid versus a transparent) roof in terms of warming the space. I have such a roof on my screen porch on the same side of the house and it doesn't get much light due to the solid, mostly flat roof. My house is one-story. The roof of the solarium will have to be flat or nearly so.

I'm also realizing that the lfour arge pine trees on the boundary of my yard may block more light than I realized. To that end, once I get a sunny day, I will be comparing solar intensity measurements at the pad, versus in an area that isn't blocked by the trees, and aso on the screen porch. I don't have a fancy meter, just a pyranometer app by hukseflux. It will provide measurements in W/m2. I won't know what they mean, but at least I can determine if the trees are going to filter out too much light.

On the trees and measurement of irradiance and shadows, keep in mind that the sun's location/position changes constantly. The shadow cast today at 0900 hrs. won't be in the same location as the shadow cast by the same trees/objects at 0900 hrs. on, say, 12/21.

Also, because the sun is lower (more southerly or less vertical) in the sky when it's cold (winter), horizontal or mostly horizontal surfaces (like roofs) will see less insolation (sunlight/solar energy) in winter than vertical or high angle surface will see in winter. Also, and probably as or more important in cloudier/northern climates with longer nites/shorter winter days, an insulated roof will lose less (or retain more) heat that a glazed roof. Less heat loss at nite will mean a warmer space in the morning with less heat needed to get to a more comfortable temperature. Vertical and mostly equator facing (south facing in the northern hemisphere) glazing will see more insolation in winter than horizontal surfaces. The opposite effect applies in summer with horizontal surfaces seeing more insolation than vertical surfaces. That's the other big reason, and perhaps the biggest reason to avoid horizontal glazing of surfaces for sun tempered spaces - a glazed, horizontal roof will tend to cook any enclosed space under it as the solar zenith angle decreases.

A respectful suggestion: Scour the net and look for any number of semi technical books about sunspaces and solar tempered dwellings. There are many. One of the first books about solar energy I acquired was " The Solar Home Book" , Bruce Anderson, ISBN # 0-917352-01-7. Copyright 1976 and long out of print now, but a library may have it. Lots of good stuff that's a bit technical but explained well and presented in a very understandable and readable way. Useless/off topic personal note: That book was a gift from my 1st wife that I credit with infected me with the solar bug. Been at it ever since.

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