Heating / Cooling a four season room

mowernySeptember 16, 2007

I recently moved into a house with a 20'X14' 4 season room built in the back. There is no door that can be closed in order to separate it from the main house. It is built on a concrete slab (although I think there are joists and insulation that the plywood sits on) and has no access from underneath and there is no living space over it. You can access the attic space via a vent from the outside. Also, it has a beautiful new ceramic tile floor that I do not want to rip up. The room is not heated nor cooled, although it is insulated, and we have been using it as our main family room/TV room etc and we use it continually. It has four sets of sliders as well as some regular doors with glass and a casement window. Needless to say the heat loss in the winter is probably quite large (I would bet 15,000-20,000 BTU) It gets rather cold in the winter and hot in the summer. I've been researching and speaking with HVAC contractors for a few months trying to figure out the best way to heat and cool this room. I have baseboard heat throughout the rest of the house. Owners probably two before me had installed a 1/2 inch supply and return line that comes up through the floor about half way down the length near one of the sliders, a thermostat, and zone valve with controls, and I suspect may have had a cabinet heater there at one time? Currently the supply and return lines are capped. Can anyone suggest a decent yet cost effective way to heat and cool this room. One option is to put in a cabinet heater and buy an air conditioner that fits in a casement window. Probably not the best looking option. One option would be a split ductless unit that is also a heat pump. (I've read that these kick into electric heating elements once outside temp drops below freezing). And one option that was suggested was to install a unit in the attic space that is hydronic for heat and then acts as a central air conditioner with an outside compressor in the summer. It would have registers installed near the outer walls in the ceiling. That option, is probably the cadillac of options, but would cost $7,000, which is much more than I want to spend to heat and cool one room (albeit probably the most used room in the house). Any suggestions, or manufacturers of equipment, would be most helpful. Thank you very much

Thank you for reporting this comment. Undo

I have a similar room I'm procrastinating on dealing with and agree that the hydronic/air handler combo would be the best.

I can't imagine that the split ducless will heat effeciantly/effectively but I would probably go that route knowing that I may have to suppliment the heat. Perhaps using the existing loop.

The only "nice" / effective way would be radiant which doesn't seem to be an option for you. Do you have any exterior wall for electric baseboard?

    Bookmark   September 16, 2007 at 11:33PM
Thank you for reporting this comment. Undo

I think you need to get an energy consultant to verify the
insulation values of the floor and ceiling and make sure
all the glazing is double or triple pane. Repair any old or
damaged weatherstriping so that the heat loss is minimized
in addition to adding heat. This seems to always get over-
looked in older homes and added or remodeled rooms.
Your local utility may provide this service free or at a nominal
charge. Or they may provide a list of certified contractors.

    Bookmark   September 17, 2007 at 7:42AM
Thank you for reporting this comment. Undo

Chrisny, thank you for your opinions. I was hoping beyond hope that I would be able to get under the floor to install radiant heat, but no such luck. And I really don't want to rip up the beautiful tile floor. I only have about 6 feet of exterior wall space in which to put baseboard, so that wouldn't be an option. All other exterior wall space has either doors or sliders. Any thoughts about a 20000-30000 BTU cabinet heater? Do you think it'll cover the room enough to keep all areas fairly warm?

    Bookmark   September 17, 2007 at 8:29AM
Thank you for reporting this comment. Undo

Does anyone else have any suggestions? Does anyone know how well the stand alone gas fireplaces work (the ones that look like wood burning stoves)?

    Bookmark   September 18, 2007 at 6:32PM
Thank you for reporting this comment. Undo

We had one of those ventless gas fireplaces. They heated really well. My only prob was the gas gave me a headache. I don't think this is normal for most. We've had tons of people over and nobody else had a problem.

    Bookmark   February 19, 2008 at 1:12PM
Thank you for reporting this comment. Undo

I have a room like this, it sucks the heat out of the house in the winter and overheats it in the summer.
I have put a large thick curtain across the opening to the room and only open it when it is beneficial (sunny days in the winter, at night during the summer)
I was thinking about a woodstove because it is so expensive to heat and cool with propane and electricity.

    Bookmark   February 19, 2008 at 1:59PM
Thank you for reporting this comment. Undo

We bought a Soleus Air ductless air conditioner for our four season room, it's soo quite and it has the Inverter that makes it very energy efficient. We bought it online from www.EcoAirandWater.com and had a local contractor install it. We told the contractor we got it as a gift from my brother, because the contractor wanted to sell us the equipment. We saved $1000's...

Here is a link that might be useful: Ductless Air Condtioners

    Bookmark   March 27, 2008 at 8:37PM
Thank you for reporting this comment. Undo

For a 20'x14' room with three exposed/outside walls you should be looking for a 11,200 btu heater as a minimum and possibly as high as 14,000 btuh. That would be 3.5 Kw to 4.0 Kw electric heater. The above mentioned A/C units are not as efficient as a Mitsubishi ductless split system at 16 SEER. See link.

Dan Martyn

Here is a link that might be useful: Mitsubishi ductless Split system - Model M

    Bookmark   March 28, 2008 at 12:30PM
Sign Up to comment
More Discussions
Does Air Duct Cleaning really help?
We live in a 40 year old home with a forced air gas...
Need help with selecting Eff Heat Pump replacement.
20 yr old American Std Heat Pump stopped working. ...
Geothermal in new construction.
Our house is currently under construction, and while...
HVAC billing question
Question for the pros...... So I had a faulty capacitor...
Who do I call about a whole-house fan?
I'd like a whole house fan. This might be a DIY project,...
© 2015 Houzz Inc. Houzz® The new way to design your home™