Floorplans and Heat

qzmpxio

I am wondering what is the most - or least effecient home floorplan for energy usage.
I am prompted by ever skyrocketing heat utility bills in my single level 3000 sq ft ranch home in Denver. Although my energy USAGE year over year continues to go down with continual improvements to insulation, heating system, weatherstripping, etc, the actual dollar cost is approaching astronomical limits with $400-$500 monthly bills not uncommon. In part I can thank my local energy company for their constant price increases, but when I compare my bills to others in this area with similar sq footage, I am shocked at how high my costs are.
My conclusion has led me to believe that it just isn't very cost-effective to heat a single-level (no basement, no 2nd floor) home as compared to a multi-level home where some of the heat from the lower levels can flow to the upper levels. Any Comments? Or should I continue to pursue more efficient heat and insulation options?
Thanks

jaw22

What specific improvements have you done to improve efficiency? You want to make sure all the things you've done are actually working as well as possible. Are others near you running their houses at the same temp? Have you thought about having an energy audit?

qzmpxio

I'm no newbie to home improvements. For energy improvements I have
1. added / split boiler zones so unused areas of the house could be kept a lower temp.
2. Installed a high efficiency Forced air/gas system (the old boiler system still seems to give the lowest energy usage).
3. Added attic insulation to 15"- the walls are already insulated.
All the windows are Anderson double-pane wood casement.
4. Added caulk expansion foam, and weatherstrip everywhere that seemed even slightly drafty.
5. Added vinyl siding which included an additional layer of foam insulation to the outside.

I have not tried an energy audit yet - but that might be a good idea.
It just seems like I am approaching the point where there are at least no really big improvements left (other than a 90% efficient boiler - and at $14k price tag - that one will have to wait).

My house footprint is the whole 3000 sq ft and it seems most multi-level houses take less of a footprint and can share some of the heat loss from the lower floors.

jaw22

DO you have 2 heating systems? You say you upgraded to a high eff forced air furnace but now want a new boiler too/? How will that save you money. Is you house built on a slab and is it insulated? Have you airsealed all existing attic bypasses/penetrations in the attic with foam? What kind of insulation do you have in the attic.. cellulose?
In theory you are right 2 stories get some heat from below but in practice most houses have a higher heat loss/load and insulation problems on the 2nd floor that many times isnt taken into account when sizing a heating system. Many insuallers just end up just putting in 2 systems

qzmpxio

Thanks for your tips - you must have some good experience in the hvac industry.
I should do a double-check of the attic for air leaks, and the energy audit is definitely a great idea.
My place as you may have already guessed is an older home build in the late '50s and had boiler heat when I moved in 8 years ago. I have since added central air - which only makes sense for the small additional cost to put burners in that air handler - so yes there are now 2 complete heating systems.
Since it is an older home - it has relatively low ceilings so there is less air space to worry about.
the house is built on a crawl-space which is about 3 ft deep, open dirt floor and r13 insulated outer walls. The attic is a combination of rock-wool and cellulose, the walls are blow-in insulated.
I wonder if insulation to the subfloor would help?
The subfloor is 2.5" thick solid (2-6 T&G with 5/8 plywood on top.)

My other thought was to somehow 'close-off' about half the house in the winter - effectively making it 1500 sq ft to heat, But the wife would never go for that.
As for inside temp - we keep t between 64-66 degrees most of the time with occasional few jaunts up to 68, but no higher.
My boiler guy said the set-back thermostats don't really do that good for boilers, and I must admit I have found that to be true.
If I do decide to get a new boiler in the future - what do you think of Allied Saturn series - 83% efficient.
thats what the boiler guy quoted me for