It sounds as though your basement is similar to ours. When it is really cold outside and the furnace is running extensively to warm the house, our
basement gets toasty. We found the greatest discomfort in the basement being spring and fall when neither heat or A/C is called for upstairs.

Be sure to install cold air inlets near the floor in your basement. This will remove the coldest air and also, when A/C is operating, remove humidity from the basement whenever your main system is operating.

Yes, electric heat is more costly than gas but you will only be using is as auxulary heat, not the main source so your cost will be nominal. Baseboard is a viable sublimental option.

Actually, I did not add any additional vents or ducting when finishing ours. There is only 1, 6 x 12 vent in the finished area. I did install an electric fireplace which offers the option of heat with or without a "fire". It takes a chill away in just a few minutes.

Some photos of ours are linked from "My Page". Good luck with your project.

NO, our heat pump does not provide any heat in the winter l ike your boiler. If so, I likely would not have a problem. I wish I had gas!

There is nothing down there now so far as vents go. The 55 - 65 degree range is just what is naturally occuring n the unfinished basement.

...I wish I had gas!

I was gonna suggest a gas fp or stove. You'll likely need a zone heating solution.
I added a gas stove, and the basement gets nice and toasty.
I now realize tapping into the central heating does not produce enough heat in my case. Too bad I spent the money.

andrelaplume2

Sorry, I do not have a heat pump, or a boiler; just a forced air system like most in our area. Only one aquaintance had a heat pump many years ago and part of the system was a large air distribution chamber in his basement about the size of a furnace. As I understand it, heat from coils within the chamber was released and circulated warm air through ducts. The air was not as warm as from my furnace, but sufficient to provide comfortable interior temperature.

That being said, I believe what I mentioned in my earlier posting would still be basically correct. Keep in mind that cold air settles and warm air rises. Extracting the cooler air from the basement will have a warming effect there.

Obviously your heating contractor who is about to upgrade your system is a more knowledgeable source to assure that the system is properly sized to perform as you want. Other auxulary heat sources are still an option for the basement. Hope you get the information you need to finish the basement and be comfortable.

IMHO you are still heating/cooling the same volume (unless there is insulation between the basement and 1st floor). As others have said, build in an air return at floor level. We also added supply lines from the ducts but instead of cutting a hole overhead, we ran the supply to floor level as well. Instead of warm air blowing on your head, you get warmer air at the "colder" floor.

In the summer, the supply vents are closed in the basement, and opened on the 2nd floor. In the winter, most supply vents are closed on the 2nd floor, while the basement is opened up. Works for us, your mileage may vary.

HA! There IS insulation in the basement ceiling joists.

I just had the hvac work done in my basement. I added duct work and dampered zones to the existing system. Yes, it was more expensive than punching holes in the existing. However, my basement will be finished like the rest of the house. It will add value. In my opinion, the biggest mistake people make when finishing a basement is to not have it on a par with the rest of the house. It's the difference between a finished "basement" and a finished "lower level".

Agreed but cost is a factor. At this point I'd be happy with a warm finished lower level.

That is a big space, 750 sq/ft will require several registers and returns. I don't think I would make it a separate zone. In my experience, nothing will work well unless you keep the air moving. Hot air rises and cold air sinks, no matter what you do. If you have enough registers/returns installed, I would recommend running the fan continously on your system. It will level the temperature in whole house not just the basement. I use a thermostat where you can program the fan, the same as you can program the temperature so you can turn the fan off when your at work. It also has an in between setting called "circulate" which runs the fan 33% of the time regardless of the heat/AC load.

yea, I suspect I'd need at leat 2 returns and 4 registers....I fear how that would affect the current system; perhaps I'd need a new larger main trunk or something....maybe the baseboards are looking better...or some other type of stove or somehing.

A ductless split heat pump would work well. Check mrslim.com

i sthat in addition to the regular heat pump...ie an add on to the current system...what does this cost?

Sounds like alot goes into the thought os heat and air! I have abasement I would like heated and cooled a bit in the winter just to keep mold down (or i couild use the dehumidufier we have for the cooling because it is cool down there). The kids are miving back (grandchild and aLL) AND we want it warm down there. tEMPS HERE IN gEORGIA DO NOT GO LOW FOR LONG. Cost efficiency and heat is our concern (with three kids in college) would the heat pump, the electric baseboards, an electric firplace, be best? It is a small basement (less than 800) with a room already done (plug in heat) and two left to do. Before we get to work on it we need to decide on the heat flow and perhaps even the cool flow for summer. The ceiling is insulated and the unit would be just for the basement.
Other questions: are registers and returns necessary in such a small area?Or ois that depending on the type of heat used?

I put vents in the actual rooms and one of each in the open area which most will stay an open floor plan. I did install a pellet stove for heat that is nice and cozy after being outside freezing all day at work. It is also part of the back up plan in case of an ice storm or other long outage in cold weather.