HVAC questions

[chim]

We have around 2,700SF two story with 6" outside walls and extra attic insulation. The 95% efficient 100MBTU Trane LP gas furnace keeps us comfy and since we buried a 1,000 gallon tank we can buy when the price is down. Generally costs us about $500 per heating season. Wifey watches the prices and buys when it's close to $1.00 per gallon. We're coming to the end of the heating season and there's 35% left in the tank. When filled, it is about 85% full.

Cooling is with a DX coil in the furnace plenum. Love this setup.

 

[radios1]

Isn't it a little bit costly?

if you can dig the trench or holes, not much, that's where the cost is.. some areas you can get away with just a deep trench, others you'll need a well drilling rig to get down deep..

 

[not2old]

We have an abundance of water here, only 22' down, which makes an open loop geothermal system even more efficient without the cost of installing the ground loop. Only once have we experienced colder than -25C for a few days and it didn't seem to make any difference to our heat. Another bonus is that air conditioning is even less expensive to run. My system recovers heat for the domestic hot water as well. I think it's the way to go if you have the water available.

 

[radios1]

100MBTU is enough for a large palace, I'm sure you meant 100KBTU..

 

[chim]

Maybe somewhere, but the schedules I'm accustomed to seeing on drawings follows this:

BTU to MBTU Conversion - Convert BTU to MBTU (BTU to mbtu) - Energy Conversion

www.theunitconverter.com

 

[JM7500]

1 ton = 12,000 btu/hr. 1 ton can cool from 300-750 square feet. It's worse to oversize your air conditioner than underside. If the unit is too large, the unit will short cycle-while the air will be at a good temperature, the unit doesn't have time to remove the moisture from the air and your humidity will be high. Humidity plays as part of being comfortable as the temperature.

 

[Handloader109]

I just installed a small mini split from denville 18kbtu unit for my basement. I work down there and it gets cold. Our main HVAC wasnt really set up for doing more than keeping the basement from freezing as no ducts outside area near the inside air handle. And the unit is really undersized for the house. I looked at a bunch of options, and as we are down to electricity or propane, I went with this mini split. Drilled through my 8 inch pored concrete wall, and pored a pad. installed, checked it out for leaks and it works. Very well I might add. It is rated at a -20f still to provide heat. It has warmed up, but I cranked it up at 45 outside with it being 60f in the basement and it put out 95f air.

 

[yanmars]

Good to hear.

 

[Frankenkubota]

I've been reading about how heat pumps work for a long time.

I know they harvest the heat from the outside air, even when it "cold" outside but..........

Seems to me most the heat is generated when the gas is compressed?

 

[dodge man]

Freon goes through a phase change in heat pumps, ac units, dehumidifiers, and geothermal units. When things go through a phase change they release a lot of energy. In the case of Freon a gas to a liquid, and a liquid to a gas. You compress Freon it gets hot, you blow air over it, you get heat in your house. In that process it gets cold, you put that cold outside and blow air over that is warmer, compress it back to a liquid and start the process over again. During the summer the process flip flops and the heat goes outside and the cold inside.