My wife's parents built a house in 1986 and put in a ground source heat pump.

They always speak very highly of the extremely low electricity bills and cannot think of having anything different.

When if comes to comfort, I thn=ink the system rocks in the summer, but in the winter, it feels cold. (Now they keep it cool ~ 67-68) I don't know how the tstat is set, etc. It does seem like it blows cool air from the registers and does not give you the 'hot' register air like a gas furnace.

It the register temperature typically 'cooler' than a traditional gas furnace?

Is there something that they should be looking at or is this normal?

Thanks,

Ian.

ian ~
I'm sure one of the professionals will answer, but as a homeowner who just installed a system I can tell you how it was explained to me:  Geothermal will blow out cooler air than a traditional system but for a longer period of time.  This is what makes it more comfortable... you get more consistent heat rather than the ups and downs (typically a delta T of ~4) with a traditional system.  As a matter of fact, in the downstairs, I had initially wanted those vents that come out of the floor at a 45 degree angle (the angle between the floor and wall), but my contractor explained that you don't want the air to directly hit a person on the leg (i.e. at the dining room table) because the air will actually feel cool on the skin as opposed to the really hot air that comes out of traditional systems.  So, my vents come out of the floor and blow straight up, mostly under windows.

Gas heating system have duct temps of around 130 to 140°F. Geothermal duct temps are around 85 to 95°F. More air has to be moved with geothermal compared to a gas fired system. Comfort level on either system , geo or gas, depends on proper installation, sizing and duct work. I find the geothermal very comfortable.

Regards,

Ona hit the nail on the head

I believe in any system gas oil or geo the systems that are the most comfortable are the ones that you dont know are on

If you have a system ( in a retro fit , or less then perfect design ) that is blowing air on you and it feels cool adding a humidifier will decrease the evaporative cooling effect you sense

Increased humidity won't help with sensation of coolness from moving air - evaporative cooling only an issue when skin is moist

actually the skin is always moist , you sweat constantly it usually just evaporates , how much you sweat depends on your body's temp and has a direct relation to how quickly your sweat is evaporating , so to recap when your sitting on the couch and its 65 degrees and you haven't moved all day , your sweating . this drawing humidity from your skin will make you cooler and will show itself with bloody noses , dry skin , chapped lips .

This is why controlling latent heat is so critical to comfort

See heat index if you dont trust