Originally Posted by
motoguy128
...and your point is. That's normal. All building through out hte world see low sensible load conditions at nighttime. However in your climate up north, latent load shouldn't be an issue except for a few weeks in winter.
I'll repeat it again. The ONLY way you can precisely control building load with a 10:1 ratio is hydronics using chilled or hot water on smaller scale (below 6 tons). End of story, case closed, no point in digging further. Now, at 6 tons, you could install 2 zoned inverter driven split systems (like Carrier Greenspeed) and each only runs at abotu 30% capacity and you get 15% between 2 systems.
Even with chilled water, the chiller will still only turn down to about 75% capacity and the boiler typcially 5:1, but you can use a storage tank in either case to prevent short cycling.
In you climate, actually, it's possible to do radiant floor and wall cooling. If you have high mass floors, here also a way to prevent short cycling. Then you just need a dehumidifier or HRV for dehumidification.
Finally on the point of a "cold blast". If the equipemnt and ductwork or with mini splits, the indoor units are sized properly or located correctly then there should never be a cold blast from the equipment. In my home even on high stage in heating or cooling, the home never feels drafty. In cooling mode you can feel the cool dry air a little if the system is in a dehumidificaiton on demand mode (lower airflow). But it's actually refreshing and not cold at all.
A properly sized and installed HVAC system is silent, heats and cools evenly, even at low load conditions, and never short cycles, unless it's a small home with out much mass in the building materials. Some homes will short cycle in low load no matter what you do. The space jsut doesn't have enouhg volume or building materials in proportion to it's peak heat loss ang gain. Remember, a smaller home have more surface area to volume and mass ratio. So they have more temperature and load diversity. A larger home with plaster, stucco, tile, hardwood, etc, can take a hour to warm up or cool off even 1F on a fairly hot or cold day. That means when the system comes on, even with no load, it can take almost 10 minutes to raise or lower the temp 1F, which a good controller will maintain if it can stay under 4 cycles per hour maximum.