'Mini-Split' systems? ? ?

[Ray]

I live in an 82-year-old six-unit apartment building, and the heat comes from a single furnace through steam radiators. Needless to say this creates a problem of reaching an optimum temperature. Not only are there wide variations in heat between apartments, but some like it hot, some like it cold.

It seems to me our best solution would be to establish a very low temperature level for the main furnace -- like 60 degrees -- and then have each unit provide their own supplementary heat to bring the it up to the desired level.

I've been looking at these "mini-split" systems which provide both air conditioning and heat.

Does that sound like a good solution?

I welcome any experience.

[DT]

While I am sure an HVAC expert can offer some advice as to the possibility of zoning the present steam system, I can at least offer some experience with the mini split. I just installed a 12,000 btu unit in my home and am quite happy with it. They install fairly easily as long as they can be mounted on an exterior wall with a place to mount the outdoor unit nearby. The longest line set I found offered on the units on eBay was 24', although the units themselves will operate with a line length up to 50' or so. And bear in mind that most mini splits have a single indoor unit, so it needs to be placed where the air flow can reach the whole area.

-- Dennis

[nicksanspam]

We solved a problem like that in one of 25 units in a 5 story co-op with a single thermostat in Brooklyn by adding a Danfoss mechanical thermostat and a humidistat and a solenoid valve and a needle valve off a T that went to a 1-pipe steam radiator vent. When the RH dropped, the valve hissed live steam into the room, scaring the cats.

A lot of the residents wore T-shirts and shorts and left the windows open all winter. The apartment air was extremely dry. There was no insulation on

3 steam risers in the unit we fixed up, and too many radiators. We took one out, insulated the risers and added the thermostat after the humidity T, and now there are only 24 units with the windows open all winter :-)

Yes. That way you get AC too, and you can turn off the split systems to get energy savings with a setback at night and whenever units are unoccupied.

Nick

[Ray]

Thanks Dennis -- That is very helpful.

[Ray]

[m Ransley]

It is not hard to balance a steam system within 2-3f with air vents such as Gorton, they have maybe 5 different ventings avalaible, it takes time, going in each apt, monitoring temps, and changing out vents keeping a log, but the payoff is in reduced heating costs , even temps.

Nicks boiler provided humidity adding idea is the dumbest thing you can do, it decreases boiler efficiency dramaticaly. The last thing you want is to constanty add cold winter water to a hot boiler. Lanlords that know boilers spend alot of time fixing leaks and evicting idiot tennants that want free humidity at the lanlords expense. I have evicted a few that removed vents for humidity. Again nick your idea hurts the lanlord, wastes gas, its not a green idea, its greed and dumb.

[m Ransley]

Add an electrical heat source, when for my area electricity is still

50% more per BTU doesn`t make any sence, it will cost you time and and money to balance your boiler, but less than 1 split system, it is something a lanlord must learn.

[Goedjn]

Without fiddling, I don't think that will work.. If all the units are running their own "supplemental" heat, then no room is below the 60d temp for the main furnace, and so nobody will call for heat, and the main furnace won't run at all.

It seems to *ME* that the best solution would be steam radiators that are adequate to provide the highest reasonable temperature, but which can be throttled back by the end-user somehow for people who want lower temps.

Maybe louvered radiator covers and electric fans? Is this a one-pipe or a 2-pipe steam system?

With little or no insulation between units, a person who likes it cold sandwiched between people who like it hot is still going to have to open a window, though.

[Ray]

Thanks -- very helpful

[mrsgator88]

Responses inline....

Are you in Chicago?

How many like it hot AND want the windows open?

I'd find a way to give each unit their own complete hvac and dump the boiler.

S

[nicksanspam]

I disagree, and I have numbers :-)

Nick

[Nick Pine]

Can you say "heat pump"? I have numbers, and I can spell :-)

Nick

[m Ransley]

Post numbers nick we need your numbers.

[m Ransley]

Can you say "Split" nick, OP said Split system, can you read.

[Goedjn]

Well, if you're going to re-do the whole system, Burnham's duo-rad system looks good to me. Centrally supplied hot(cold)-water, and fan-driven radiators at point-of-use. If you're willing to use 4 pipes and equip the end-user with a some valves (does anyone make DPDT valves?) then one apartment could be running the AC while the one next door is running heat.

[nicksanspam]

I'm afraid you are incapable of understanding them.

Your arrogance seems to exceed your ignorance :-)

Nick