Hot Water Heat question

Here you'll find a wide range of discussions on old-house topics.

Moderators: oldhouse, TinaB, Don M, Schag

Post Reply
beachbons
Posts: 47
Joined: Thu Feb 02, 2006 12:57 am

Hot Water Heat question

Post by beachbons »

Hello, all. We have a 100 y.o. solid brick home, built by my great grandfather, that is heated by hot water heat circulated through baseboards. The home is a 3000 sq ft. two story;additional full walk-up attic is unheated. Each level is heated by separate natural gas furnaces and each level has one thermostat. Furnaces are identical having been installed new in 1967. We are not in the home during the dead of winter; January to March.

The same guy who installed the systems has been servicing them every year since new. I've asked him if I should close rooms and close the louvers on the baseboard heat in those rooms to conserve heat. He said that since the hot water is running through the pipes anyway, if you close the room and close the louvers the room will cool enough so that heat will be transferred from the pipes to the cooler room thus reducing the temperature of the hot water and forcing the system to work harder. He said that by keeping all rooms open and heated the system works more efficiently.

This sounds counter-intuitive to forced-air systems where the closed hot air vents end before it enters the room.

We want to keep the home heated year-round as we are there through Christmas and we return early spring.

Thanks in advance for everyone's help!!

Lisa & Greg

Don M
Posts: 6965
Joined: Mon Dec 08, 2003 11:35 am
Location: Boiling Springs, PA

Re: Hot Water Heat question

Post by Don M »

I agree with your service person. The system was designed to run & heat all the rooms. Closing rooms off will decrease the overall air circulation & result in closed rooms being colder. As he said the hot water runs thru all the pipes unless you turn off valves which could result in frozen & burst pipes in those areas. That would also unbalance the systems.
1840 Limestone Farmhouse
Image

beachbons
Posts: 47
Joined: Thu Feb 02, 2006 12:57 am

Re: Hot Water Heat question

Post by beachbons »

Thanks, Don. Last winter I closed 60% of the conditioned space. This winter I'm going to keep all of the rooms open to see the difference.

Thanks, again.

triguy128
Posts: 708
Joined: Mon Sep 12, 2011 9:41 pm
Location: Keokuk, Iowa

Re: Hot Water Heat question

Post by triguy128 »

I'm confused, is this a furnace or boilers? It sounds like it has two boilers, but you just mistakenly called them furnaces.

Closing rooms doesn't really work. With forced air, you can starve the system of air and cause the heat exchanger to overheat. Closing at the register causes more air leaks, so more heat is lost in ductwork, which could be located in unconditioned spaces like the attic or walls. With central AC, you can freeze the coil or damage the compressor as well as use more energy since it runs less efficiently.

The only way rooms can be closed is if you have a true zoning system with zone dampers or valves and a thermostat for each room or zone.

With 2 boilers, you might try using a programmable thermostat and turning it down downstairs at night and upstairs during the day. Although this works better with forced air, not so well with boilers because they take longer to heat up and cool off.
1925 Neo-Classical

Previous home - 1968 single story Ranch/Colonial, 1200sqft - 11 windows
Current home - 1925 2 story Beaux Arts Neo-classical overlooking the Mississippi River, 3200sqft - 48 Windows

beachbons
Posts: 47
Joined: Thu Feb 02, 2006 12:57 am

Re: Hot Water Heat question

Post by beachbons »

Triguy,

Yeah, you're right. There are two separate units with boilers and, yes, I agree with you on keeping the entire system in balance with forced-air. Since the house belonged to my great-grandfather and his daughter lived there her entire life, 90 years, I'm getting conflicting "advice" from relatives claiming "Aunt Dorothy" closed off rooms to keep costs down. I'm hoping my keeping the temperature constant in the home this winter will keep heating costs down.

Thanks, again!!

Post Reply