Individual Gas Heating Units
I am renovating a brownstone with four rental units. I am going to switch from oil to natural gas for the heat and hot water. I am considering installing individual natural gas furnaces and gas meters for each rental unit. Programmable thermostats will give tenants direct control over their heating costs. Has anyone had any…
I am renovating a brownstone with four rental units. I am going to switch from oil to natural gas for the heat and hot water. I am considering installing individual natural gas furnaces and gas meters for each rental unit. Programmable thermostats will give tenants direct control over their heating costs. Has anyone had any experience with installing such units? I have been quoted significantly different prices by two plumbers for the heating units themselves. I am curious what others have paid for these units and for the labor (per unit). The brands I am considering are Weil-Mclain, Goodman, and Trane. Does anyone have any knowledge about the quality of these brands? Thanks in advance for your helpful comments.
Forced air will probably be nearly impossible to set up as a per apartment heating basis.
You’d probably really need to convert to a hot- water-return or steam radiator system to create have apartment heated by its own furnace….but frankly, DON’T do it. Bad idea because of all the piping, disruption, wall breaking, ugly radiators, etc., etc. Just stick with forced hot air and factor the cost of heating the apartments into the rent you charge. Unless you desperately want to get rid of the forced air system for other reasons…just leave it. I hate forced air but I would probably not replace it if I bought a house with a decent forced air system already in place…plus, it is possible to use it for air-conditioning if you’re into that…
BEFORE anyone installs a new furnace or heating system, do a home energy audit and even use go the route with a professional using an infrared camera. I don’t know if you really need to do a blower door test since our houses tend to be very permeable. So what…we can’t do much more than caulk where existing surfaces meet or, in a renovation, properly detail how drywall sits on studs and insulation blocks airflow patterns…insulate the roof very well (And do I hear “green roofâ€, Anyone? Most have a layer of insulation as part of the installation.). Figure out your window and door weather-stripping issues and the ameliorate problems.
Basically, you need to figure out exactly what your heat load needs to be.
With our older houses in Brownstone Brooklyn, one of the big heat vacuums is the windows. Please don’t run out and order new windows immediately. Do your research. The best bet right now is triple glazed windows of course…if they work in the space available. Double-hung windows that are manufactured with the upper sash fixed (non-movable) are more energy efficient (though you don’t see these much, they do exist). Fiberglas frames are more energy efficient you’re not likely to see them popping up in Bklyn much. Lots of stuff out there. Wood still works great!
DON’T get vinyl or aluminum windows (at all) but if you must…make sure the sashes are insulated. You can even think about storm windows…and if you cannot commit to anything, just use that sheer shrink-wrap plastic that heat-stretches over the interior of windows and skylights. This really works. Apartment dwellers can do this. Creates a more comfortable environment and the interior air does not dry out as much during cold snaps. And, in apartments, it is often hard to change windows…if you’re a renter there is little you can do other than this shrink-wrap plastic route…and if you’re an owner of a condo or coop, you probably cannot change the windows on a whim.
Old time techniques help too:
Make sure flues are closed in fireplaces…and if you can go the route, use the chimney stack closers that close the flue at the top of the chimney outside remotely.
Weather-stripping that isn’t too elaborate works too. If you want low tech, use the felt tape from the hardware store and attach it where the door meets the jamb, windows sashes meet the frame…stuff it in-between where older sashes meet if there is a gap…on double hung windows that are still on ropes or chains, stuff foam tubes or other compressible products into that gap on top of the bottom sash where the rope or chain goes down along the sash run.
Lots of “et cetera†on weather-stripping…do your research. If worse comes to worse, try good old Mortite putty which is a putty string on a roll. You pull the strings off and press them into gaps where surfaces meet. It can cut down on air blowing in.
Try to cut down on drafts in general. Anything that allows warm air to escape upstairs (roof hatches, skylights, cracks at baseboards, windows, open flues) and gaps downstairs letting air in (around entry doors, windows, etc.) create a stack effect which pulls air right up and out of the house so you end up heating air that’s doing not much more than escaping into the heat island that is NYC. Result: the lower floors seem really cold when the upstairs is hot and the tenants open the windows during the heating season because it’s stifling.
Window coverings and/or letting in sun appropriately and other techniques:
Make sure to have insulating drapes or somesuch on north-facing windows all the time in cold weather…and always at night
Draw back/raising window covers/treatments (drapes, shades, blinds) on sunny days in winter if the windows are south-facing and get good sun for a number of hours in the day.
You can even try a black mesh cloth available from cleardome.com or dot net or whatever it is. The company’s in California. But you can probably find this elsewhere—it’s similar to shade cloth used to really hot/sunny climates to shade plants that cannot take the climate/sun exposure. The mesh sold by Cleardomel works well as a light/infrared absorber that radiates long waves that have a harder time escaping out the windows. Heats the air and the windows get much warmer with the sun on them than without the mesh. When the windows warm up more than the room they cease acting like vacuums. The higher temps (90 degrees and well above) create a heat zone by the windows doing two things:
–The windows cease to act as infrared absorbers so you feel warmer near them–when windows are cold, they do not reflect heat back at you that you radiate out in the room and you feel colder…believe it or not, during the heating season, in two different rooms with the exact same air temperature, we perceive ourselves to be noticeably colder in the room that has single glazed windows as opposed to one with double glazed windows. It’s all about surface temperature.
–The warmer window surface brakes the regular cycle of normal wintertime window cooling in which air becomes frigid, drops down the window surface of the glass, sending freezing draughts across the floor causing discomfort and dwellers rushing to the thermostat to jack it up (or tenants complaining about lack of heat).
…Of course, not many people want black mesh curtains in wintertime. At least the shrink-wrap plastic over the windows works toward the same end though it does not create a real heat pool around/radiate heat like black mesh curtains in a sunny window.
ANY method you use to keep the interior glass surface temperature higher will decrease draughts.
One thing we all should learn about, but is VERY hard with our older housing stock in NYC, is the Passivhaus system. It is much easier to work Passivhaus design into new construction but also the typical wood frame free-standing house in North America can be retrofitted. The Passivhaus concept entails super-insulating, creating excellent air-tightness and installing intake, output vents and air-handling heat exchangers. Often there is no need for any radiant heating system. The incoming air is warmed by the exiting air in the heat exchanger. It is brought up to warmer temps if necessary before it hits the rooms…and when temps are well below freezing, the intake air gets a little heat before it gets into the heat exchanger to prevent damage to the mechanisms.
Unfortunately, this is system will probably not work on our Brooklyn Brownstones which have massive amounts of air blowing through them (even if we don’t realize it) and cannot be hydrophilically isolated from the ground, meaning: the walls need to breath, there is not enough room a thick layer of insulation, and walls cannot be retrofitted to be airtight. Even if one uses something like injected foam insulation, a water vapor barrier is created which causes lots of problems on both side of the barrier.
So…
Good luck with your heating work.
AND remember, each gas unit needs its own flue!
I’m thinking (dreaming) of installing a masonry heater/stove someday which could even heat water…some day…will probably need a footing built in the basement all the way up into the ground floor kitchen to support the weight. Hhhh. Would be great! Would have a bread oven…just such a massive job I’m a little scared off!
fort-GREENE-living
I am thinking of doing the same thing, but we have a forced air system in our home. Do anyone know if we have to convert to radiators or another system?
I own a 3 family with separate heating and hotwater. I’m in the duplex with two rentals above me. They never have to turn on their heat because my unit heats their apartments. Keep that in mind when charging rent.
Does this price of $7500/unit include the the piping up to each floor and the radiators? I would guess so….
A 130,000 btu unit will heat a 4,300 sq. ft. space very efficiently.
Mr. Hancock, are your boilers the modulating kind? If not, they are the home-heating equivalent of a Hummer.
The big Hummer.
A 22 x 64 space, 1408 sq. ft., with 12′ ceilings should require less than 50,000 BTUs.
RE: CMU
Its not a good way for plumbers to increase profit if they are being paid for installation only, and not as a middle man for purchasing the boilers.
When it comes to the cost of the boiler the models in the same series are all in the same ballpark (obviously larger costs more, but its within reason). My building is 22×64 with 12′ ceilings on 4 floors. the 130k works great and get the place warm fast whish is what i wanted.
Hmm, Hancock, how humungous are your units? My 3000sqft 4-floor semidetached with probably little insulation, has ONE 150kbtu for steam heat (less efficient than hot water)!
To OP: Most installs are oversized, a good way for the plumber to increase profit (amd, to be fair, never get a too-little-heat complaint.) Get a heat loss check done before you agree to the size, For one thing, the lower floor will probably need smaller units. Check into Munchkin hi-efficiency units, and also combining the boiler-hot-water units.
I’m looking to have the same thing done. Could either of you please provide a recommendation.
Thanks,
Robert
Thanks. I will look into the burnham brand. I was quoted $7500/unit for the installation which includes the price of the furnace $2300/unit. I have also been quoted $700/ unit for the furnaces by a different plumber with comparable installation costs.