Intermittnet shut down to save $$$

hotwired

Good day,

This is a newbie question but I really haven't found a clear answer yet, so here goes (two questions actually, but related)

1. I own several apartment buildings, mostly HWBB oil with elec. domestic hw heat though some boilers have external boilermate (indirect) -- I am always trying to dream up creative, low maint. ways to save energy costs. Two ideas - one that's common, one that's not:

First Idea: using timers to shut off HW heaters (elec.) at night, or in the case of one building, I have 2 40 gall. daisy chained, so maybe shutting ONE off from 9 PM to 5 a.M. AND hope that the one remaining is enough. I'd also like to find the answer to the quesiton "do you really save money by shutting off an electric HW heater at night..." (PS my basements are all spray foamed and very warm and I live in Central Maine)

second idea: Actually use some sort of timer to ACTUALLY kill my boilers at night for example, 20-40 minutes at a time.  ALTERNATIVE IDEA: simply kill circulators during the night for short periods so that heating calls are "ignored" ...? Any ideas along these lines would be great.

meplumber

Neither idea is very savy IMHO.

I am in the MDI area and have seen building owners try just about everything to save a few pennies.



The only thing that seems to make any real difference is some sort of outdoor reset control for the boiler.  I always get the look of "I don't want to spend that kind of money".  But they are always sold a year later and I put it on their other buildings.



Any time you turn off your water heater or boiler and you let it cool down, it requires btu's to bring it back up to temp when you need it.  There are a large number of arguments out there for how far you can setback a thermostat at night before you go beyond the recovery point and it costs more to bring it back to temp.



Look into outdoor reset control on the boilers and maybe new indirects.  The new ones have much more insulation than those electrics.



Good Luck.

icesailor

Shut Down to Save:

Personally don't think you save a dime when turning water heaters off at night. The stand-by losses in water heaters aren't high enough to make them come on.

If I just got home after driving from Colchester VT after ice sailing all weekend and it was 1:00 AM and I wanted to take a shower, and I hadn't enough hot water, your ears would be burned off from my verbal abuse. And some places have regulations covering landlords providing domestic hot water.

As far as outdoor reset, if you have one boiler doing three apartments, you must set the water temperature to the highest level needed to satisfy the needs of the tenant that wants it the warmest. If it is an older person, it will be warmer.

As far as set back thermostats, I have used them for many years with good results. You have mentioned the con's of them from the anti setback thermostat crowd. They must be right. If you turn them down too much, it costs more to bring the heat back up.

Like in my home. My high temperature is 68 and my low is 58. A 10 degree spread. I'm off from 8:30 AM to 4:30 PM and off from 9:30 PM to 4:00 AM. Off for 14.5 hours. I designed for Zero. Yesterday, I was sitting in a room with a big digital thermometer that gives inside/outside temperatures. At 8:30 AM, the temperature outside was 30F and the inside was 68F. At 4:30 PM when the heat switched on, room temperature was 61F. The burner never came on for 8 hours. In less than an hour. the room temperature was at 68F but the burner was cycling on high limit. My system temperature high limit is 160F and my low limit operating setting is 140F.

I haven't figured out how my burner, running 45 minutes to bring the zone up from 61F to the setting (68F) costs more to do than not having the burner run for 8 hours and never getting to the low set point. But they know something I don't know.

Outdoor reset has it's place. But if you have apartments with differing heat needs and losses, cranky tenants will drive you nuts. And unfortunately, current outdoor reset can not distinguish between a physical drop in outside temperature (temperature actually drops) where the system needs to go up, and a theoretical drop (wind comes up but the temperature doesn't go down) and the heat loss in the building goes down but the system temperature doesn't go up. The building gets cold and the tenants get cranky.

If you want to make improvements, you need to consider zoning. Someone with understanding needs to look at your system and see if it can be judiciously zoned. Especially if you can separate the North side from the South.

I hope this helps,

ABSolar

money saver

Try Intellidynes "Intellicon HW plus".  It is similar to outdoor reset, reduces burner short cycling and usually saves a minimum of 10% fuel during the course of one year.  Payback typically ranges 1-2 years...Brookhave Labratory (Fed. gov't) tested and reccommended.

hotwired

intellecasters

I call them IntelliCasters (after my favorite guitar) -- I just installed two actually, on a 5 and 6 unit .  It does say they'll even give your money back if you don't save minimum 10%~!

maine rick

shutting boiler down at night

being in southern maine and doing service work on oil units.  in jan. when we had that cold snap between frozen pipes and splits i could not give you a total count. do not play with boilers to save oil in the long run it could cost you more. everyone that had issues with frozen pipes/splits all said they lowered there thermostats at night.

it cost money to save money i would insolate the buildings first the if your boilers are 20to 30 years old then upgrade them.

water damage is not fun.

hotwired

frozen pipes

Thanks for that. I like hearing from pros. I actually had m first frozen pipes this winter which were actually CAUSED by our weatherization. (old, OLD buildings and we foamed the basements and as a result, heat was stopped from getting "out" to a couple of domestic HW pipes that were outside the building envelope) But that's ok! We fixed the problem and should have ZERO. I think frozen pipes are probably something that needs to be factored into the cost of any major weatherization project on old buildings. Anytime you "screw" with somethng that's been a certain way for 50 years SOMETHING is bound to happen!

I was curious though, do you mean to say that your frozen pipe clients had simply turned their thermostats down to, say, 65 degrees during the night or something like that???

maine rick

replying

they go 60* and lower.

people are funny sometimes. they think nothing of buying a pellet stove for $5,000. to save on oil for about 4 months out of 12. but will not spend around $2000. more on upgrading the boiler for a 12 month saving.

what part of maine are you in. i live in biddeford now but grow up in mexico.

hotwired

2,000 more

That's a good point and I'm glad I read it NOW...I was getting itchy to put my first pellet stove in!!!  Of course the question that begs to be answered, is "how much energy is used for the rest of the year" -- I have a 4 unit, 7 unit and 2 unit that have electric HW heaters (brand new) so my furnaces (2 brand new pensotti direct vent oil fired) only run during heating season anyway. I've toyed with the iidea of backup wood boiler for my larger buildings (7 and 11 unit) because i ALWAYS have a tenant willing to have a few bucks shaved off rent in exchange for stoking the boiler.

Will my decision to use electric be wise? I don't know, but many savvy landlords around here (Waterville Winslow Maine - 20 miles north of Augusta, 90 miles north of Portland) have done this "mix".  If oil goes thru the roof, at least our water is taken care of by elec. and if elec rises horribly then at least our heat is handled via oil. The pensotti direct vents with accept a gas burner too, from what I understand, so if we ever get natural gas in this area, we can switch over ... at least I think we can. My layman's assumption!!

ABSolar

savin' money

Hi hotwired,

you can save even more as a landlord by installing simple solar hot water.  By pre-feeding your electric hot water tanks w/ solar heated water, you probably can hit a solar fraction of 90% for 1/2 the year (which means 90% energy savings for domestic hot water!)  Let your boilers do the hot water heating in the winter, as you already have been doing.  The swing season months of April, May, September, October are still good for solar augmentation.  If you're bold enough, you can just let the solar system run full year round to hit a solar fraction of 70% AND still switch from electric back to boiler backup heated water come November.  Just because you're in Maine doesn't mean solar can't work - Germany's been doing it years now and they get less sun than you. 

hotwired

solar payback

I actually got full estimates for my 11 unit (2 buildings, 5 and 6 units each almost connected) The estimate was for $16,000 for one building, $18,000 for the other and with fed and state credits, brought it down to $12k and $14k, give or take. About 3 x the price of a new boiler for each building. Payback was about 15 years. Not quite as quick as a CD I'm afraid. They may have been high, but my perspective is we're about 5 years or so away from solar being a viable option investment wise. I could be wrong, but it seems like it's still in its (relative) early stages and priced very high.

ABSolar

solar tax credits

Hi hotwired,

Something doesn't jive w/ your numbers- a quote of $18,000  should see a 30% fed tax credit alone ($6000) bringing it down to 12,000.  I don't know what the Maine incentives are but wouln't that bring it even lower?

ABSolar

Reasons to solarize...

And doesn't the thought of free energy AFTER the payback point for an additional 15 or so years wet your appetite?  Money in your pocket...after tax dollars!

hotwired

adjustment

Yes, actually re figuring it's approx $11,000 and $10,000 for total of $21,000. (Maine = $1,500 per/Fed 30% per)  The solar estimator estimated a 300 gallons per building savings (600 gallons total). Which, at $3 per gallon would be $1,800 and $4 per gallon $2,400.

Payback would be approx. 8.75 to 11.6 years.

I would get a much better return, IMHO simply buying another apartment building, honestly. I tend to have a 4-5 year tolerance for payback. I use this logic in most dealings like refinancing, etc. It's a personal thing, not a blanket right or wrong, I just feel 4-5 years is as far as I personally want to go out. And specifically with solar, I have an idea that a good chunk of the price is due to the R & D, rebates, etc. I just have a feeling waiting 3-4 years will bring cheaper technology, then I'll jump on it~!

ABSolar

Pondering the money...

OK, so if you can start saving 2400 a year, in 3 or 4 years you could have saved 7200 or 9600 in that time period.  I DON'T think that the technology will improve to the point of lowering the equipment costs on the systems you want by THAT amount - do you?  Also, fuel pricing will climb some in 4 years time, AND labor to install probably will, also.  And, we are talking after-tax dollars, to boot...just pondering   

hotwired

thoughts

Those are good thoughts. I'll have to do some pondering. Of course ... some of it is emotional. We have 68K in repairs and upgrades (mostly weahterization) in 6 months time, so we're a little cautious now! (11 unit building, paid 180K for it, and we'll be getting 22k back in energy rebates, so once we do, we might just ponder the solar issue a bit more)