Hey guys,

I am wondering if anyone has discovered a successful tactic for retrofitting homes with hydronic baseboard heating.

We are located in the NorthEast and the frequency of oil fired hydronic heating systems around here is extremely high.  Most of them are baseboard systems.

We have explored the possibilities of a Heatpump/Oil split system with HP lockout during the coldest weather.

Our largest problem is the temperature differential in the hydronic systems.

Has anyone had luck with replacing baseboards to higher surface area units, working around the operating temperature of the systems, or supplying backup heat?

There is a large market out there full of people who really cannot afford to replace their entire heating system.

Thanks,
TylerP @ BluSource

Tyler, we had a long discussion on this a month or so ago and more or less threw our hands in the air. It comes back to footprint. The reletively small footprint of a conventional baseboard offers too few btu's at 110 degrees or so. Higher temp Climatemasters plummet from the 140 or so degrees promised during cold weather. Electric baseboards that take advantage of all electric heat discounts from utilities combined with split system heat pumps or infloor radiant (using OSB embedded tube) are all I can think of without adding ducts.
Good Luck,
Joe

Hey Tyler

I am from RI also and in the same situation as you. Oill fired hydronic system with baseboard. I have been investigating geo since last spring and am being cautious about progressing because of the high cost of installing a whole new heating and cooling system. I have just received my latest estimate for a new sytem and it would be just under 50K. Oil is currently at just under $3/gal. I think I could save $2,000 to maybe $2,500/year with geo. That is an awfully long payback period.

I am continuing to look for less expensive alternatives to geo. There is a company in Maine that is developing an entire system of heating using a Bosch pellet fired boiler in your basement to replace your regular boiler. Pellets are delivered in bulk in what looks like an oil truck(4-5 tons/delivery) into a hopper in your basement. An auger automatically feeds the boiler from the hopper. Very litttle work is required on the homeowners part. The cost to install the system was about 12K if I recall correctly. Cost was estimated to be equivalent to oil at $2/gal. The system is only in Maine at the moment but if successful would probably spread through New England.

I am not saying this is the best thing to do, but I think a careful investigation into a wide variety of options is well worth it.

Thank you both for the replies. I like the idea of the pellet boilers but I believe that geo is, on the whole, a much more responsible and economical option.

We are going to make every effort to use open loop systems to keep the water as close to 50* as possible.

We are also considering ways of adding oil backup or electric resistance heat when needed. The trouble is "sharing" the baseboards.

We are investigating preheating the ground water or refrigerant, as well as cascading systems to get that high temp output.

For hybrid systems, has anyone looked into replacing high use rooms with a console (or hotel) unit? You could lower hot water temperature or even turn it off for a large part of the time and heat just the used areas of the house.

We have looked into that type of heat delivery method. Despite being somewhat unsightly they do seem like a viable solution.

What we would most rather do is to incorporate any systems changes at the heatpump loaction, ie. the basement.

Discussion on it said the only possible thing is
Climatemaster THW Water to Water HP
but even that won't get you to the design temperature, at least not at normal northern ground temperatures.
Best bet would be to hook it up to an open loop. Honestly, you'd be doing an experiment with it, and you'd have to worry about covering a failure.

We are lucky enough to have an experimental house. The house currently has Oil fired baseboard heating. The house is 2200sq.ft., we derived a manual J heat load calc of about 51,000btuh. The house, as can be expected, has way too much baseboard heating, but not enough to operate at 120*.

Geo system #1 is a typical standing colum well setup with two water:air tranquility heat pumps, one for each floor. Ducting and air handlers will be installed.

We're going to keep the baseboard heating and plumbing for the water:water experiment. We will utilize the same well as we expect very high water production.

The THW hp definitely grabs our attention. If by the time we are ready there are no more advanced units from another manufacturer, we will problably chose the THW.

I'll keep you guys posted if I learn anything "groundbreaking." Thanks a lot for the help and suggestions so far.

-TylerP

I'm a Climatemaster dealer and not comfortable with a THW/ baseboard application. Again, when you need it most, the 140 degree water won't be there.
DK, how are you only saving $2,500/yr with geo vs fuel oil? A twenty year payback is inferior to most any other investment. Start your own thread with design info and we'll see if we don't have better ideas.
Blusource, there are many types of wall units with different appearences. All, I think, are more attractive than a fuel oil fired baseboard.
J

My mom, youngest of 3 children, has memories of trekking down into a cold basement to 'feed the worm'. The worm was the auger pushing coal into the furnace of their Binghamton, NY home. Periodically coal had to be pushed / pulled to where the auger could get at it.

Funny how an old old idea comes back around. I'm far removed from my New England roots, but I have read that wood and wood pellet prices are rising steeply up there. Unless one has one's own wood lot, I'd be extremely hesitant to become dependent on wood fuel supplied by others. I'd be curious to know long term combustion efficiency of a solid fuel burner (heat exchangers becoming fouled with ash) as well as any health issues possibly associated with whatever chemicals are used to turn wood into pellets (some sort of binder is involved, I'm guessing)

In New England, probably 50% of the houses are oil fired hydronic baseboard systems.

When you think of the houses that are on lots in which well drilling is easily plausible, that jumps up to almost 75%!

I personally am a huge fan of burning wood, but that is because my father builds residential houses and we have an almost unlimited supply of timber. Keep in mind, we burn this in a wood burning stove in the living room. We still have oil fired baseboard, and use it consistently.

I would wonder why the THW couldn't keep up in cold conditions outside. It should be able to build up temperature relatively quickly in the baseboard systems. Since the baseboards operate via convection, they will barely shed any heat below 100 degrees. I would think that the heatpump could therefor get the temperature up to about 120-140 before it really sees a big load. I don't have any evidence to support that, just an assumption, and welcome discussion!

As for payback periods, if we have to go in and install an entire heating system, i.e. new complete forced air system in a 2 story house, the cost is extreme. Upwards of $30,0000 easily. Keep in mind, everything is more expensive up here (labor + materials) Then the customer still has the old baseboard system sitting there, still looking ugly.


To me, tearing out a perfectly operational heat delivery system just doesn't make sense. A customer with baseboard heating doesn't really see the attraction of spending $30,000+ for a 14 year payback period. The average home owner stays in the home for about 7 years. Its hard to explain to someone being hammered with oil heating bills that we can't really help them, because the heatpump doesn't fit in their house.

Imagine a variable output temperature heat pump that could put out 170*.  All we would have to do is improve attic insulation and replace the boiler with a heatpump.  That would cost under $15,000 easily.  Quick payback.  Imagine the market share and notariety that the geothermal world would open  up, overnight.  I think we would ALL benefit.  This is a duscussion worth discussing!

The THW, offers 140*

Sorry, the THW offers the peak of 140 ish degrees, but that is affected by entering water temp. So again, during the coldest part of the year your output would be less. Your 170 degree desire for geo is out of reach with todays technology and I think out of the question with R-410 (I'll let engineer do the math on that head pressure). Give us ducts or higer density in floor tube and geo can help.
j

I do understand the limit of the THW as being 140*. I also understand the limitations of R-410a, but that is a limitation of the refrigerant and certainly not the refrigeration cycle. We can, and will continue to make advancements to heatpump capabilities and efficiencies.

We implement mainly standing column ground coupling systems. This, combined with an automated bleed, provides a pretty stable ground water temperature.

We'll explore this a bit more in the coming months and I will definitely post the results.

Thanks for the wealth of input joe.ami. I know that I'm asking for a lot here, but I think its a worth while venture.

Dave,

Its very interesting that you should mention that. My coworker and I had a conversation about "standard" setups for all the different types of existing heat delivery systems. Air Source seems to be more economical if you need to shut off the heat pump and switch to oil. A house that already has forced air is much easier to retrofit.

We haven't tested a way to keep the heat pump running in the background while the original burner adds that extra 50 degrees. We do have some interesting ideas though.

The important thing to keep in mind is that fossil fuel burners tend to create a lot of heat very quickly.  A typical oil fired burner will get the water hot in a matter of minutes while a heatpump may have to work for quite some time to get the temperature to its maximum range.  It all depends on load.  I think the baseboards are good in this respect in that they do not offer a significant load at low temperatures, letting the heatpump create the large temperature differential quicker.

Off the top of my head I think the only way to crack the hydronic nut with geo will be via two stage systems. By two stage I don't mean two speed but rather two entirely separate refrigeration cycles each likely employing a different refrigerant in dedicated compressors.

The first would operate at typical geo conditions - low side at 40 F, high side at 100 F or so. Second system would work off of first system's high side as its low side. Second system's high side might then be able to be well into the 160-200 F range needed for baseboard water.

I believe this is essentially the reverse of how cryogenic (very very cold) freezers work. I don't know if there are any systems or any refrigerants yet in use at 100 / 180 Deg F conditions. The pocket protector crowd at Copeland and Dupont might have to break new ground. I don't even know if the combined COP for such a system would ever make it economically feasible - heating oil might have to go to $8 per gallon.

I think two stages might be the only way to have reasonable pressures and compression ratios. It may never happen, but given the millions of hydronic houses in New England and elsewhere, there's a buck to be made if someone manages to swing it.