Remodeling House - What would you do for heat?

Jim R.

Soon we'll be remodeling a raised ranch, 1600 sqft above ground and 1600 sqft in a walkout basement. There will no basement door seperating the two levels, just open stairs just like a two-story. This is a change from our current heating/cooling situation which is working well. I want to have some information going into this and not be 100% reliant on the contractor deciding what to do.

Currently have 1 zone HWBB, indirect DHW on priority, and a 10 year old Buderus gas boiler (79Mbtu). Located outside of Philadelphia, PA.

Two goals:
1. replace the HWBB upstairs which is noisy and banged up pretty bad. Want something more durable and nicer looking.
2. fully heat basement which is mostly unheated (have a gas fireplace to take the chill off in the winter-- but with adding rooms, walls, etc. not sure how that heat will flow). About 1/3 of the basement will be getting a new slab.

I'd like to use the existing boiler and not install forced hot air. If this is a bad idea I'd like to hear but this is
my thinking thus far.

I am leaning towards Myson T6 panels everywhere with TRV values for individual room control. Not sure if it's worth going radiant for the new slab section, about 600sqft, and the panel rads everywhere else.

What are some other options? Using mini-splits for the lower level with rads upstairs doesn't feel like a well planned system. Contractors don't seem to like wall or ceiling radiant even though work is being done in those areas.

For cooling, main floor has A/C in the attic with a few vents going to the basement. The thinking is we may drop another vent and add a permanent dehumidifier. The basement is pretty cool in the summer as is, maybe on the hottest days we could use a little help. Main floor I think will have enough A/C even with the warmer basement air moving upstairs.

Thoughts?

STEVEusaPA

It seems like you have the right ideas. I would keep the boiler, use the panel rads. I wouldn't do the radiant in the slab if you are going to carpet over it, but if it's tiled I would (don't forget about insulating underneath and edges).

If you have the headroom to install and insulate properly, radiant ceiling would be ideal. The only real (imagined) trouble you get from a contractor is if they want to put in dozens of recessed lights. Also running radiant in the walls is not a big deal and very easy to drywall over with a little patience. Otherwise the panel rads would work downstairs too.

I know mini-splits are super efficient, and cheaper to install, but I don't find them comfortable-especially since they are always moving air-can feel drafty (to me).

Dehumidification is key in the summers, especially for the basement. It may not get very hot, but you know it gets damp.
Id avoid scorched air furnace, unless you need it for AC, but you may want to consider it as back up with a heat pump/heat strips. But then you need to make allowances for ductwork.
I think you're best comfort would be the hydronic heat, with odr, properly sized, installed, controlled, and the AC with dehumidification.

Rich_49

Skip all ductwork and minisplits . Check these out .

http://htproducts.com/fan-coil.html

Get a really efficient water heater , flat plate and 2 circs to isolate . Size outdoor unit for A/C and use a buffer (storage tank ) . You will never have to do alot of work when refrigerants change as the only refrigerant you'd have is between the outdoor unit and a refr / water HX .

These things should change the way things are done and possibly give us a bit more market share while we continue to offer better solutions .

njtommy

@Rich those HTP unit look really nice.
Add an EXV and a modulating compressor and it would be an increadable system.

Rich_49

That's what i'm sayin . Think anyone will bother to attempt to increase their profits and grow the hydronics market or will they keep doing what they have been for 30 years , wrong , might I add .

We could pretty much probably steal half the forced air jobs if we got off our high horse , stopped insisting on using boilers and indirects and got on with it ! By the way , the systems would be better since we would always leverage mass . Right off the top of my head , those wanting hydronic and A/C could expect to pay a similar price for better , safer systems that would be more adaptable every time there is a refrigerant change .

In fairness to those who like heat pumps , Chilltrix also has similar hydronic heating / A/C units

njtommy

@Rich when are these units becoming available and did you get the specs yet for these?

Jim R.

Not sure I understand this...

I've seen some panel radiators in passing that had circulation fans. If I remember, output was much higher but so was the pricing. Since I can get the output I need w/o the fan, I didn't look much further there. They did not have A/C capability though.

These sound like mini-splits, except using hot water for heat instead of a heat pump. Is this close? Does the A/C component
dehumidify like a traditional A/C?

I want a reliable, efficient solution but also something not unheard of in the industry. I'm not in a position to service it myself if there are issues. Are these products just coming out? Are there other brands or just HT Products?

How would it work with my existing system? I'd keep the boiler and DHW for hot water, and have a heat exchanger off the DHW with a control to feed these units? For A/C, coolant needs to be run to each fixture from an outside unit?

Since I'd need one in each room-- what's the cost roughly of the smallest "radiator" preferably in the glass finish? Offhand it seems like something for a hotel and not a residence but admittedly I don't understand it fully.

Thanks.

SWEI

Jaga has some very nice options with excellent low temp output, but they don't come cheap.

njtommy

This technology isn't new at all it's been around since the first chiller was running in 1922. You can thank Carrier for this.

I'm not sure if this is a two pipe or four pipe unit.
2 pipe would use the same lines for chilled water as hot water and the same coil as well.

4 pipe will have separate systems two coils in each unit.
One set of pipes and one coil per hot water and chilled water.

The out side unit could either be a heat pump or a standard condenser. Depending on electrical and gas prices it would make sense to run the heat pump until it is no longer cost effective then switch to NG.

Chilled water works just as good if not even better then DX type cooling.

Rich_49

Chilltrix also has these type units . Ductless splits are for anything but residences but they still are in many homes now . Evolve or die ya know .

http://www.chiltrix.com/

njtommy

Dehumidacation is very important, but if properly sized to get long run times you will have no problems.

Typically in commercial buildings we use hot water coils, hot refrigerant and electric strip heat to dehumidify if straight AC can't do it or if high humid days occurr with low loads.

Jim R.

This is all very interesting but doesn't seem very mainstream for a single family home. Sorry. :-(

I like the idea of a central thermostat, or maybe two, with individual rooms that can be set "a little cooler" or "a little warmer". This is why constant circulation and TRV's are appealing. True, it doesn't address A/C but I don't think that's as much of an issue for us as heat.

These systems seem like a great fit for multi-residences and hotels where people want to set fixed temperatures for each space. With 4 kids, I'd be worried about checking temps in every room in addition to making sure the lights were turned off!

Ultimately it seems like a lot more costly retrofit with
more considerations. Sounds like I'd be getting rid of everything I have now (boiler, DHW, AC), the per rooms cost for each unit is probably 2-3x what a Myson costs, plus the central heating/cooling units. If someone wants to PM me some numbers to make it sounds competitive, I'm all ears.

njtommy

Doing AC is going to be your bigges problem. Adding ductwork is going to take away from your sq ft. Ductless systems are nice and are capable of dehumidifying, but they drive the space temp down about 3-4 degrees to achieve this.

With rads and trvs heating system will perfectly fine, but would design them for low water temps and a modcon boiler. You would be able to run 95% efficiency all winter long.

Jim R.

The thinking is we won't need to add much A/C ductwork. The main floor is already ducted from the attic, the basement has 3 small drops currently. An additional drop is suggested for a 20x20 area on the north side of the house. The basement will also be getting the heavier cool air coming down the stairs from the main floor.

The Buderus boiler isn't modcon but can we can still design for lower temps? Its AFUE is 85% and only 10 years old so I hate to upgrade. Does that 10% difference mean I'm wasting 10% of my gas usage every month?

Current gas usage in winter averages 180ccf/month (130 - 225 range) and is about 17ccf in the summer for DHW only (2 adults and 4 kids).

Jim R.

Oops, that 180ccf/month avg includes a gas fireplace (fully vented). But I have no idea how much the boiler uses by itself.

:-|

JUGHNE

Was your basement door closed before? How close is the return air grill to the stairwell opening?

Jim R.

Yes, we have a basement door that will be removed and the stairway permanently opened to the basement. The A/C return is not far from the top of the steps, maybe 6ft or so.

JUGHNE

How well did the AC system cool the basement before? With the door open/gone the air flow should improve a lot. My guess would be that if you can get air flow thru your new rooms just to remove the humidity and freshen up the air your AC would cover it. It is common to undercut those basement doors to get return air flow out of the rooms.

Jim R.

No issues with A/C in basement. On the hottest days it might get a little warm especially if the door is opening a lot but most of time it's very comfortable in the summer even with the A/C off.