Staple-up, something else, or move?

Couriot

Background:  

We live in a two-unit condominium in the Boston area.  Rubble foundation insulated with icynene.  Originally each unit was heated with a gravity-driven hydronic system.  

 Our unit encompasses the entire ground floor and part of the second, and half of our ground floor (three rooms totaling around 600 square feet) is above the other unit’s side of the basement.  Basement floor is a thin, uninsulated slab.  

 Two years ago, the owners of the other unit replaced their oil boiler with a mini-split system (originally the plan was just to add AC, but complications and perhaps a desire to get rid of the radiators led to a decision to have the new system provide heat, as well).  

 Problem

Previously we benefitted from some heat coming off of the massive basement piping. Unfortunately, with the new system, there is no heat in that half of the basement, and our floors are now unpleasantly cold for most of the heating season.  It’s not like living over a crawl space, but it’s not much better, and it has completely changed the experience of living here.  Last winter was brutal.

Details

Many years ago, I replaced a 1960s gas boiler running on gravity with a mod-con.  I recently had to replace that boiler, but system still works beautifully.  The massive old radiators mean that water temps seldom go above the 120s and are much lower for most of the heating season.

When our system was originally set up, provision was made for an additional zone that remains unused.  

Floors are maple strip flooring over boards.  The joist bays are open.  

Question

My question is, would some type of staple-up make the place more livable (or would it just drive up our gas bills and make the floors even creakier than they are already)?  If so, what would work well?  Are there other possible solutions that come to mind?  

 I know we don’t discuss pricing on this board, but I’ve heard mixed things about radiant in these situations and there is, as always, a cost vs benefit calculation.

 I have an excellent heating and plumbing contractor I’ve used on several jobs, but don’t want to waste his time if this is a fool’s errand.  Thank you in advance for any advice!

JMWHVAC

If I understand your question, “Would adding stapleup to warm the floors and leaving the radiators to also provide heat be a good option?”

The answer is YES, YES! The important thing would be the balancing between rads and floor heat so you get as much heat from the floor as possible. If the floor is not too thick it would be possible to get all your heat thru floor and eliminate the rads where the floor heat is, but leaving the rads gives more flexibility and output.

hot_rod

Start at the beginning if you can, which would be a heat load for those rooms. That helps determine what the floor could provide or add.

The R value of the wood floor build up plays part of the required SWT to warm the gfloor and provide the BTUs/ sq ft you need.

Yes, if you add heat to an unconditioned space it will add fuel costs. Insulation below limits downward loss.

The bigger issue with wood movement is the control of humidity. Wood is highly hydroscopic, it takes on moisture from the air around it. Controlling humidity is critical with wide bvoard width flooring. Limiting the floor temperature at the transfer plates helps lessen wood movement and noise also.

It sounds like you benefited from the neighbors piping heat loss, so he was covering some of your heat costs?

I feel warm floors are about the best heating method, but panel rads are a close second. Maybe just insulating the floor area would help some.

EBEBRATT-Ed

You could try insulating the floors first. Put something up that will be easy to take down if you decide to install radiant you can then reinstall the insulation.

It would be better to do the design first and find out if the insulation alone will help. If you go with some radiant it should warm the floors insulate below it well and you heating costs should not increase much if at all