Radiant Heating/Cooling

bhpboy

About to close on a 12,000 square foot brownstone in downtown Boston. The building will be gutted and turned into 6 luxury 2000 square foot condos. Each unit will have its own systems. Trying to decide whether or not radiant/heating cooling should be installed instead of a forced air type solution. I am a novice in this area, so any help would be appreciated. Thanks!

GMcD

Whole building approach

The decision needs to be made based on how well the windows and walls will be specified. Radiant cooling in Boston will require dehumidification through the ventilator/ventilation system. I would strongly suggest you have an engineer and an architect involved who know how to design the whole building to suit radiant systems. Especially for radiant cooling- you will need to have very high thermal performance windows (R-5 or better) as well as good solar gain control via window tints, exterior shading devices or other means. I would suggest that this project would be a good candidate for the Karo Capillary tube system- applied to plaster ceilings with some limited floor warming only in the bathrooms. If you are considering trying to use floor cooling, be aware of the limited capability of floor cooling. Combined heating and cooling radiant from the ceilings would be a much better approach in my opinion.

bhpboy

So sounds as though in the city of Boston Radiant Heating/Cooling may be more trouble than it is worth?

Nron_9

rad cooling

No the cost up front is high but the pay off is verry good for large buildings that why we see radiant cooling in large commercial building now and with costs increaseing we will see more people start to use radiant cooling in the future

bhpboy

Thanks. Since this is an investment and we will be flipping the condos for sale once rehabbed how much more up front costs are required for radiant vs. forced air? Obviously we want to incur as little buildout costs as possible.

bb

upfront cost vs.

comfort. The new owners would be much more comfortable with radiant heating! If you ask the guys in Calgary you will find that many condos and apartments have radiant heating as a standard feature!

Yes, it is more expensive up front, but the comfort is worth the price. I'm sure that the additional cost financed would not add that much to the mortgage payment!

Radiant cooling is a different beast to tame.

bb

GMcD

Trouble??

Depends on how you define "trouble". In my opinion, it would be relatively straightforward to design a radiant heating/cooling system for residential in Boston, but the installation costs would be higher than conventional forced air, but not by much. The payoff with a properly designed radiant system is the energy use will be at least half of a conventional system, and the comfort levels will be much better. If you intend to sell off the units, then I don't think a radiant system would be appropriate - unless you are going to market these places as unique in the area and use the low energy use as a selling feature. If you do that, you might be able to recoup the higher capital costs of the radiant system up front when you sell off the units.

bhpboy

On a percentage basis....how much more do you think a radiant design and installation would be than a forced air system? Does the radiant system take up more/less/same space in the utility room? Thanks for all your help thus far......

Michael_6

Brownstone

Bhp Contact me. we are doing some brownstones currently in town and can show you the projects and get you pricing.

e-mail: michael@heatech.com
office: 781-665-5800

GMcD

Cost premium for radiant

The cost premium for a small building radiant system split into twelve units could be in the range of a 20% to 30% premium capital cost depending on the expertise of the designers and installers, and availability of system components, and building layouts. A "heating only" radiant floor system might not be that big a premium (maybe 10% more than forced air), but you have to look at the "whole building costing"- the "line item" for forced air mechanical might be cheaper, but where does the extra cost for dropped ceilings, bulkheads, duct space and lost floor space get accounted for in the project? Typically a hydronic radiant system with small heat recovery ventilators should take up less space than a conventional forced air system. Adding radiant cooling to a radiant heating system requires some dehumidification to be added to the ventilation system, adding costs, plus you will need a cool water source- more cost. On a small project like this it can be a challenge to justify the premium costs for a radiant cooling system, and it may be a better compromise to use a radiant heating system and add straight supplemental air cooling via the ventilation side.

On large scale commercial building systems, we can actually do a complete concrete core conditioning system (radiant ceiling slab cooling and heating) for less than a conventional HVAC system approach, including the high performance glass and dehumidification. A lot easier to do with the economy of scale.