This word may derive from "hearth", meaning home or family life.

Hearthy (adjective) - derive from "hearth" (noun, the floor at the bottom of the fireplace in a room.) ~ homely and family. -- making people feel comfortable and warm, as if people were in their own home or family. Smell (noun) ~ the quality of something that people and animals sense through their noses. In Chinese: Deep = 深沉的，濃烈的 Hearthy = 壁爐的，家的，家庭的，家居的 Smell = 氣味，氣息，味道 Hearthy Smells = 家的氣息，家的味道 The Yellow Birds: A Novel by Kevin Powers Chapter 3 March 2005 Kaiserslautern, Rhineland-Palatinate, Germany ... I'd had to walk a half a mile or so to get out the security gate and another two until the first row of buildings appeared on my left. The sky was now less brightly lit, and there was a steady, fine mist that hovered in the air. In the plane, the sun had a kind of buoyant dominance, but it had hidden itself away beyond clouds that appeared like pale, soot-colored sketches of themselves. The buildings were more colorful than I thought buildings could be, with light pastel trims, and rich creams and yellows thickly painted on the stucco walls. I walked toward the town, past softly lit cafes emitting deep, hearthy smells, past solitary people walking on the street, the collars of their slickers pulled tightly around their necks, their eyes pausing to evaluate me. Without fail, they turned toward some other ending for their travels. ... [Chinese Translation] Kevin Powers 的小說《黃鳥》 第3章 2005年3月 德國，萊茵蘭-普法爾茨州，凱澤斯勞滕市 (該鎮是位於德國西南部接近法國邊境的一座小城，與著名共產主義祖師爺卡爾•馬克思的故里Trier特里爾相鄰。) …… 我只好從這道防盜門起再經過了另兩道防盜門，又走上了半英哩左右路程吧，這時在我的左手邊就看到了頭一排樓房。現在天色還不咋亮，氣溫也沒咋變，空中薄霧嬝嬝如仙氣般繚繞著。在飛機上看的時候，太陽總是具有一種蓬勃上湧的氣勢，可它也多隱身在雲層後面，就像一幅幅蒼白而又烏黑的鉛筆素描畫一樣。但此刻這些樓房五彩斑斕的程度卻遠遠超出了我的想像，光亮的彩粉瓷磚以及鮮明的奶油色和黃色都被濃重地塗在了外牆上。我漫步在這小鎮上，走過一間間燈光柔和的咖啡館，它們彌漫著濃烈的家居氣息；也走過一個個在這條寂寥街道上踽踽獨行的路人，他們的雨衣領子都豎起來緊緊箍在了脖子上，他們的眼光會瞄著我上下打量一番。毫無疑義，這些傢伙都註定會轉入他們旅程的某個終點。 ……

The hearth is the floor-part of the fireplace, which can extend into the room. "Hearthy smells" would mean any kind of smell you would associate from being near a home fire - warmth, cooking and so on.